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Colorimetric Determination of Traces of Metals
... Spectrophotometric method A. Complex formation reaction involving iron(III) and thiocyanate is a well known reaction that has been widely used for trace level determination of iron [18] . The present method is based on the oxidation of LPZ by a known excess of bromate-bromide mixture in hydrochloric acid medium, reduction of the residual oxidant by a fixed amount of iron(II) and subsequent formation of iron(III)-thiocyanate complex which is measured at 470 nm. ...
... The conditions for the determination of iron(III) with thiocyanate are well established [18]. Hence, various parameters associated with the oxidation of LPZ by bromate-bromide mixture and subsequent reduction of residual oxidant by iron(II) were optimized. ...
... Hence, various parameters associated with the oxidation of LPZ by bromate-bromide mixture and subsequent reduction of residual oxidant by iron(II) were optimized. Although nitric acid or hydrochloric acid medium can be used for the complexation of iron(III) with thiocyanate, [18] the latter was selected, since nitric acid, being an oxidizing agent itself, would interfere with the oxidation step of the reaction scheme. Sulphuric acid medium, although convenient for the oxidation step, was not preferred since it is reported to reduce the colour intensity of iron(III)-thiocyanate complex. ...
Two sensitive spectrophotometric methods are described for the determination oflansoprazole (LPZ) in bulk drug and in capsule formulation. The methods are based on the oxidation oflansoprazole by insitu generated bromine followed by determination of unreacted bromine by twodifferent reaction schemes. In one procedure (method A), the residual bromine is treated with excess ofiron (II), and the resulting iron (III) is complexed with thiocyanate and measured at 470 nm. The secondapproach (method B) involves treating the unreacted bromine with a measured excess of iron (II) andremaining iron (II) is complexed with orthophenanthroline at a raised pH, and measured at 510 nm. Inboth methods, the amount of bromine reacted corresponds to the amount of LPZ. The experimentalconditions were optimized. In method A, the absorbance is found to decrease linearly with theconcentration of LPZ (r = -0.9986) where as in the method B a linear increase in absorbance occurs (r= 0.9986) The systems obey Beer’s law for 0.5-4.0 and 0.5-6.0 μg mL -1 for method A and method B,respectively. The calculated molar absorptivity values are 3.97μ10 4 and 3.07μ10 4 L mol -1 cm -1 formethod A and method B, respectively, and the corresponding Sandell sensitivity values are 0.0039 and0.0013 μg cm -2.
... Thiocyanate is an old reagent used for the determination of Iron(III) in 1853 [1]. Later, in addition to Fe(III), it has extensively been used directly or indirerctly, for the determination of some cations such as Bi(III), Co(II), Zn(II) and Mo(VI) [2][3][4][5][6][7][8], anions such as, F -, Cl -, CNand SCN - [9][10][11][12][13][14][15][16] . The determination of SCNitself by using Fe 3+ was an important test to indicate its level in serum and saliva of smokers [17,18]. ...
... in case of NaCl ). Therefore, attempt was concentrated on minimizing the causes of the instability which thought to be due to the inner redox اﻟﻜﻴﻤﻴﺎء ﻟﻌﻠﻮم اﻟﻮﻃﻨﻴﺔ اﻟﻌﺮاﻗﻴﺔ اﻟﻤﺠﻠﺔ -2011 -واﻻرﺑﻌﻮن اﻟﺜﺎﻧﻲ اﻟﻤﺠﻠﺪ Iraqi National Journal of Chemistry,2011,volume 42, reaction between SCNand Fe (III) and also the existence of some CNS - [3] usually present with or may be produced by SCN -itself. All these factors contributed in the redox performance disturbing the stability of the complex :- ...
... A comparison between the addition and nonaddition of (22 ppm Al 3+ + 479 ppm CN -) in the presence of interferences is given in Fig.(7) which shows the calibration curves for the determination of total iron (III). The evaluation of these two figures and their applications for the determination of a synthetic sample of iron (III), is given in table (3). All parameters shown in this table confirm the usefulness of addition of Al 3+ and CNin the quantities mentioned above. ...
... The dietary Na+ content was determined by flame photometry after acid extraction with 1 N HNO3. The minerals (K + , Ca 2+ , Fe 2+ ) and vitamin content were those encountered after mixing the dietary components, as previously determined (14,(20)(21)(22). ...
... Different lowercase letters above the bars indicate statistically different mean values (p < 0.05). Differences were assessed using one-way ANOVA followed by Tukey's test (n =[16][17][18][19][20][21][22][23][24][25][26][27]. ...
The aim of the present study was to investigate whether chronic undernutrition modifies the response to rostafuroxin in juvenile rats. Chronic undernutrition was induced in male rats using a multideficient diet known as Regional Basic Diet (RBD), mimicking alimentary habits in impoverished regions worldwide. Animals were given RBD – or a control/CTRL normal diet for rodents – from weaning to 90 days, and rostafuroxin (1 mg/kg body mass) or vehicle were orally administered during the last 30 days. Undernourished rats became hypertensive at 55–60 days of age (tail-cuff recording). During the last two days, the rats were hosted in metabolic cages to measure food/energy, water, Na+ ingestion, and urinary volume. Blood and kidneys were collected after euthanasia. Rostafuroxin increased food/energy and Na+ intake in CTRL and RBD rats but had opposite effects on Na+ balance (intake minus urinary excretion): negative in CTRL and positive in RBD. The drug normalized the decreased plasma Na+ concentration found in RBD rats, increased urinary volume in RBD but not in CTRL, and decreased and increased urinary Na+ concentration in the RBD and CTRL groups, respectively. Rostafuroxin decreased the ouabain-sensitive (Na++K+)ATPase and increased the ouabain-resistant, furosemide-sensitive Na+-ATPase from proximal tubule cells in both groups, and normalized the systolic blood pressure in RBD without effect in CTRL rats. We conclude that chronic undernutrition modifies the response of blood pressure, caloric metabolism, Na+ distribution in liquid compartments, mobilization of Na+ from non-osmotic compartments, Na+ and water balance, and activity of renal Na+-transporting ATPases to rostafuroxin.
... Cr(VI) analysis was performed by diphenylcarbazide at 540 nm wavelength, and nickel analysis was determined by diethyldithiocarbamic acid at 395 nm by a spectrophotometric method as shown in Figure 3 (Sandell, 1978). ...
... Chromium (VI) combines with 1,5-diphenylcarbazide in the presence of acid to form a Cr 3+diphenylcarbazone complex, and a purple-colored solution is formed. This only happens in the presence of chromium (VI) (Sandell, 1978). As a result, another reason why the removal efficiency, which is high at pH = 3, decreases at pH = 4 and increases slightly at pH = 4.59, may be hydrogen chromate, another chromium (VI) type in the medium. ...
The availability of clean water is insufficient to meet our needs because of both the rapid population growth and the advancement of technology. Heavy metals introduced into the water as a result of various activities cause major problems and create an unfavorable scenario in terms of sustainability. In this study, a specially designed electrodialysis cell was used to remove chromium (VI) and nickel (II) ions from effluents. The compartments were divided by Ionac MC 3470 cation exchange and Ionac MA 3475 anion exchange membranes. The cathode and anode were made of carbon fiber and stainless steel, respectively. The effects of voltage, initial pH, time, Na 2 SO 4 concentration, feed flow rate, and metal ion concentration on metal removal efficiency, energy consumption, current efficiency, current density, and flux were investigated. The optimum values for 97.9% removal of 50 mg/L Cr (VI) ions in 90 minutes are voltage 25 V, pH = 3, Na 2 SO 4 addition 0.1 g and feed flow rate 50.38 mL/min, as observed. At the end of this period, the concentration was calculated as 1.05 mg/L, the energy consumption was 38.57 Wh/L, the current efficiency was 28.56%, and the flux was calculated as 10.87x10 ⁻⁵ mol/m ² s. Optimal values were observed as 20 V, pH = 3, Na 2 SO 4 addition of 0.1 g, and Q f = 40.3 mL/min for 92.3% removal of 50 mg/L Ni ²⁺ ions in 90 min. The concentration of nickel ions at the end of this period was 3.85 mg/L, the energy consumption was 32.14 Wh/L, the current efficiency was 95.11%, and the flux was calculated to be 37.71 x 10 − 5 mol/m ² s. The study shows that the electrodialysis method can be used efficiently for the removal of Cr (VI) and Ni (II) ions from dilute effluents.
