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A simple and sensitive flow-injection method is reported for the determination of retinol and α-tocopherol in human blood serum and pharmaceuticals. The method is based on the reduction of vanadium(V) by retinol and α-tocopherol and subsequent reaction of reduced vanadium with luminol to generate chemiluminescence signal. The optimized conditions a...
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... before they can establish a chain reaction. No obvious unique function for vitamin E has been defined. How- ever, it does act as a lipid-soluble antioxidant in cell membranes, where many of its functions can be provided by synthetic antioxidants (Combs 2008;Murray et al. 2003). The chemical structures of retinol and a-tocopherol are given in Fig. ...
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... of 1-3.5 mL min À1 , and a flow rate of 2.25 mL min À1 gave the maximum CL response with a steady baseline and repro- ducible peak heights (Fig. 9). Using an optimum flow rate of 2.25 mL min À1 , the effect of sample injection volume was investigated over the range of 60-420 mL, and a 300 mL gave the highest CL signal and was used subsequently (Fig. ...
Citations
... In flow-mode, DPA coupled with luminol CL reaction has many applications for the determination of different analytes in several samples (21,24). Several flow injection-CL (FI-CL) and FI-UV/Vis-spectrophotometric methods have been described in the literature for the quantitative measurements of VA (retinol) in different matrices (12,13,(25)(26)(27)(28)(29)(30)(31). The analytical figures of merit, optimum experimental parameters and their applications for all these methods have been described in Table 1. ...
... Table 1 reports the comparison of analytical performance of the proposed method with previously reported methods for the assay of VA in different matrices. Among FI-CL methods reported in the literature (25)(26)(27)(28)(29)(30)(31), the proposed method has low detection limit, wide linearity and high injection throughput except lucigenin-Brij-35-CL (27), tris(2,2′-bipyridyl)Ru(II)-Ce(IV)-CL (25) and Ce(IV)-Na2SO3-CL (29) methods respectively and in most of these methods, high concentration of CL reagents and PMT voltage have been employed comparatively. ...
In this paper, a chemiluminescence (CL) method is proposed for retinol determination by combining flow injection (FI) methodology. The CL reaction is based on the oxidation of luminol by diperiodatoargentate(III) (DPA) in the presence of retinol. Under the optimum conditions, the relative CL intensity was linear to the concentration of reti-nol over the range 5.0310 23-14 mg L 21 (y5347.26x12.5944, R 2 50.9999, n58) with limit of detection (LOD) of 1.5310 23 mg L 21 (S/N53) and limit of quantification (LOQ) of 5.0310 23 mg L 21 (S/N510). The relative standard deviation (RSD) was from 1.04-3.4% over the range studied and injection throughputs of 150 h 21. The method was satisfactorily applied to retinol in pharmaceutical formulation samples. The samples were saponified and extracted with liquid-liquid extraction using ether as an extractant. The possible CL mechanism is supported by CL and UV-visible spectrophotometric studies.
... The literature describes many methods for determination of vitamins in food, pharmaceutical, and physiological samples, including spectrophotometry, chemiluminescence, fluorimetry, capillary zone electrophoresis, and chromatography (Amin 2001;Waseem and Nabi 2011;Ibrahim, Hassan, and Hefnawy 1991;Razagui, Barlow, and Taylor 1992;Rishi et al. 2009;Jadoon et al. 2010). The use of chromatography is preferred when samples have significant concentrations of potential interferents that may include other vitamins, minerals, proteins, and sugars. ...
A novel method was developed for the simultaneous electrochemical determination of α-tocopherol (viatmin E) and retinol (vitamin A) using a poly(2,2′-(1,4-phenylenedivinylene)-bis-8-hydroxyquinaldine)/multiwalled carbon nanotube modified glassy carbon electrode. The simple and rapid voltammetric approach was evaluated for real samples using Triton X-100 to solubilize the analytes in the absence of organic solvent. The calibration graph for α-tocopherol was linear from 8 to 100 µM with a limit of detection of 0.1 µM in the presence of 80 µM retinol. The response was also linear with retinol concentration from 5 to 200 µM with a detection limit of 0.8 µM in the presence of 40 µM α-tocopherol. The developed method was employed for the determination of the vitamins in pharmaceutical products.
