Content uploaded by George Zachariadis
Author content
All content in this area was uploaded by George Zachariadis on Jun 25, 2014
Content may be subject to copyright.
A preview of the PDF is not available
Critical comparison of wet and dry digestion procedures for trace metal analysis of meat and fish tissues
Abstract and Figures
The efficiency of four methods of digestion was evaluated for trace metal analysis of pork meat and carp fish tissues. Two methods of dry and two methods of wet ashing were compared in terms of calculated variances. Mixtures of HCl+HNO3 were applied for wet ashing of the samples at 100 C, while dry ashing with or without H2SO4 at 450 C were the alternative methods. The digests were subsequently analysed for Pb, Cd, Cu and Zn by graphite furnace atomic absorption spectrometry. Analysis of variance and Student's t-test were performed separately for meat and fish analytical results. Wet digestion with a (1+1) mixture of HCl+HNO3 has given better recovery and repeatability for almost all metals than a (9+1) mixture of HCl+HNO3. Also between the dry ashing methods, the use of H2SO4 has given better results than ashing of the tissues without H2SO4.
Figures - uploaded by George Zachariadis
Author content
All figure content in this area was uploaded by George Zachariadis
Content may be subject to copyright.
... Analysis of phosphorus concentration in fish feed and fish meat was carried out by wet digestion method (Zachariadis et al 1995) using sulfuric acid (H2SO4). 5 g of feed and fish meat samples were used. ...
... The Pb concentration was measured in the cortical tissue using the method described by Zachariadis et al. (1995) and Manoj Kumar et al. (2017). Briefly, pieces of cortical tissue were dried in an oven at 60 °C for 24 h, then combusted at 150 °C. ...
... The Pb concentration was measured in the cortical tissue using the method described by Zachariadis et al. (1995) and Manoj Kumar et al. (2017). Briefly, pieces of cortical tissue were dried in an oven at 60 °C for 24 h, then combusted at 150 °C. ...
Lead (Pb) is a known toxic heavy metal which accumulates in different tissues and causes oxidative stress (OS) and inflammation. The brain tissue is considered as one of the most vulnerable organs to the Pb-induced toxicity. The aim of this study was to investigate the therapeutic effects of vitamin D3 (VD) supplementation against the damages caused by chronic Pb toxicity in the cerebral cortex. Forty Wistar rats were divided into four equal groups and were treated as follows: control group received no treatment, VD group received 1000 IU/kg of VD by intramuscular injection every other day, Pb group received 1000 mg/L of Pb in drinking water, and Pb + VD group received VD and Pb simultaneously. The experiment lasted for 4 weeks and the analyses were conducted 24 h after the last administrations. The obtained results demonstrated that Pb significantly increased cortical lipid peroxidation and reactive oxygen species (ROS) levels. At the same time, there was a significant reduction in glutathione (GSH) content, catalase (CAT), and superoxide dismutase (SOD) activities, as well as a significant increase in the tissue level of inflammatory cytokines. Furthermore, Pb increased the messenger RNA (mRNA) expression level of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB). Anyhow, VD administration during the period of Pb exposure suppressed the OS and inflammation by increasing the antioxidant molecules and decreasing the inflammatory cytokines and consequently repaired Pb-induced cortical tissue damages. Remarkably, these responses were concomitant with the alterations in Nrf2 and NF-κB gene expressions. In conclusion, the present study discloses the potential protective effects for VD against Pb-induced neurotoxicity via anti-inflammatory and antioxidative mechanisms.
... Wet ashing, dry ashing, and microwave digestion are among the most usual methods for sample decomposition 9,11 . In wet ashing, a mixture of acids with or without oxidants (H 2 O 2 ) was used along with heating in open or closed vessels [11][12] . This method needs constant monitoring and its applicability depends on the type of food 13 . ...
Introduction: In recent years, the contamination of food with heavy metals has received much attention. Plants can absorb metal pollutants through contaminated water, soil, and air.
Materials and Methods: In the current study, accumulation of minerals in three types of soybeans was investigated by wet and dry digestion methods using ICP-OES technique. Thereafter, the metals' health risk was assessed by estimated daily intake, toxic hazard quotient (THQ), and hazard index (HI) values.
Results: According to the results, the concentrations of Cr, Se, Ca, Fe, Mo, Mn, and Mg in soybean seeds were 0.034-170.88 mg/kg, 0.21-243.79 mg//kg, 2.50-33.37 mg/kg, 0.05-0.86 mg/kg, 0.071-203.57 mg/kg, 0-0.47 mg/kg, and 2.69-19.31 mg/kg, respectively. The ashing method had a better performance in determining Ca, Fe, Mo, Mn, and Mg concentrations than the wet digestion method. The THQ rates were below 1 for the three varieties of each mineral element, but the HI values of variety 2 and variety 3 were higher than 1 in both methods.