... The precipitate were ltered off, washed several times with bidistilled water to remove any traces of metal ions, nally washed by diethyl ether and then dried inside lab drawer for 4h. Elemental analysis yielded C 43. 24 Carbonate-free KOH and NaOH were prepared in CO 2 -free twice distilled water and standardized against potassium phthalate. Universal buffer were prepared and standardized to [15]. ...
... mg cm -3 concentration range. The sensitivity of the method calculated according to Sandell [24] was found to be 1.56´10 -3 µg in silver(I) cm -3 . For 10 parallel determination of 10 ppm of Silver, the relative error and deviation were found to be 0.7% and 0.022, respectively. ...
imple and sensitive spectrophotometric determination method of trace amounts of silver(I) ion using 2-(4-nitro-benzaldehyde)-benzimidazole-hydrazone has been devised. Silver(I) react rapidly with this reagent and forms a red stable chelate, in weak acid medium, which obeys Beer’s law at 496 nm with a molar absorptivity 6.9 ⋅ 10 ³ l mol cm ⁻¹ and Sandll’s sensitivity 1.56 ⋅ 10 − 3 µg cm ⁻³ . The stoichiometry and stability constant of silver chelate has determined using spectrophotometric, potentionmetric and conductometric methods. Interferences from various foreign ions were studied. The nature of the solid chelate has also studied.
... Samples from strawberry leaves were taken on the 70 th day after planting to determine total nitrogen (Jackson, 1967), phosphorus (Sandell, 1950), potassium (Horneck and Hanson, 1998) and calcium and magnesium (Jackson, 1967). Also, crude protein was calculated according to A.O.A.C (1990) using the following equation: ...
... Samples from strawberry marketable fruits were taken to determine total nitrogen (Horneck and Miller, 1998), phosphorus (Sandell, 1950), potassium (Horneck and Hanson, 1998) and calcium and magnesium (Jackson, 1967), total and reducing sugars (Sadasivam and Manickam,1996), vitamin C and titratable acidity (A.O.A. C, 1990). Additionaly, total soluble solids (TSS) was measured in the juice of fresh strawberry fruits using a hand refractometer. ...
Abstract
This research was carried out to investigate the effect of two soilless culture systems, i.e., solid substrates mixture as an open system and hydroponic (DFT technique) as a closed system on the vegetative growth, leaf anatomy and fruits yield and quality in comparison with traditional soil culture system during 2017 and 2018 seasons. The growth of strawberry plants cv. Festival cultivated in both applied culture systems was significantly enhanced in comparison with the traditional soil cultivated plants (control). Significant increases in the fresh and dry weights of root and shoots, root size, number of leaves and total leaves area/ plant were attained by the applied soilless culture systems, whereas a significant reduction in roots/shoots ratio was occurred. In addition, both applied soil alternative media caused a significant increase in the leaf content of photosynthetic pigments, nitrogen, phosphorous, potassium, calcium, magnesium and crude protein compared with the control. Anatomically, the applied alternative media led to obvious increases in the thickness of mid vein, length and width of main vascular bundle, thickness of phloem and xylem tissues, number of xylem vessels/bundle and thickness of lamina and its comprising tissues (upper and lower epidermis and mesophyll tissue). Moreover, the fruit yield/plant and fruit characteristics namely fresh and dry weight, dry matter/fruit were significantly improved as affected by the applied soilless culture systems compared to the control. Furthermore, a significant increase occurred in the concentrations of N, P, K, Ca, M, crude protein; reducing, non-reducing and total soluble sugars and vitamin C contents as well as Total Soluble Solids (TSS) estimated in the marketable fruits of strawberry plants cultivated in the two soilless culture systems (solid substrates mixture and hydroponic system), while, the titratable acidity % wasn't significantly affected. these advantageous effects on different studied growth, chemical anatomical and fruit yield and quality were most pronounced in case of the solid substrate cultivated plants followed by the hydroponically plants cultivated. These findings, therefore, strongly recommend the use of the applied soil alternative media as effective, safe and eco-friendly agricultural practices in the cultivation of strawberries and other vegetables to improve their growth, productivity and sanitary quality.
... 45 Fe T and Fe(II) were measured using the o-phenanthroline method at 508 nm. 46 All UV−vis absorption measurements were performed employing a PG Instruments UV−visible spectrophotometer, model T80+. ...
Commercial stable zerovalent iron nanoparticles (nZVI) (NSTAR, not activated) combined with ultrasound (US) were tested for Cr(VI) reductive removal (0.3 mM, pH 3, Fe/Cr molar ratio of 3:1) in the presence of the carboxylic acids (CAs) ethylenediaminetetraacetic acid (EDTA, 1 mM) or citric acid (Cit, 2 mM), in a system open to the air. No Cr(VI) decay up to 180 min was observed under US when only NSTAR nanoparticles were used, while other previously tested commercial nZVI (N25) showed about 40% decay in a few minutes but without further Cr(VI) removal. The addition of EDTA and Cit enabled Cr(VI) removal with NSTAR in the absence of US without prior activation of the particles. A pseudo zero-order kinetics was followed, yielding 32 and 49% removal with EDTA and Cit, respectively. When US was applied, these values almost doubled, reaching 59 and 88% for EDTA and Cit, respectively. A mechanism for Cr(VI) decay was proposed. The present results indicate that the simultaneous use of US and CAs allows for a synergistic Cr(VI) removal by NSTAR avoiding the need of an activation step of the nanoparticles, with a more effective result of Cit compared with EDTA.
... were found to be 2.3 and 7.3 ng mL −1 , respectively. The molar absorptivity and Sandell sensitivity [60] are calculated and recorded in Table 3. The limits of quantification and detection [61], defined as LOQ = 10SB/m and LOD = 3SB/m (where LOQ, LOD, SB, and m are the limit of quantification, the limit of detection, standard deviation of the blank, and slope of the calibration equation, respectively), were 7.3 and 2.3 ng mL −1 , respectively, Readily accessible, low-cost equipment, a UV -vis spectrophotometer, can be used to measure a low concentration of Ag + ions by coupling it with an optode membrane. ...
... The slope of the relation verifies Beer's law in the equation mentioned above and gives the molar absorptivity (). Since the sensitivity of the spectrophotometric method is often expressed in terms of the expression 'sensitivity index' given by Sandell [23], the sensitivity of the present method for determining samarium (atomic mass: 150.36 g.mole -1 , λmax of 654±0.5 nm)in the aqueous medium. The molar absorptivity and Sandell's sensitivity (concentration for 0.001 absorbance unit) are found to equal 4.88±0.2×10 ...