... Transition metal ions (Co 2+ , Cu 2+ , Fe 3+ , etc.) are used as a typical catalyst for luminol CL reactions [5]. Different analytical techniques have been reported in literature for the determination of vitamin A (most often retinol) in diverse samples including flow injection spectrophotometry [6], chemiluminescence [7][8][9][10], and HPLC [11][12][13]. Few flow injection chemiluminescence methods are reported for the determination of vitamin C in pharmaceuticals, urine, and blood serum [14][15][16]. ...
Rose Bengal photosensitized flow injection chemiluminescence method is reported using luminol-Cu(II) for the determination of vitamins A and C in pharmaceutical formulations. The reaction is based on the enhancement effect of analyte in the production of anion radicals of Rose Bengal (RB (•-)) which rapidly interact with dissolved oxygen and generate superoxide anions radicals (O2 (•-)) and hydrogen peroxide (H2O2). Highly reactive hydroxyl radicals ( (•) OH) were produced via dismutation of H2O2 by catalyst (Cu(2+)). The generated superoxide anions radicals and hydroxyl radicals thus oxidize luminol in alkaline medium to generate strong chemiluminescence. The limit of detection (3s of the blank, n = 6) of vitamins A and C and RB was found to be 0.008, 0.005, and 0.05 μg mL(-1), respectively. The sample throughput of 70 h(-1) for vitamins A and C and 30 h(-1) for RB was found. Calibration curve was linear in the range of 0.05-15, 0.01-20, and 0.1-50 μg mL(-1) for vitamins A and C and RB, respectively, with relative standard deviations (RSDs; n = 3) in the range 1.6-3.6%. The method was successfully applied to pharmaceutical formulations and the results obtained were in good agreement with the labeled values.
... Luminol CL reaction is catalysed by a number of metal ions like Cu(II) [75,76], Co(II) [77], V(IV) [78], and AgNPs [79][80][81], Au NPs [82], CdTeNPs [83] and Pt colloids [40] for the determination of antibiotics, vitamins, amino acids, sugars etc [75][76][77][78][79][80][81][82]. The complexes of Fe(III)/(II) (K 3 [Fe(CN) 6 ] and K 4 [Fe(CN) 6 ]) was found to act as catalysts for luminol CL reactions. ...
... Luminol CL reaction is catalysed by a number of metal ions like Cu(II) [75,76], Co(II) [77], V(IV) [78], and AgNPs [79][80][81], Au NPs [82], CdTeNPs [83] and Pt colloids [40] for the determination of antibiotics, vitamins, amino acids, sugars etc [75][76][77][78][79][80][81][82]. The complexes of Fe(III)/(II) (K 3 [Fe(CN) 6 ] and K 4 [Fe(CN) 6 ]) was found to act as catalysts for luminol CL reactions. ...
In this article we present an update on the applications of chemiluminescence coupled with flow injection analysis for the determination of pharmaceuticals. Several reported applications of flow and sequential injection chemiluminescence (FI-CL/SI-CL) in pharmaceuticals concern greatly on quality control, investigation of dissolution of particular formulations or process control of production of pharmaceuticals and their presence in physiological fluids. A number of advances in the development of FI-CL methods have been reported in recent years on pharmaceutical analysis. In the present review we have covered six years period from Jan-2007 to Dec-2012 discussing FI-CL/SI-CL in the liquid phase as an analytical tool for the determination of pharmaceuticals in diverse samples. We reviewed the methods as per general CL reaction involved with the help of 321 cited references. Interesting features of the FI-CL methods like the use of molecularly imprinting polymers for selectively and specially designed cells/microfluidic devices or lab-on-a-chip for better detection or sensitivity were also presented.