Conclusion: Furthermore, continuous monitoring of the soybeans' mineral and heavy metal contents seems necessary.
... Moreover, in some cases before digestion, prostate samples are treated with solvents (distilled water, ethanol etc) and then are dried at a high temperature for many hours. Sample pretreatment and digestion is a critical step in elemental analysis, due to risk of contamination and analytes loss, contributing for the uncontrolled analysis errors [79][80][81][82][83][84]. Additionally, only a few of these studies employed quality control using certified reference materials for determination of accuracy and precision of the chemical element mass fraction measurement. ...
Prostate cancer is an internationally important health problem in man, particularly in developed countries.The aim of this exploratory study was to clarify the differences between the prostatic levels of chemical elements in patients with malignantly transformed prostate (PCa) and healthy male inhabitance. Prostatic tissue levels of 66 chemical elements were prospectively evaluated in 60 patients with PCa and 37 healthy males. Measurements were performed using a combination of five non-destructive and destructive analytical methods. A significant increase in the mean level of Ag, Al, Au, B, Ba, Be, Bi, Br, Ce, Cr, Cu, Dy, Er, Fe, Gd, Hg, Ho, Li, Mn, Nd, Ni, Pr, Sb, Si, Sm, Sn, Sr, Tb, Th, Ti, Tl, Tm, Y and Zr accompanied a decrease in the mean level of Ca, Cd, Co, K, Mg, Na, P, Rb, S, Sc, Se, and Zn was observed in the cancerous prostates. It was not found any differences in the mean prostatic level of other chemical elements including Cs, La, Mo, Nb, P, Pb, U, and Yb between PCa patients and healthy males. This work results reveal that in malignantly transformed prostate the chemical element metabolism is drastically disturbed.
... The most frequently used digestion procedures are the traditional dry ashing and high-pressure wet digestion that allow destruction of organic matter of the sample. Sample digestion is a critical step in elemental analysis and due to the risk of contamination and analytes loss contributes to the systematic uncontrolled analysis errors [3,18,21,[47][48][49][50][51]. Therefore, sample-nondestructive technique like EDXRF is good alternatives for multielemental determination in infant formula and milk products. ...
We have developed and validated an energy dispersive X-Ray uorescence (EDXRF) method for the rapid determination of concentrations of key chemical elements (Br, Ca, Cl, Cu, Fe, K, Mg, P, S, Se, and Zn) in milk-based products. To demonstrate the utility of the EDXRF method for the chemical element determination in milk product, concentrations of chemical elements in two infant formulas (infant rst milk and toddler milk) widely marketed in the UK were investigated. The infant rst milk formula was found to have signi cantly high levels of Cu, Fe, Mg, Se and particularly high concentrations of Ca and P, which were nearly six and twenty times higher than the manufacturer’s label declaration, respectively. By contrast, analysis of the chemical elements concentrations in the toddler milk formula was generally close to the values declared by the manufacturer with the exception of Cu and Mg, which were about three and two times higher than declared on the label, respectively. We discuss the obtained results in the light of speci c nutritional needs of infants and data reported in literature.
... The tissue lead concentration was determined by the method of Zachariadis et al. (1995). A known quantity of the wet tissue was kept in muffle furnace at a temperature of 600°C for about 4-5 h to make into ash. ...
The present investigation was undertaken to evaluate the ameliorative activity of Allium sativum against lead-induced oxidative stress in the brain, liver, and kidney of male rats. Four groups of male Wistar strain rats (100-120 g) were taken: group 1 received 1000 mg/L sodium acetate and group 2 was given 1000 mg/L lead acetate through drinking water for 2 weeks. Group 3 and 4 were treated with 250 mg/kg body weight/day of A. sativum and 500 mg/kg body weight/day of A. sativum, respectively, by oral intubation for a period of 2 weeks along with lead acetate. The rats were sacrificed after treatment and the brain, liver, and kidney were isolated on ice. In the brain, four important regions namely the hippocampus, cerebellum, cerebral cortex, and brain stem were separated and used for the present investigation. Blood was also drawn by cardiac puncture and preserved in heparinized vials at 4 °C for estimation of delta-aminolevulinic acid dehydratase (ALAD) activity. The results showed a significant (p < 0.05) increase in reactive oxygen species (ROS), lipid peroxidation products (LPP), total protein carbonyl content (TPCC), and lead in the selected brain regions, liver, and kidney of lead-exposed group compared with their respective controls. Blood delta-ALAD activity showed a significant (p < 0.05) decrease in the lead-exposed rats. However, the concomitant administration of A. sativum resulted in tissue-specific recovery of oxidative stress parameters namely ROS, LPP, and TPCC. A. sativum treatment also restored the blood delta-ALAD activity back to control. Overall, our results indicate that A. sativum administration could be an effective antioxidant treatment strategy for lead-induced oxidative insult.