A simple analytical procedure is developed and validated for the estimation of traces amount of samarium in aqueous streams of nuclear waste. In this method, the formation of chelation of samarium ion with 3, 6-bis [(2-Arsonophenyl) azo]-4,5dihydroxy-2,7-naphtalene disulphonic acid (Arsenazo III) to produce a reddish purple colour complex which has maximum absorption at 654 nm at pH 2.6-2.8. The intensity of the colour is proportional to the amount of Sm(III). Linear calibration graphs were obtained for 0.31 to 2.78 µg/mL of Sm(III) with a relative standard deviation (RSD) of 1.32 % and correlation coefficient of R2 = 0.999 (n=10). Its molar absorptivity and Sandell’s sensitivity are found to be 4.88x104 L.Mol-1.cm-1 and 2.05x10-5 µg/cm2 respectively. The stoichiometric composition of the chelate is 1:1. The reaction is instantaneous, and absorbance remains stable for over 24 hrs. The system allowed for the determination of samarium with a limit of detection (LOD) (3.3σ/S) of 0.314 µg/mL, the limit of quantitation (LOQ) (10σ/S) of 0.952 µg/mL. A systematic study of the influence of different parameters like pH, the concentration of the complexing agent, the stability of the colour, the volume of the buffer and interference of other competing metal ions. Results of the present method are in good agreement with those obtained by the standard procedure. It is directly applicable for the determination of samarium in environmental, industrial, water and waste streams of the nuclear plant. Â
... This is further supported by their insolubility in water , and high solubility in most of the non-aqueous solvents like chloroform, carbon tetrachloride, benzene, etc. The complexes when dissolved in organic solvents are not very stable and the deep red coloured solution gradually changes to orangyellow.The ligand 4-(2-pyridylazo)-resorcinol has been reported to be a tridentate ligand where the bonding sites to the metal ion are oxygen of the hydroxyl group after deprotonation, and of the azo and the pyridine nitrogen atoms [ 18,19,20]. ...
The lanthanide complexes of 4-(2-pyridylazo)-resorcinol are prepared in solid state. All compounds have been characterized by means of elemental analysis (C.H.N) molar conductance, magnetic susceptibility and analytical spectral studies IR and UV-Visible spectral techniques. While the complexes have additionally been characterized by differential thermal analysis data and are formulated as [Ln(C11H8N3O2)3].H2O Ln = Pr3+ , Nd3+ and Sm3+ ; [Ln(C11H8N3O2)3] Ln = Eu3+, Er3+ and Yb3+ . The results of these studies on the synthesis and structural characterization, suggest neutral lanthanide complexes in which the mono azo ligand being a uninegative (deprotonated form) and tridentate ligand. The absorption spectral profiles suggest a coordination number of nine around Ln(III) ions in the complexes.
... Emil Fisher is acknowledged for the identification of dithizone, which is alternatively referred to as diphenylthiocarbazone or H2DZ [19,20]. For quite a significant period, dithizone has been extensively employed as a reagent for colorimetric analysis of trace metals [21,22]. Dithizone has been acknowledged as a remarkable ligand with the ability to create complex ions, even in solutions with alkaline conditions [23]. ...
This article presents a new approach to measure the concentrations of lead and cadmium in soil marine samples. The technique involves a two-step process: first, the samples are pre-concentrated using liquid-liquid extraction, and then atomic fluorescence spectrometry is used for analysis. In this process, dithizone is used as the chelating agent. During the procedure, a complex is formed between lead and cadmium with dithizone. The researchers also investigated important factors that may affect the efficiency of the extraction, such as pH of the sample and shaking duration. The results demonstrated that the extraction process yielded optimal results within a pH range of 7 to 9, and the ideal duration of shaking was between 10 to 30 minutes. Through stoichiometry analysis, it was determined that the most probable structure of the extracted ion pair complex consisted of one metal ion bonded to two ligand molecules (1M +2 :2HDZ-). The influence of organic solvents on the extraction process showed that the distribution ratio (D) for extraction increased with a decrease in dielectric constant. Particularly, carbon tetrachloride demonstrated a higher distribution ratio (D), possibly due to its lower dielectric constant, which aids in the disruption of hydration shell around metal cations (Cd and Pb), allowing for enhanced coordination between the ligand molecules and metal cations. A previously described method for analyzing Cd and Pb in marine soil was adapted for this study.
... To calculate the final H 2 O 2 concentration, 25 mL of the reaction mixture were acidified with 10 mL of a solution 1:5 v/v of concentrated H 2 SO 4 and titrated with 0.1 N KMnO 4 . The final concentrations of Fe(II) and Fe T (total iron, i.e., Fe(II) + Fe(III)) in solution were measured spectrophotometrically at 508 nm using the o-phenanthroline method [28]. The concentration of Fe T was determined by adding to the sample 0.2 mL of hydroquinone 1% w/v to reduce Fe(III) to Fe(II) and measuring the sample as before. ...
Degradation of toluene by treatment with zerovalent iron nanoparticles and different H2O2 concentrations under UVA light has been analyzed at pH 3. The highest removal of toluene was found with 100 mg L−1 nZVI and 400 mg L−1 H2O2, but 100 and 200 mg L−1 of H2O2 were used in most experiments as the degradation rate was similar. Experiments with Fe(II) (10 and 1 mg L−1) were performed for comparison. Benzaldehyde and bibenzyl were found the main oxidation products. nZVI could be reused without loss of efficiency. A mechanism was proposed.
... The dietary Na+ content was determined by flame photometry after acid extraction with 1 N HNO 3 . The minerals (K + , Ca 2+ , and Fe 2+ ) and vitamin content were those encountered after mixing the dietary components, as previously determined (Perkin-Elmer Corporation, 1968;Sandel, 1959;Snell & Snell, 1967;Teodósio et al., 1990). ...
Hypertension is a pandemic nowadays. We aimed to investigate whether chronic undernutrition modifies the response to the antihypertensive drug rostafuroxin in juvenile hypertensive rats. Chronic undernutrition was induced in male rats using a multideficient diet known as the Regional Basic Diet (RBD), mimicking alimentary habits in impoverished regions worldwide. Animals were given RBD-or a control/CTRL normal diet for rodents-from weaning to 90 days, and rostafuroxin (1 mg/kg body mass) was orally administered from day 60 onwards. For the last 2 days, the rats were hosted in metabolic cages to measure food/energy, water, Na+ ingestion, and urinary volume. Rostafuroxin increased food/energy/Na+ intake in CTRL and RBD rats but had opposite effects on Na+ balance (intake minus urinary excretion). The drug normalized the decreased plasma Na+ concentration in RBD rats, increased urinary volume in RBD but not in CTRL, and decreased and increased urinary Na+ concentration in the RBD and CTRL groups, respectively. Rostafuroxin decreased the ouabain-sensitive (Na+ +K+ )ATPase and increased the ouabain-resistant Na+ -ATPase from proximal tubule cells in both groups and normalized the systolic blood pressure in RBD without effect in CTRL rats. We conclude that chronic undernutrition modifies the response of blood pressure and metabolic responses to rostafuroxin.
... The sensitivity of the photometric method was compared with the specific absorbance (a) (27), which is calculated from the equation: (a = Ԑ/(At. wt of [M]×1000) Where (28) (At.wt) is the atomic weight of the element at a concentration of 1 ppm) in a (cuvette) cell with a light path of 1 cm. The photometric sensitivity is usually expressed in terms of the Sandell sensitivity (s), which represents the amount of micrograms per 1 ml of the solution of the element with an absorbance up to (0.001) and a trajectory of 1 cm and is expressed in (µg.cm -2 ) and is calculated by the relationship: (S) =〖10〗^ (-3)/a) The deviation of the readings (29) was calculated by according to the following statistical relationship: S.D=[Ʃ(Xi-X) 2 /N-i] 1/2 Where X is the average reading of the absorbance values at a constant concentration. ...
The study included the preparation and diagnosis of disulfur ligands (Dithiols) and the preparation of their complex with monovalent (Silver), which included the the following steps: First: preparation of the sulfur compound through the reaction of Grignard reagent (ClPhMgX), with carbon disulfide (CS2), this step form [ClPhCS2]- , an acidic liquid sulfur compound which was converted into a dimer compound by second step :- reacting with (Benzene tetra methyl ammonium hydroxyl) which produce a negatively charged compound [ClPhCS2]-, which is a viscous, hydrated compound with a strong sulfur smell. The product [ClPhCS2]- react with dichloromethane (DCM) which produce (methylene-bis (p-Chlorodithiobenzoate). Which is characterized with (IR,UV-VIS, 1H-NMR, 13C spectroscopy , mass spectrometry) then followed by Analytical study for the prepared compound were investigated by preparation of their complex with Monovalent (Silver), where the stability constants of the prepared complex were studied, which showed the stability of the complex at room temperature and at pH (PH = 8). The absorbance of the complex for UV-Vis. light was studied and the mole ratio (M: L) was studied. From the study of spectroscopic methods.