... Advantages of using FIA are: increased sample injections throughputs, high versatility, high robustness, decrease of the human exposure under hazardous chemical/physical sample pre-treatments. Due to these advantages, FIA has been coupled with UV-Vis, fluorescence and chemiluminescence detectors for the detection of wide variety of analytes (Rishi et al., 2011;Asgher et al., 2011;Attiq-ur-Rehman et al., 2008Waseem et al., 2007Waseem et al., , 2008Yaqoob et al., 2001). The aim of this study design under discussion is to establish a rapid, direct, easy and equally sensitive, accurate and reliable UV/fluorescence spectrophotometric method for the determination of CC. ...
This article describes the development of flow injection methods for the determination of Candesartan Cilexetil using spectrophotometery and spectrofluorimetry in pharmaceutical formulations. The first method is based on the UV absorption at 270 nm in phosphate buffer containing cetyl trimethylammonium bromide (CTAB) and methanol at pH 6.5. The second method based on the fluorescence excitation and emission at 260 and 384 nm respectively, in phosphate buffer containing sodium dodecyl sulphate (SDS) and methanol at pH 4.0. Calibration graphs were linear over the concentration range of 0.1 to 4.0 μg/ml for UV-method and 0.03 to 2.0 μg/ml for fluorescence method. The limits of detection (3 s) of 0.01 μg/ml for both methods with sample throughput of 80 and 100/h were obtained respectively. The relative standard deviations of 1.2 to 3.2% (n = 4) for UV-method and 0.5 to 1.8% for fluorescence method were achieved in the concentration range studied. The developed methods were applied to pharmaceuticals and the results obtained were compared with HPLC reference method and no significant difference between these methods was observed at 95% confidence level. © 2011 Academic Journals.
A simple and rapid flow injection (FI) method for the determination of retinyl acetate is reported based on its enhancing effect on the luminol-periodate chemiluminescence (CL) system in an alkaline medium. The detection limit (3sxblank) was 8.0x10(-8) mol L(-1), with an injection throughput of 90 h(-1). The method allows linear increase of CL intensity over the retinyl acetate concentration range of 1.0-100x10(-7) mol L(-1) (R(2)=0.9996) with relative standard deviations of 2.4% (n=10) for 5.0x10(-7) mol L(-1). The key chemical and physical variables (reagent concentrations, flow rates, sample volume, and photomultiplier tube (PMT) voltage) were optimized and potential interferences were investigated. The method was successfully applied to human milk, fresh cow's milk and infant milk-based formulas and the results were in good agreement with the previously reported HPLC method. A brief discussion on the possible CL reaction mechanism is also presented.
A rapid and simple flow injection (FI) method is reported for the determination of vitamin A (retinol) based on its strong enhancing effect on the Ce(IV)–Na2SO3 chemiluminescence (CL) reaction in an acidic solution. The effect of key chemical and physical parameters (i.e., reagent concentrations, flow rate and sample volume) was optimized and potential interferences examined. Under the selected experimental conditions, a linear calibration was obtained between the CL intensity and vitamin A concentration in the range 0.1 − 8.0 µ g mL (r = 0.9986, n = 8). The limit of detection (3 s x blank) was 0.01 µ g mL retinol (n = 6) and the relative standard deviation (RSD) for 0.25 µ g mL retinol was 2.3% (n = 10) with a sampling rate of 180 h. The method was successfully applied to infant milk-based formulas and pharmaceutical formulations and the results were not significantly different at 95% confidence interval with those obtained by using a spectrophotometric reference method. The possible CL mechanism is also discussed briefly supporting with UV-visible, fluorescence and CL spectra.
The state of the art in flow-chemiluminescence (flow-CL) technique for automated pharmaceutical analysis is reviewed. Flow-CL approaches have become powerful and promising tools for pharmaceutical screening in recent years due to their simplicity, low cost and high sensitivity. Because of these advantages, these methods have been widely used for pharmaceutical analysis in recent years. The literature reviewed covers papers of analytical interest that appeared between 2007 and mid-2012 and have been divided into several sections based on fundamental types of CL systems employed. Furthermore, entries have been summarized alphabetically in tabular form giving details of analytical figures of merit of the methods. Copyright © 2012 John Wiley & Sons, Ltd.