... The wet digestion methods were generally faster than the dry ashing methods but required the use of large amounts of reagents and, therefore, gave higher blank contributions for some elements (Adeloju, 1989). Some researchers have reported that microwave digestion methods give higher recoveries for many elements in comparison with dry ashing methods (Aydin, 2008;Bakircioglu et al., 2011;Demirel et al., 2008;Guldas, 2008;Kaya et al., 2008;Soylak et al., 2004;Yaman and Cokol, 2004;Zachariadis et al., 1995). However, other researchers have found no significant differences between dry ashing and microwave digestion for the determination of major and trace elements in organic matter (Moreno et al., 2008), pine needles (Vaisanen et al., 2008), plant samples (Masson et al., 2010), and human hair (Dogan and Kaya, 2010;Ming and Bing, 1998). ...
... Moreover, in some cases before digestion, prostate samples are treated with solvents (distilled water, ethanol etc) and then are dried at a high temperature for many hours. Sample pretreatment and digestion is a critical step in elemental analysis, due to risk of contamination and analytes loss, contributing for the uncontrolled analysis errors (Fuente & Juаrez, 1995;Zachariadis et al., 1995;Zaichick, 1997;V. Zaichick & S. Zaichick, 1997;Zaichick, 2004a;Khan et al., 2013). ...
Adenocarcinoma of prostate gland is an internationally important health problem in men, particularly in developed countries. The aim of this exploratory study was to evaluate whether significant changes in the prostatic tissue levels of trace elements exist in the malignantly transformed prostate. Prostatic tissue levels of 43 trace elements were prospectively evaluated in 36 patients with prostate adenocarcinoma and 37 healthy males. Measurements were performed using a combination of non-destructive and destructive methods: instrumental neutron activation analysis and inductively coupled plasma mass spectrometry, respectively. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. The reliability of difference in the results between normal and cancerous prostate tissues was evaluated by Student’s t-test. It was found that the contents of Ag, Al, Au, B, Be, Br, Ce, Cr, Dy, Er, Fe, Gd, Hg, Li, Mn, Nd, Ni, Pr, Sb, Sn, Th, Tl, Y, and Zr were significantly higher while those of Cd, Co, Rb, Sc, Se, and Zn were significantly lower in cancerous tissues than in normal tissues. Moreover, it was shown that malignant transformation significantly changed the relationships of trace elements in prostate. Thus, in adenocarcinoma transformed prostate tissue the trace element metabolism is significantly disturbed.
Levels of cadmium in the environment have drastically increased over the last decades, as a result of human activity. This cadmium pollution is transferred to the human food chain resulting in elevated concentrations in some foods such as vegetables and grain crops, animal liver and kidney and especially seafood. Cadmium ingested by animals and humans, accumulates mainly in the renal cortex and may result in a variety of toxic effects, such as renal damage, bone degeneration and cancer. Taking into account the rather elevated concentrations of cadmium in offal and seafood appearing in the international literature, a continuous control of such products is suggested as necessary in order to protect consumers from any undue exposure to this heavy metal.
We have developed procedures to determine 12 trace elements, Al, As, Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, and V, in natural water using the stabilized temperature platform furnace. Suitable matrix modifiers were tested. Confirmation of the techniques was obtained by recovery experiments at four different concentration levels. Only simple aqueous standards were required and the method of additions was not used. A simple recovery experiment was satisfactory confirmation of freedom from chemical interferences. The detection limits in the natural waters were less than 1 μg/liter, closer to 0.1 μg/liter for most of the elements. The precision was 10 to 15%. The work did not require clean-room facilities.
A comparison is made between a platform-equipped Perkin-Elmer HGA-500 and a recently designed two-step constant-temperature graphite furnace with respect to susceptibility to interference effects as well as attainable detection limits. It is shown that larger quantities of biological samples can be used with the constant-temperature furnace without suppressing the analyte signal, resulting in lower detection limits. Materials studied include NBS Olyster Tissue and Bovine Liver, and human lung tissue and human blood.
A chemical modifier (NH4H2PO4) and a modified L'vov platform are investigated for possible alleviation of matrix interferences, which are normally severe during graphite furnace analysis of fish tissues for lead. Slope ratios of additions plot to standard curve were calculated under four atomization conditions with regular graphite tubes: tube wall, tube + modifier, platform, and platform + modifier. The effects on slope ratios of slow (1 s RAMP) vs. fast (MAX POWER) heating rates during atomization are also investigated. Near unity (1.00) slope ratios were produced with the MAX POWER platform + modifier combination for whole ground fish, fish liver, and fish blood using carefully optimized charring and atomization temperatures based on sample matrix and atomization conditions. Most slope ratio improvement was due to the addition of NH4H2PO4. Precision with the MAX POWER platform + modifier combination was 0.5% relative standard deviation.