... A total of 2 mL of sodium citrate (28 mg/mL) aqueous solution, 2 mL of PVP aqueous solution (10 mg/mL), and 2 mL of NaBH 4 (3 mg/mL) were added to 17 mL of H 2 PtCl 6 aqueous solution (0.15 mg/mL). The efficiency of Pt reduction was evaluated using the reaction in which a colored complex of Pt ions with iodide ions is formed in acidic conditions [38]. To obtain a formulation suitable for biomedical applications, nPts were removed from the reaction mixture via precipitation and ultracentrifugation at 140,000× g for 40 min, resuspended in physiological solution, and then filtered through a membrane with a 0.22 µm pore diameter. ...
Platinum nanoparticles (nPts) have neuroprotective/antioxidant properties, but the mechanisms of their action in cerebrovascular disease remain unclear. We investigated the brain bioavailability of nPts and their effects on brain damage, cerebral blood flow (CBF), and development of brain and systemic oxidative stress (OS) in a model of cerebral ischemia (hemorrhage + temporary bilateral common carotid artery occlusion, tBCAO) in rats. The nPts (0.04 g/L, 3 ± 1 nm diameter) were administered to rats (N = 19) intraperitoneally at the start of blood reperfusion. Measurement of CBF via laser Doppler flowmetry revealed that the nPts caused a rapid attenuation of postischemic hypoperfusion. The nPts attenuated the apoptosis of hippocampal neurons, the decrease in reduced aminothiols level in plasma, and the glutathione redox status in the brain, which were induced by tBCAO. The content of Pt in the brain was extremely low (≤1 ng/g). Thus, nPts, despite the extremely low brain bioavailability, can attenuate the development of brain OS, CBF dysregulation, and neuronal apoptosis. This may indicate that the neuroprotective effects of nPts are due to indirect mechanisms rather than direct activity in the brain tissue. Research on such mechanisms may offer a promising trend in the treatment of acute disorders of CBF.
... Bis-(4-fluoroPM)TCH reagent was used for the separation and determination of silver(I) HCl. The residue was dissolved in water, diluted to appropriate volume and metal ions were determined spectrophotometrically by standard methods [48,49,57]. The optical density of silverbis-(4-fluoroPM)TCH-Py complex from organic layer was measured at 375 nm against reagent blank. ...
Intention of our work is to develop cost-efficient, instant, sensitive and synergistic liquid-liquid extraction and spectrophotometric method for determination of silver(I) coupled with N'',N'''-bis[(E)-(4-fluorophenyl)methylidene] thiocarbonohydrazide i.e. bis-(4-fluoroPM)TCH and pyridine. The reagent (bis-(4-fluoroPM)TCH) and synergent pyridine instantly forms stable faint yellow colored complex with silver(I) at room temperature having composition 1:2:2 (M:L:Py) and quantitatively extracted into iso amyl acetate at pH 5.0. The extracted species exhibits absorption maximum at 375 nm against reagent blank. Experimental conditions were optimized and Beer’s law was observed in the concentration range of 1.0 to 7.0 µg mL − 1 of silver(I) and optimum concentration range obtained from Ringbom’s plot was found to be 2–6 µg mL − 1 . The composition of silver(I)–bis-(4-fluoroPM)TCH–pyridine adduct was established by slope ratio, molar ratio & Jobs method. Molar absorptivity and Sandell’s sensitivity value of silver(I) chelate were 1.08 x10 ⁴ lit/mol cm and 0.001µg/cm ² respectively. Selectivity of method was enhanced by use of suitable masking agents. Method has been successfully applied for determination of silver(I) in thin films, nano powders, hypo solutions, photographic wastes, X ray washings, pharmaceuticals, and synthetic mixtures. Accuracy of method was judged by using AAS which tested the validity of method.
... The regression analysis was performed using the least-squares technique [65]. Additionally, the Ringbom's optimum range [66][67][68], the molar attenuation coefficient and the Sandell's sensitivity coefficient [69] were calculated. The parameters of the regression equation are listed in Table 3. Limit of quantification (mg/L) 2.5 5.8 ...
The spectrophotometric methods of determination of the active pharmaceutical ingredients meloxicam and nimesulide were reviewed and a simple UV-spectrophotometric method for the determination of these active pharmaceutical ingredients in industrial equipment cleaning validation samples was proposed. The methods were based on extraction of the residual quantities of meloxicam and nimesulide from the manufacturing equipment surface by the concentrated sodium carbonate solution and the subsequent UV-spectrophotometric determination of the basic forms of the drugs at the wavelength of 362 nm for meloxicam and at 397 nm for nimesulide. The calibration graphs were linear in the range from 5 to 25 mg/L of both nimesulide and meloxicam, the molar attenuation coefficients were 6100 m2/mol for nimesulide and 9100 m2/mol for meloxicam, the limit of detection was 0.8 mg/L for nimesulide and 1.9 mg/L for meloxicam and the limit of quantification was 2.5 mg/L for nimesulide and 5.8 mg/L for meloxicam. The methods were selective with respect to the common excipients, showed a good accuracy (the relative uncertainty did not exceed 7%) and precision (the relative standard deviation did not exceed 4%), did not require lengthy sample preparation or sophisticated laboratory equipment and were suitable for the routine analysis of cleaning validation samples.
... Chromium (VI) combines with 1,5-diphenylcarbazide in the presence of acid to form a Cr (III)-diphenylcarbazone complex, and a purple-colored solution is formed. This only happens in the presence of chromium (VI) [32]. As a result, another reason why the removal efficiency, which is high at pH = 3, decreases at pH = 4 and increases slightly at pH = 4.59, may be hydrogen chromate, another chromium (VI) type in the medium. ...
The availability of clean water is insufficient to meet our needs because of both the rapid population growth and the advancement of technology. Heavy metals introduced into the water as a result of various activities cause major problems and create an unfavorable scenario in terms of sustainability. In this study, a specially designed electrodialysis cell was used to remove chromium (VI) and nickel (II) ions from effluents. The compartments were divided by Ionac MC 3470 cation exchange and Ionac MA 3475 anion exchange membranes. The cathode and anode were made of carbon fiber and stainless steel, respectively. The effects of voltage, initial pH, time, Na2SO4 concentration, feed flow rate, and metal ion concentration on metal removal efficiency, energy consumption, current efficiency, current density, and flux were investigated. The optimum values for 97.9 ± 1% removal of 50 mg/L Cr (VI) ions in 90 min are voltage 25 V, pH = 3, Na2SO4 addition 0.1 g and feed flow rate 40.3 mL/min, as observed. At the end of this period, the concentration was calculated as 1.05 mg/L, the energy consumption was 38.57 ± 0.01 Wh/L, the current efficiency was 28.56 ± 1.5%, and the flux was calculated as 10.87 × 10⁻⁵ ± 0.15 mol/m²s. Optimal values were observed as 20 V, pH = 3, Na2SO4 addition of 0.1 g, and feed flow rate (Qf) = 40.3 mL/min for 92.3 ± 1% removal of 50 mg/L Ni(II) ions in 90 min. The concentration of nickel ions at the end of this period was 3.85 mg/L, the energy consumption was 32.14 ± 0.01 Wh/L, the current efficiency was 95.11 ± 1.5%, and the flux was calculated to be 37.71 × 10⁻⁵ ± 0.15 mol/m²s. Effective removal of Cr (VI) and Ni (II) ions from dilute wastewater can be achieved using a cost-effective ED cell in electrodialysis, with reasonable energy consumption and high current efficiency under optimal process conditions.
Graphical abstract
... Then crude protein was calculated according to the following equation: Crude protein= total nitrogen x 6.25 by (A.O.A.C. ,1990). -Phosphorus content (%): Total phosphorus was determined calorimetrically according to the method reported by (Sandell, 1950) and calculated as a percentage. -Potassium content (%): Potassium was determined by the flame photometer model Carl-Zeiss according to the described method of (Horneck and Hanson, 1998) and calculated as a percentage. ...
