Determination of copper and iron in biological samples of viral hepatitis (A-E) female patients.

There is accumulative evidence that the metabolism of iron and copper is altered in viral hepatic diseases, and these nutrients might have specific roles in their pathogenesis and progress. The aim of present study was to compare the level of copper (Cu) and iron (Fe) in biological samples (serum, urine, and scalp hair) of female patients suffering from different viral hepatitis (A, B, C, D, and E; n = 253) of age range 31-45 years. For comparative study, 95 healthy females of the same age group residing in the same city were selected. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in sera and scalp hair samples of hepatitis patients than age-matched control subjects, while the difference was significant (p < 0.001), in the cases of viral hepatitis B and viral hepatitis C as compared to viral hepatitis A, D, and E. The urinary levels of these elements were found higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). These results are consistent with literature-reported data, confirming that hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.

Evaluation of an ultrasonic acid digestion procedure for total heavy metals determination in environmental and biological samples.

In this study, a sample preparation method based on ultrasonic assisted acid digestion (UAD) has been evaluated for total heavy metals (Cd, Cr, Ni and Pb) determination in different environmental (soil, sediment and sewage sludge), and biological (fish muscles, vegetables and grains) samples, using electrothermal atomic absorption spectrometry (ETAAS). The investigated parameters influencing UAD such as presonication time, sonication time, temperature of ultrasonic bath, and different acid mixtures were fully optimized, whereas power was maintained constant at 100% of nominal power of ultrasonic bath. Six different sets of above parameters were applied on six certified reference materials (CRMs) having different matrices. The accuracy of the method was also tested by comparing the results with those obtained from conventional hot plate assisted acid digestion method on same CRMs. Analytical results for HMs by both methods showed no significant difference at 95% confidence limit (p<0.05). Recoveries of HMs ranging from 96.2% to 102% and 96.3% to 98.6% were obtained from biological and environmental samples, respectively. The average relative standard deviation of UAD method varied between 3.5% and 8.2%, depending on the analyte.

Estimation of toxic metals in scalp hair samples of chronic kidney patients.

The determination of toxic metals (TMs) in the biological samples of human beings is an important clinical screening procedure. The aim of this work is to determine total content of TMs, aluminum (Al), cadmium (Cd), nickel (Ni), and lead (Pb) in scalp hair samples of chronic kidney male patients (CKPs) on maintenance hemodialysis, during the period of 2005-2007. The study included 115 CKPs (all smokers) and 150 controls or referents [82 (nonsmokers) and 68 (smokers)]. Both controls and patients (males) were of the same age group (ranged 25-55 years), socioeconomic status, localities, and dietary habits. The scalp hair samples were analyzed by electrothermal atomic absorption spectrometer, prior to microwave-induced acid digestion. The accuracy of the total Al, Cd, Ni, and Pb measurements was tested by simultaneously analyzing certified reference material (human hair NCS ZC81002). No significant differences were observed between the analytical results and the certified values (paired t test at p > 0.05). The levels of TMs in scalp hair samples of patients were found to be higher as compared to control nonsmoker and smokers. Moreover, the study shows that levels of Al, Cd, Ni, and Pb in scalp hair samples may be useful to evaluate the impact of cigarette smoking in kidney failure patients.

Improved extraction method for the determination of iron, copper, and nickel in new varieties of sunflower oil by atomic absorption spectroscopy.

A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.8-97.5, 93.5-98.3, and 95.6-98.2%, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health.

Hazardous impact of toxic metals on tobacco leaves grown in contaminated soil by ultrasonic assisted pseudo-digestion: multivariate study.

Tobacco leaves (Nicotiana tabacum L.), agricultural soil and pollute irrigated lake water samples were collected during 2005--2006 and analyzed for Cd and Ni by electrothermal atomic absorption spectrometry (ETAAS). A simple and efficient procedure was investigated for the complete decomposition of tobacco leaves using ultrasonic assisted acid pseudo-digestion method (UPDM). A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of seven factors/variables at once, while central composite were used to found optimum values of significant variables. The accuracy of the proposed methods was assessed by analyzing certified reference (CRM); Virginia tobacco leaves (CTA-VTL-2). The results being compared with those obtained by conventional wet acid digestion method. The result obtained by optimized method showed good agreement with the certified values and sufficiently high recovery 97.8 and 98.7% for Cd and Ni, respectively. Under optimal conditions, the detection limits (3sigma) were evaluated to be 0.019 microg g(-1) for Cd and 0.37 microg g(-1) for Ni. The proposed method was successfully applied to the determination of Cd and Ni in raw, processed tobacco and different branded cigarettes samples.

Distribution of zinc, copper and iron in biological samples of Pakistani myocardial infarction (1st, 2nd and 3rd heart attack) patients and controls.

BACKGROUND: The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. We examined the association of iron, copper and zinc between biological samples (scalp hair, whole blood and urine) and mortality from myocardial infarction (MI) patients of (first, second and third heart attack). METHODS: The biological samples were from 130 MI patients (77 male and 53 female, age range 45-60 years) and 61 healthy age-matched controls (33 male and 28 female). The metals in the biological samples were measured by the flame atomic absorption spectrophotometry, prior to microwave assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. RESULTS: During this study, 78% of the 32 patients aged >50 years, registered after the third MI attack died. In these subjects the concentration of Fe and Cu were increased by 0.83% and 3.12% in the scalp hair while in blood samples 9.7% and 22.5% were enhanced respectively, as compared to those who tolerated 3rd MI attack (p=0.072). The concentrations of Zn in whole blood and scalp hair samples were lower in MI patients as compared to normal subjects. CONCLUSION: Deficiency of zinc and high concentration of copper and iron may play a role in the development of heart disease.

Application of fractional factorial design and Doehlert matrix in the optimization of experimental variables associated with the ultrasonic-assisted acid digestion of chocolate samples for aluminum determination by atomic absorption spectrometry.

A simple and rapid method based on ultrasound energy is described for the determination of aluminum (AI) in complex matrixes of chocolate and candy samples by electrothermal atomic absorption spectrometry. The optimization strategy was carried out using multivariate methodologies. Five variables (temperature of the ultrasonic bath; exposure time to ultrasound energy; volumes of 2 acid mixtures, HNO3-H2SO4-H2O2 (1 + 1 + 1) and HNO3-H2O2 (1 + 1); and sample mass) were considered as factors in the optimization process. Interactions between analytical factors and their optimal levels were investigated using fractional factorial and Doehlert matrix designs. Validation of the ultrasonic-assisted acid digestion procedure was performed against standard reference materials, milk powder (SRM 8435) and wheat flour (SRM 1567a). The proposed procedure allowed Al determination with a detection limit of 2.3 microg/L (signal-to-noise = 3) and a precision, calculated as relative standard deviation, of 2.2% for a set of 10 measurements of certified samples. The recovery of Al by the proposed procedure was close to 100%, and no significant difference at the 95% confidence level was found between determined and certified values of Al. The proposed procedure was applied to the determination of Al in chocolate and candy samples. The results indicated that cocoa-based chocolates have higher contents of Al than milk- and sugar-based chocolates and candies.