A microwave drying oven was evaluated for potential use as an alternate method of sample pretreatment in an analytical laboratory. The high-precision drying data achieved suggests that this instrument is well-suited to industrial applications such as quality control and merits further study. However, differences in conventional drying and microwave drying make the current Implementation of the microwave drying oven unfeasible in a reference laboratory, especially when highly accurate measurements are required on a wide range of materials.
Modern Analytical Chemistry needs not only automatic devices, standard methods and evaluation characterisctics such as error values, selectivity ratios, limits of detection and so on. Analytical Chemistry requires further a highly ordered system for distinct and informative description of these devices, methods and characteristics. We do believe that a symbolic system fulfils entirely these requirements since it contains all necessary parameters of a modern analytical process.
The aim of the present paper is to provoke a cooperative work between analytical chemists, editors, abstracts and authors. The belief of the authors is not sufficient to realize the application of a symbolic system in Analytical Chemistry. Any discussion on the structure and the symbols used in the system SSSAC could lead to a real development of the communication in the field of Analytical Chemistry. In such a way this symbolic system is not only a better communication remedy in Analytical Chemistry but a further step to automation in and with Analytical Chemistry.
The food processor was evaluated as an alternative to the food chopper and bowl cutter for preparing meat samples for analysis in AOAC procedure 24.001. Samples of 6 meat types--cooked sausage, pork sausage, canned ham, hamburger, water-added ham, and smoked ham--were distributed to 9 laboratories for preparation using a food processor. The resulting 54 samples were sent to a USDA-accredited laboratory for analysis in triplicate for moisture, protein, and fat. Standard deviations and their 95% confidence intervals calculated for the analytical results were compared with USDA Performance Standards. With few exceptions, the upper limits were lower than the Performance Standards and for the exceptions, the intervals included the Performance Standards. By these criteria, the food processor is as effective in preparing homogeneous samples as the preparation procedures used to set the Performance Standards. Collaborators found the processor faster to use and easier to clean than the food chopper. Use of the food processor has received interim approval as an alternative to the food chopper or bowl cutter in AOAC procedure 24.001 for preparing meat samples for analysis.
We compared 4 digestion procedures, namely, sulfuric-nitric acid in an open flask, nitric acid under pressure, sulfuric-nitric acid with refluxing, and nitric-hydrochloric-peroxide with refluxing, for the determination of cadmium by flameless atomic absorption spectrophotometry in 3 foodstuffs: rice, beef, and cream cheese. The foodstuffs were homogenized and divided into several batches for analysis. The results were evaluated using a 2-way cross analysis of variance. The study revealed that the digestion procedure was a highly significant factor (P less than 10(-4] in the analysis of the 3 foods; whereas the nature of the foodstuffs was not significant for rice and meat and only slightly significant (P less than 10(-2] for cream cheese. When the foodstuffs were spiked with a known amount of cadmium, we observed a loss of the metal when the sulfuric-nitric acid procedure in an open flask and the nitric-hydrochloric-peroxide digestion procedure were used. Taken together, the results of the present study indicate that the choice of the reagents used for digestion of foodstuffs is a crucial factor for cadmium determination by flameless atomic absorption spectrophotometry.
A simple, automated wet digestion procedure was developed for the quantitative determination by atomic absorption spectroscopy (AAS) of arsenic, cadmium, copper, mercury, lead, selenium, and zinc in animal tissue. A commercial digestion block system with automated temperature programming was used. Recoveries of all elements from spiked bovine liver and kidney samples exceed 95%. The analytical results obtained for samples of NBS Bovine Liver (No. 1577a) agree well with certified values. The procedure is safe and requires minimum analyst time.
A simple and rapid digestion method is reported for the simultaneous acid extraction of chromium, copper, zinc, cadmium, nickel and lead from high-fat fish tissue. Samples are digested with nitric and sulphuric acids at 150 °C in a modified aluminium hot-block. The method is specially set up for fish sample sizes of up to 5 g, for low level detection of these elements. After digestion, acid extracts of the sample are analysed by direct flame atomic-absorption spectrometry for copper, zinc and chromium. The other three elements, cadmium, nickel and lead, are concentrated by chelation with ammonium tetramethylene dithiocarbamate followed by solvent extraction with isobutyl methyl ketone and determined by flame atomic-absorption spectrometry. The ease, rapidity and safety by which samples can be processed by this method make it suitable for the routine preparation of a large number of samples simultaneously.