... Concentrations of chloride, sulfate, and nitrate were analyzed in water extracts by HPLC with a Stayer ion chromatograph (Aquilon) with an IonPack AS4-ASC column (Dionex) and conductivity detector; the eluent was bicarbonate (1.36 mM)/carbonate (1.44 mM), and the flow rate was 1.5 mLmin −1 . The content of Fe(II) in the mud and enrichment cultures was determined after 24 h extraction in 0.6 M HCl, followed by a colorimetric assay of Fe(II) with 2,2-dipyridyl [26]. ...
The key microbial group involved in anaerobic methane oxidation is anaerobic methanotrophic archaea (ANME). From a terrestrial mud volcano, we enriched a microbial community containing ANME-2a, using methane as an electron donor, Fe(III) oxide (ferrihydrite) as an electron acceptor, and anthraquinone-2,6-disulfonate as an electron shuttle. Ferrihydrite reduction led to the formation of a black, highly magnetic precipitate. A significant relative abundance of ANME-2a in batch cultures was observed over five subsequent transfers. Phylogenetic analysis revealed that, in addition to ANME-2a, two bacterial taxa belonging to uncultured Desulfobulbaceae and Anaerolineaceae were constantly present in all enrichments. Metagenome-assembled genomes (MAGs) of ANME-2a contained a complete set of genes for methanogenesis and numerous genes of multiheme c-type cytochromes (MHC), indicating the capability of methanotrophs to transfer electrons to metal oxides or to a bacterial partner. One of the ANME MAGs encoded respiratory arsenate reductase (Arr), suggesting the potential for a direct coupling of methane oxidation with As(V) reduction in the single microorganism. The same MAG also encoded uptake [NiFe] hydrogenase, which is uncommon for ANME-2. The MAG of uncultured Desulfobulbaceae contained genes of dissimilatory sulfate reduction, a Wood–Ljungdahl pathway for autotrophic CO2 fixation, hydrogenases, and 43 MHC. We hypothesize that uncultured Desulfobulbaceae is a bacterial partner of ANME-2a, which mediates extracellular electron transfer to Fe(III) oxide.
... Additionally, the Ringbom's optimum range [65][66][67], the molar attenuation coefficient and the Sandell's sensitivity coefficient [68] were calculated. The parameters of the regression equation are listed in Table 3. Limit of quantification (mg/L) 2.5 5.8 ...
The spectrophotometric methods of determination of the active pharmaceutical ingredients meloxicam and nimesulide were reviewed, and a simple UV-spectrophotometric method for the determination of these active pharmaceutical ingredients in industrial equipment cleaning validation samples were proposed. The methods are based on extraction of the residual quantities of meloxicam and numesulide from the manufacturing equipment surface by the concentrated sodium carbonate solution, and the subsequent UV-spectrophotometric determination of the basic forms of the drugs at the wavelength of 362 nm for meloxicam and at 397 nm for nimesulide. The calibration graphs are linear in the range from 5 to 25 mg/L of both nimesulide and meloxicam, the molar attenuation coefficients are 6100 m2/mol for nimesulide and 9100 m2/mol for meloxicam, the limit of detection is 0.8 mg/L for nimesulide and 1.9 mg/L for meloxicam, the limit of quantification is 2.5 mg/L for nimesulide and 5.8 mg/L for meloxicam, the methods are selective with respect to the common excipients, show a good accuracy (the relative uncertainty does not exceed 4%) and precision (the relative standard deviation does not exceed 5%), do not require lengthy sample preparation and sophisticated laboratory equipment and are suitable for the routine analysis of cleaning validation samples.
... Quantification of iron was carried out in the College of Natural and Mathematical Sciences research laboratory at The University of Dodoma, Dodoma, Tanzania using spectrophotometric analysis (Sandell 1959). Sample preparation: 10 g of air-dried leaves and 5 g of air-dried calyces were weighed separately and ground into coarse powder and later soaked in 100 mL of distilled water and ethanol separately in four conical flasks and covered with aluminium foil and left for 12 hours. ...
Preliminary phytochemical screening of aqueous and ethanolic extracts of Hibiscus sabdariffa grown in Tanzania revealed the presence of secondary metabolites like steroids, tannins, saponins, glycosides, terpenoids, flavonoids along with L-ascorbic acid (vitamin C) and iron(II). Furthermore, both leaves and calyces showed antibacterial activities (agar well diffusion method) against selected bacterial species (Escherichia coli, Staphylococcus aureus, Salmonella typhi and Shigella sonnei), but calyces possessed potent antibacterial activities compared to leaves. The results also supported the claimed traditional uses of this plant. When interrogated during the cross-sectional study in Dodoma region, 54% of the respondents claimed the plant is used to treat anaemia (supposedly as it increases haemoglobin levels), 23% claimed it is used in the preparation of local wine and the remaining respondents stated use in both areas. Furthermore, the intake of H. sabdariffa leaves and calyces on regular basis can boost the immunity system and helps in preventing bacterial and viral infections as the plant is loaded with flavonoids and vitamin C. Thus, the results observed for the plant H. sabdariffa that is grown in Dodoma in small scale for traditional uses, paves a way for consideration of future large scale production of pharmaceutical and neutraceutical products in Tanzania. Keywords: Phytochemical screening, Hibiscus sabdariffa, antibacterial activity, L-ascorbic acid and iron(II)
... This solution was made to vol ume with H20 . The ferric ion was then mea sured quantitatively with o-phenanthroline (5). The amount of phytate was calculated based on the stoichiometric binding between ferric ion and phytate (4 mol Fe3+/mol phy tate). ...
Phytate rapidly disappeared from pumpkin cotyledons between 3 to 6 days of germination. Phytase, the enzyme responsible for liberating inorganic phosphate from phytate, appeared shortly after germination began, and high activities were found between days 3 through 6 of germination. Large pools of inorganic phosphate accumulated in the cotyledons, shoots and roots during germination. By 15 days of germination, 27% of the phosphate was incorporated into organic materials.
... The unstoppered flask was kept in boiling waterbath for 2 min. The solution was then cooled and the absorbance of reddish brown solution was measured at 400 nm against a reagent blank and gold was estimated by stannous chloride method [35]. The distribution ratio (D) was calculated as the ratio of gold(III) concentration in organic phase [Au]Org to aqueous phase [Au]Aq after extraction using equation, ...
Extractive recovery of gold(III) from succinic acid solution with high molecular weight amine: 2-dodecylaminopyridine (2-DDAP) as a new extractant in xylene has been investigated. Extraction data indicates that 5 × 10-4 mol⋅L-1 2-DDAP is a very efficient and fast extractant. Gold(III) can be effectively extracted (D = 414.16) with 2-DDAP from 0.04 M succinic acid solution. The equilibrium of gold(III) from aqueous phase of succinic acid with 2-DDAP is achieved within 60 sec. The extraction of gold(III) with 2-DDAP proceed at the interface according to ion pair formation mechanism. The best stripping solution from among the studied ones is the 4 M ammonia solution. The selective extraction of gold(III) from some precious and base metals was carried out by 2-DDAP using proposed method and the results obtained are found to be highly effective for synthetic sample.
... MTB is a sensitive metallochromic indicator, which interacts with many metal ions depending on the pH value of the solution, such as Zn 2+ , Fe 2+ , Co 2+ , Cu 2+ , Ca 2+ , Mg 2+ , Fe 3+ , Al 3+ , Bi 3+ , etc. [23][24][25][26]. It is well established in previous reports that MTB has a higher affinity for metal ions with a higher charge, with the greater affinity displayed for metallic ions with the +3-oxidation state [27]. For example, MTB forms stable complexes with Al 3+ [28], as well as Zr 4+ , Hf 4+ and Bi 3+ [29] under acidic conditions, but it can be used for the selective determination of bismuth due to the different maximum absorbance wavelengths and the reaction conditions required for the formation of the metal complex. ...
A novel, direct and simple colorimetric method employing μicroanalytical paper-based devices (μ-PADs) for the selective determination of bismuth is described. The suggested method exploits the colorimetric variation of bismuth after its rapid reaction with methyl thymol blue (MTB) in an acidic medium (pH ranging between 0.7 and 3.0), modified with nitric acid, on the surface of a paper device at room temperature. The devices are low cost, composed of chromatographic paper and wax barriers and the analytical protocol is easily applicable with minimal technical expertise and without the need for experimental apparatus. The user must add a test sample and read the color intensity of the colored Bi(III)–MTB complex formed at the sensing area using a simple imaging device such as a flatbed scanner. Various chemical variables, such as HNO3 and MTB concentration, reaction time, ionic strength, detection zone size and photo-capture detector are optimized. A study of interfering ions such as K+, Na+, Ca2+, Mg2+, Cl−, SO42− and HCO3− was also conducted. The stability of the paper devices is also studied in different maintenance conditions with particularly satisfactory results, rendering the method suitable for field analysis. The detection limits are as low as 3.0 mg L−1 with very satisfactory precision, ranging from 4.0% (intra-day) to 5.5% (inter-day). Natural water samples are successfully analyzed, and bismuth percentage recoveries were calculated in the range of 82.8 to 115.4%.
... −1 are obtained as the slopes of the constructed lines from which the specific absorptivity (a) (ml.g −1 .cm −1 ) [26], corresponding to the absorbance of 1 gµ/ml in a cuvette with an optical pathlength of 1 cm, [27]; µ g/cm −2 which represents the number of micrograms of the determinate per of cm 3 solution having an absorbance 0.001 for pathlength of 1 cm are calculated. All these values are treated statistically and the correlation coefficient and standard deviation are calculated and summarized in Table 8. ...
In this investigation, the azo dyes; 2-(3′-phenyl-5′-pyrazolyl azo) schaffer acid (la) and 2-(3′-phenyl-5′-pyrazolyl azo) resorcinol (Ib); were prepared through diazotizing 3-phenyl-5-aminopyrazole (PAP) and coupling the resulting diazonium salt with Schäffer acid and resorcinol respectively. The prepared azo dyes are characterized using both IR spectra and the elemental analysis (C, H, N and S). The prepared azo dyes are used as chromogenic reagents for the spectrophotometric determination of copper (II), nickel (II), cobalt (II) and zinc (II) ions. The conditional acid dissociation constants of these azo dyes (la and Ib) and the stability constants of its metal ion complexes have been determined by spectro-analytical methods. The effect of pH, time, organic solvent and the foreign ions on the spectrophotometric determination of these ions and their complexes with the azo dyes under study were studied. The stoichiometric ratio (M:L) of the formed complexes was also determined. The molar absorptivity, the Sandell's sensitivity values, the obeyance of Beers law and the stability constants of the formed complexes have been also determined and discussed.
... Of the five calibration graphs, one showing the limit of the linearity is given in Figure 2. The other four were straight-line graphs passing through the origin (R 2 = 0.9993). The molar absorption co-efficient and the Sandell's sensitivity [33] were found to be 6.04×10 5 L/mol.cm and 5.0 ng/cm 2 of cobalt, respectively. The selected analytical parameters obtained from the optimization experiments are summarized in Table 2. ...
A new spectrophotometric reagent, N,N'-bis(salicylidene)-ethylenediamine (Salen), has
been synthesized and characterized through novel reaction techniques. A very simple,
ultrasensitive, and nonextractive spectrophotometric method has been developed for the
determination of the picotrace amount of cobalt (II) using Salen. Salen undergoes a reaction in a slightly acidic solution (0.001-0.003 M H2S04) with cobalt in 20% ethanol to give a light orange chelate, which has an absorption maximum at 459 nm. The reaction is instantaneous,and the absorbance remains stable for over 24 hours. The average molar absorption co�efficient and Sandell’s sensitivity were found to be 6.04×105 L/mol.cm and 5.0 ng/cm2 of Co, respectively. Linear calibration graphs were obtained for 0.001-40 mg/L of Co with adetection limit of 0.1 µg/L and RSD of 0-2 %. The stoichiometric composition of the chelate is 1:1 (Co:Salen). A large excess of over 60 cations, anionsand some common complexing agents such as chloride, azide, tartrate, EDTA, SCN-etc. do not interfere in the determination. The developed method was successfully used in the determination of cobalt in several Certified Reference Materials (Alloys, steel, bovine liver, human hair, drinking water, sewage sludge, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, and milk), soil samples, food samples (Vegetables, rice, and wheat) and pharmaceutical samples and solutions containing both cobalt (II) and cobalt (III) as well as complexsynthetic mixtures. The results of the proposed method for
assessing biological, soil, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy
... Of the five calibration graphs, one showing the limit of the linearity is given in Figure 2. The other four were straight-line graphs passing through the origin (R 2 = 0.9993). The molar absorption co-efficient and the Sandell's sensitivity [33] were found to be 6.04×10 5 L/mol.cm and 5.0 ng/cm 2 of cobalt, respectively. The selected analytical parameters obtained from the optimization experiments are summarized in Table 2. ...
A new spectrophotometric reagent, N,N'-bis(salicylidene)-ethylenediamine (Salen), has
been synthesized and characterized through novel reaction techniques. A very simple,
ultrasensitive, and nonextractive spectrophotometric method has been developed for the
determination of the picotrace amount of cobalt (II) using Salen. Salen undergoes a reaction in a slightly acidic solution (0.001-0.003 M H2S04) with cobalt in 20% ethanol to give a light
orange chelate, which has an absorption maximum at 459 nm. The reaction is instantaneous,and the absorbance remains stable for over 24 hours. The average molar absorption co�efficient and Sandell’s sensitivity were found to be 6.04×105 L/mol.cm and 5.0 ng/cm2 of Co, respectively. Linear calibration graphs were obtained for 0.001-40 mg/L of Co with adetection limit of 0.1 µg/L and RSD of 0-2 %. The stoichiometric composition of the chelate is 1:1 (Co:Salen). A large excess of over 60 cations, anions and some common complexing agents such as chloride, azide, tartrate, EDTA, SCN-etc. do not interfere in the determination. The developed method was successfully used in the determination of cobalt in several Certified Reference Materials (Alloys, steel, bovine liver, human hair, drinking water, sewage sludge, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, and milk), soil samples, food samples (Vegetables, rice, and wheat) and pharmaceutical samples and solutions containing both cobalt (II) and cobalt (III) as well as complex synthetic mixtures. The results of the proposed method for assessing biological, soil, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).
... Of the five calibration graphs, one showing the limit of the linearity is given in Figure 2. The other four were straight-line graphs passing through the origin (R 2 = 0.9993). The molar absorption co-efficient and the Sandell's sensitivity [33] were found to be 6.04×10 5 L/mol.cm and 5.0 ng/cm 2 of cobalt, respectively. The selected analytical parameters obtained from the optimization experiments are summarized in Table 2. ...
A new spectrophotometric reagent, N,N'-bis(salicylidene)-ethylenediamine (Salen), has been synthesized and characterized through novel reaction techniques. A very simple, ultrasensitive, and nonextractive spectrophotometric method has been developed for the determination of the picotrace amount of cobalt (II) using Salen. Salen undergoes a reaction in a slightly acidic solution (0.001-0.003 M H2S04) with cobalt in 20% ethanol to give a light orange chelate, which has an absorption maximum at 459 nm. The reaction is instantaneous, and the absorbance remains stable for over 24 hours. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 6.04×105 L/mol.cm and 5.0 ng/cm2 of Co, respectively. Linear calibration graphs were obtained for 0.001-40 mg/Lof Co with a detection limit of 0.1 µg/L and RSD of 0-2 %. The stoichiometric composition of the chelate is 1:1 (Co:Salen). A large excess of over 60 cations, anions and some common complexing agents such as chloride, azide, tartrate, EDTA, SCN- etc. do not interfere in the determination. The developed method was successfully used in the determination of cobalt in several Certified Reference Materials (Alloys, steel, bovine liver, human hair, drinking water, sewage sludge, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, and milk), soil samples, food samples (Vegetables, rice, and wheat) and pharmaceutical samples and solutions containing both cobalt (II) and cobalt (III) as well as complex synthetic mixtures. The results of the proposed method for assessing biological, soil, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).
... From the slope of the calibration graph, the average molar absorption co-efficient was found to be 1.6 x 10 5 L mol -1 cm -1 . The Sandell's sensitivity [25] (concentration for 0.001 absorbance unit) was found to be 12 ng cm -2 . Of these two calibration graphs, the one showing the limit of the linearity range is given in (Fig. 6). ...
The very sensitive, fairly selective direct spectrophotometric method is presented for the rapid determination of silver at ultra-trace level using1, 5-diphenylthiocarbazone (dithizone) as a new micellar spectrophotometric reagent ( max = 495 nm) in a slightly acidic (0.1-1.0 M H 2 SO 4) aqueous solution. The presence of a micellar system avoids the previous steps of solvent extraction and reduces the cost, toxicity while enhancing the sensitivity, selectivity and molar absorptivity. The average molar absorptive of the Ag-dithionate complex formed in presence of anionic sodium deducible sulfate (SDS) surfactant was found to be 1.6 x 10 5 L. mol.-1 cm-1 which was almost 10 times higher than the value observed (1.0 x 10 4 L. mol.-1 cm-1) in the standard method, resulting in an increase in the sensitivity of the method. The reaction is instantaneous and the absorbance remains stable for over 24 h. The Sandell's sensitivity was found to 12 ng cm-2 of Ag. Linear calibration graphs were obtained for 0.07-10 mg L-1 of silver; the stoichiometric composition of the chelate is 1:1 (Ag: dithizone). The method is characterized by a detection limit of 0.1 µg L-1 of Ag. Large excess of over 50 cations, anions and complexing agents (e.g. EDTA, tartrate, oxalate, citrate, phosphate, azide) do not interfere in the determination. The method was successfully applied to a number of 469 environmental water samples (potable and polluted), biological samples (human blood and urine), photographical samples and soil samples. The method has high precision and accuracy (s = ±0.01 for 0.1 mg L-1).
... Microorganism concentration was measured at 360 nm using a calibration curve relating the wet weight of the biomass to the dry weight of the biomass at 25°C. Residual metal concentrations were measured at 460 nm and 340 nm for Cu(II) and Ni(II), respectively by using Sodium diethyldithiocarbamate as the complexing agent (Sandell, 1950). ...
It has been suggested that the chelating agent 2-(2-(1-thiophene-2-yl) ethylidene) hydrazinyl) benzoic acid (TEHBA) be utilized to extract, separate and measure platinum(IV) by UV–visible spectrophotometry at the microgram level. Following 5 min of heating the reaction mixture in a water bath, Pt(IV)-TEHBA complex formed. This complex was formed in the presence of potassium iodide solution with a molar absorption coefficient 1.9 × 103 dm3 mol−1 cm−1. At 420 nm, the substance exhibited the greatest absorption. As Beer’s law described, the Pt(IV)-TEHBA complex for platinum(IV) has a beer’s range of 10–50 μg cm−3. It was determined that the proportion ratio of the Pt(IV)-TEHBA complex was 1:1 after its extraction. Despite the investigation of interference from various ions, it was ascertained that the method exhibited selectivity exclusively towards platinum(IV). The trace amounts of platinum(IV) were extracted and quantified from synthetic mixtures representing alloys, binaries and ternary synthetic mixtures. The process of extracting platinum(IV) from pharmaceutical samples involves the implementation of a specific method. Moreover, the procedure exhibits a progressive segregation of palladium(II), platinum(IV) and nickel(II) while also boasting its ease of operation.
In this study, we developed a simple method that enables iron(III) in environmental water to be directly determined via spectrophotometry. In water samples, iron(III) formed a yellowish complex with N-1-Naphthylethylenediamine dihydrochloride (NEDA) at pH 2.0–2.8, the maximum absorption wavelength of which was 462 nm. Detection sensitivity increased in the presence of chloride ions and remained constant for 2–24 h with 0.05–0.57 mol L−1 chloride. Therefore, NEDA solution containing chloride ions was used as a chromogenic reagent for the determination of iron(III). The determination range for this method was 0.1–20 mgFe(III) L−1 in a 5 cm glass cell. The developed method is highly selective for iron(III) and has been successfully applied to freshwater, brackish water, seawater, turbid water in rivers, as well as to riverbed and freshwater lake sediments. In addition, a combination of the proposed NEDA method and the 1,10-phenanthroline method enabled simultaneous determination of iron(III) and iron(II).
The main objective of this research project is to perform some experimental procedures to study the ability of the novel adsorbent used in this project. The chemical modification of the adsorbent is the chemical oxidation of pure powder chitosan using some specific redox pairs which are potassium dichromate and sodium bisulphite. After preparing the modified chitosan, there are some parameters that must be discussed during the adsorption process. The first parameter is the time parameter, showing experimentally the optimum time for adsorption under certain conditions by collecting values of absorbance and concentration of thymol blue adsorbed after the process from the spectrophotometer showing that the optimum time is 120 minutes. While for the optimum pH experiment, it is shown that optimum pH is 4, 0.5% v/v is optimum concentration and 0.05 grams is the optimum dose for the adsorbent. Then after computing these conditions and values of absorbance, some mathematical calculations and classifications are done to show the reaction kinetics classification of the process. By performing some equations using mathematical rules it is provided that the reaction is not a first order reaction, showing by calculations and graphs that the reaction is a second order reaction.
نفذت التجربة في احد البساتين الأهلية بمنطقة الهارثة شمال محافظة البصرة خلال موسم النمو 2015، واســتعملت أشجار السدر صنف تفاحي بعمر 10 سنوات لدراسة تأثير رش الأشجار بالمحـــلول المغذي (مارفل) تركـــــيز (0، 4، 8) مل.لتر-1 وحامض الســــــالســـليك تركيز (0، 50، 100، 150) ملغم.لتر-1 وبواقع رشتين بين رشة وأخر شهر والتداخل بينهما في بعض الصفات الزهرية والكيميائية لأشجار السدر. بينت النتائج أن المعاملة بالمحلول المغذي (مارفل) تركيز 8 مل.لتر أدى إلى زيادة معنوية في جميع الصفات الزهرية ومنها طول الفرع الزهري و عدد النورات الزهرية اذ بلغت 65.61سم و 32.92 بالتتابع، والكلوروفيل 3.16 ملغم.100غم ومحتوى الأوراق في العناصر (النتروجين، الفسفور، البوتاسيوم والحديد) اذ بلغ 3.95% و 0.14% و 1.73% و62.3 بالتتابع . كما أظهرت النتائج أن الرش الورقي بحامض السالسليك تركيز 150 ملغم.لتر أدى إلى زيادة معنوية في جميع الصفات الزهرية والكيميائية المدروسة. وكان للتداخل بين معاملات الرش بالمحلول المغذي وحامض السالسليك تأثير معنوي بتفوق الأشجار المعاملة بالمحلول المغذي تركيز 8 مل.لتر وحامض السالسليك تركيز 150ملغم.لتر في جميع الصفات المدروسة.
Vehicular Pollution is one of the major culprits in environmental degradation. With rapid urbanization and industrialization of the country, indiscriminate fall out of exhaust sources have ensured suffering of plant life-sustaining system. There has been long-established use of "green belt" i.e. plants in preventing pollution thereby protecting the urban environment from industrial pollution. Since plants are the initial acceptors of pollutants, the effects of many airborne particulates from the atmosphere on them cannot be underestimated. This paper assesses the relative sensitivity of four cereal plants: Wheat, Rice, Maize, and Oat that are socioeconomically important plants. The survey is carried out at one of the busiest polluted roads in district Saharanpur of Western Uttar Pradesh in India. The samples of four cereal plants of family Poaceae were collected from the roadside i.e. (20-meter distance away from the roadside equal to the experimental and also away from the roadside i.e. 200-meter distance away from the roadside equal to the control) at three different stages of growth viz. vegetative stage, flowering stage and at yield stage growing under ambient conditions at the selected sites. For each analysis, a few individual plants of similar age groups having equal height were selected at each site and then dried. Thereafter, various parts were individually mixed, dried, and powdered. This powered material was used for the analysis of nitrogen and phosphorous content affecting the plants.
well Scientific Summary-N-PhenylcinnanaJhydroxamic acid (PCHA) reacts with vanadium(V) to form a 1:2 (V:PCHA) bluish-violet coloured complex, quantitatively extractable into chloroform from 3-9 M hydrochloric acid solutions. The spectrum of the complex in the visible region exhibited a broad absorption maximum at 545 nm with a molar absorptivity of 6300 M· I ern I. The coloured system obeyed Beer's law in the concentration range of 0.5-10 ug ml· 1 of vanadium. The effects of several experimental variables on the extraction of the complex have been studied to establish the optimum conditions for the determination of vanadium(V). On the basis of these studies a simple, precise, and sensitive method has been developed for the spectrophotometric determination of vanadium(V). The method has been successfully applied to the determination of vanadium in standard steels. Riassunto-L'acido N-fenilcinnamoidrossamico (PCHA) forma con il vanadio(V) un complesso 1:2 (V:PCHA) colorato in blu-violetto ed estraibile quantitativarrente in cloroformio, da soluzioni 3-9 M di HCL Lo spettro del complesso presenta nella regione del visibile un massimo di assorbimento a 545 nm con un 'assorbivita molare di 6300 M· I crn'. La legge di Beer e seguita in un intervallo di concentrazione di 0.5-10 ug rnl" di vanadio(V), Le condizioni ottirnali per la deterrninazione del vanadio so no state determinate studiando I'effetto di numerose variabili sperimentali sull'estrazione del complesso. II metodo sviluppato, sernplice, preciso e sensibile, e stato applicato con successo alia determinazione del vanadio in campioni di acciai standard.
In the present experimental investigations, a novel reagent 2, 4-dimethyl -3H- 1, 5 benzodiazepine (DBA) has been developed for the extractive estimation of rhodium (III) from given sample and by use of extractive spectrophotometric analysis. In the Laboratory, the fresh reagent was prepared and its characterization has been done with the help of mass spectrophotometer and IR, NMR, elemental analysis. The developed analytical reagent (DBA) when reacts with rhodium (III) produces red complex, this complex can be extracted by using n-butanol as a selected solvent, maintained at constant pH 8.9. The Beers law is followed in the concentration of 1-10 μg L-1 of rhodium (III), the optimum values of maximum absorption, molar extinction coefficient and sandell’s sensitivity to the red complex, observed to be 510 nm, 4863 Lit mol-1cm-2 and 0.01102μg cm-2.The proposed analytical reagent is found to be best, simple and superiorfor extraction of rhodium (III) metals from syntheticsamples at optimized conditions.
Cylindrospermopsin (CYN) is a potent cyanobacterial toxin found in freshwaters worldwide. In this work, the feasibility of the photo-Fenton process under neutral pH using light emitting diodes as irradiation source for the removal of this hazardous cyanotoxin from freshwater was investigated. The impact of the kind of iron chelating agent (ethylenediamine-N, N′-disuccinic acid vs. ethylenedinitrilotetraacetic acid) as well as the effect of the main operating conditions viz. H2O2 dose, Fe(III) load, initial CYN concentration, and Fe(III):EDDS molar ratio on the performance of the process was systematically evaluated. EDDS was selected as the most appropriate iron chelating agent considering the kinetics of the process and the environmental impact (Vibrio fischeri and Artemia salina). Under optimized conditions ([H2O2] = 30 mg L⁻¹; [Fe(III)] = 5 mg L⁻¹; Fe(III):ligand = 1:0.5 (molar ratio)), complete removal of CYN was achieved in 15-min reaction time. Furthermore, the catalytic system showed to be effective in real water matrices (river and reservoir waters) spiked with CYN. Although the presence of inorganic ions (mainly HCO3⁻/CO3²⁻) and dissolved organic carbon decreased the oxidation rate of CYN due to scavenging reactions and iron coordination, respectively, complete elimination of the cyanotoxin was achieved in all cases. The fate of EDDS along the process was also evaluated to demonstrate that the catalytic system investigated, apart from its effectiveness, warrants the complete absence of residues after reaction. Therefore, the proposed system constitutes a promising method for cyanotoxin treatment either as a drinking water treatment step in conventional plants or as a potential remediation strategy in the natural environment.
Young shoots on field-grown trees [ Citrus sinensis , (L.) Osbeck] were the source of repeated chlorophyll measurements on individual leaves by light absorbance and occasional leaf samples for laboratory measurement of chlorophyll and Fe. These concentrations increased or decreased during the period of leaf expansion, depending on comparative rates of Fe uptake, chlorophyll formation, and leaf growth. Chlorophyll/Fe ratio in spring cycle leaves increased until leaves were fully expanded (May—June) and maintained the same level in December. Fall cycle leaves reached the same ratio in December. Linear regression of chlorophyll concentration on Fe concentrations was r = 0.907 at n = 46 for mature leaves having < 50 ppm Fe. Mature leaves having > 50 ppm Fe had essentially equal chlorophyll concentrations, indicating a maximum value of about 3 mg/g F.Wt. A graph of loci for immature leaves showed the majority with low chlorophyll in relation to Fe concentration. It is concluded that the maximum concentration of chlorophyll per unit of Fe is not achieved until leaf maturity.
Un metal como el zinc, constituyente habitual de los ambientes marinos y
estuarinos, cuando es introducido en cantidades adicionales asociado a los desechos
industriales o aguas residuales trae alteraciones en los ciclos biogeoquímicos. Su
potencial toxicidad puede interferir en la ecología de un entorno particular. En una
ensenada contaminada con aguas negras y residuales industriales fueron registradas
concentraciones de zinc iónico comprendidos entre 5.0 y 33.2 mg/L. Durante el
periodo de muestreo se evidenció un proceso de desorción de Zn ++ a partir de la zona
más contaminada, así como una definición neta entre la capa del fondo y el estrato
superficial. Se observa en este último las mayores concentraciones del elemento. Se
analizan, además, las relaciones entre este elemento (Zn) con algunos factores
hidroquímicos, biológicos y ambientales.
The present study was conducted during (2017-2018 and 2018-2019) seasons, at the Hort. Dept., Fac., of. Agric., Benha Univ., Egypt to study the effect of chemical fertilizers (NPK) as a full dose and biofertilization (Bio.) consisting of a mixture of (Nitrobein + Phosphorein) in the presence of Salicylic acid (SA) foliar spray at 150 ppm in a single or combinations inbetween them on vegetative growth ,grain yield ,chemical constituents parameters and oil productivity of coriander plants comparison with control plants in both seasons. The results indicated that different treatments of NPK mineral fertilizer, biofertilization and salicylic acid treatments , either alone or mixed among them, resulted in a significant increase in the growth ,chemical constituents parameters and oil productivity in both seasons. The use of 100% NPK achieved the highest results in the characteristics of growth, yield and chemical composition, followed by the use of the treatment of 75%NPK +Bio.+SA, where it achieved a significant maximize in this concern,whereas the treatment of 75% NPK + Bio. ranked the third in this context as compared with untreated plants in both seasons. Also, the combined treatment of 75% NPK + Bio. + SA gave the highest values of oil productivity. Consequently, in order to achieve the highest values of growth and chemical constituents ,it is preferable to treate coriander with NPK at 100% or 75%NPK + Bio. + SA. Also, it is possible to treat coriander plant with 75% dose NPK +Bio. + SA to improve oil productivity.
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