Orhan Acar

Determination of Heavy Metal Contents in Human Colostrum Samples by Electrothermal Atomic Absorption Spectrophotometry

Determination of lead, cadmium, nickel, chromium, manganese and copper levels in colostrum samples (n = 30), collected from middle-class mothers, was carried out by electrothermal atomic absorption spectrophotometer (ETAAS) with Zeeman effect background correction using a tungsten-palladium-citric acid chemical modifier mixture. A wet-ashing procedure was applied to dissolve the samples and to remove the fat. The graphite furnace temperature programme for analytes determined by ETAAS was studied, and the optimum pyrolysis temperatures of Pb, Cd, Ni, Cr, Mn and Cu were determined in the presence of the modifier mixture. Detection limits of Pb, Cd, Cu, Mn and Cr were determined using a modifier mixture solution. Zinc and iron levels were determined by Zeeman flame atomic absorption spectrometer (F-AAS). Heavy metal levels (mean values) found in colostrum samples were 14.6 microg/l of Pb, 2.8 microg/l of Cd, 27.8 microg/l of Ni, 8.6 microg/l of Cr, 43.2 microg/l of Mn, 278 microg/l of Cu, 12.9 mg/l of Zn, and 3.5 mg/l of Fe. These metal levels were compared with results from other studies in different countries.

Determination of bismuth, indium and lead in geological and sea-water samples by electrothermal atomic absorption spectrometry with nickel-containing chemical modifiers

Abstract The electrothermal atomic absorption spectrometric determination of bismuth, indium and lead in geological samples and synthetic sea water has been carried out by using nickel-containing chemical modifiers. A comprehensive comparison was made among the nickel-containing modifiers such as Ni, Ni+Pd, Ni+Rh, Ni+Pt and Ni+Ru. In addition to that, tartaric acid (TA) was used as a reducing agent together with the above-mentioned mixed modifiers. Comparison was made in terms of pyrolysis temperature, atomization and background absorption signal shapes, and accuracy of the determination. The modifier mixtures of Ni+Pd+TA and Ni+Pt+TA were found to be preferable for the determination of analytes because they increased the pyrolysis temperatures up to 1200–1400°C. Depending on the geological sample type, the percent relative error was decreased from 20.0 to 0.6 for Bi and from 11.9 to 0.4 for Pb by using the proposed modifier systems. The accuracy of the determination of analytes in the synthetic sea water also increased.

Determination of lead, copper, zinc, magnesium, calcium and iron in fresh eggs by atomic absorption spectrometry

Abstract In this study, lead, copper and zinc, calcium, magnesium and iron in fresh egg samples have been determined by electrothermal and flame atomic absorption spectrometry (ETAAS–FAAS) with Zeeman-effect background correction. Y+Pd+citric acid (CA) has been found a powerful modifier mixture for the determination of Pb, Cu and Zn. Maximum pyrolysis and optimum atomization temperatures of analyte elements were determined in the presence or absence of modifiers. Atomization and background profiles of the analyte elements studied in the presence of Y+Pd+CA have been compared with other modifiers such as Mg+Pd and Mg+PO43−. The detection limits obtained were 1.88, 0.71, 0.03 ng/ml for Pb, Cu and Zn in ETAAS, 14.0, 32.3, 68.6 and 18.9 ng/ml for Mg, Ca, Fe and Zn in FAAS, respectively. The reliability of the measurements was confirmed by analysing a certified reference material, NIST, whole egg powder 8415. The percent recovery ranges of analytes were from 96.7 to 101%.

Determination of cadmium and lead in biological samples by Zeeman ETAAS using various chemical modifiers

The electrothermal atomic absorption spectrometric determination of cadmium and lead in biological certified reference materials (CRMs) has been carried out by using NH(4)H(2)PO(4), Ni, Pd, Ni+NH(4)H(2)PO(4), Pd+NH(4)H(2)PO(4) and Ni+Pd+NH(4)H(2)PO(4) as chemical modifiers. A comprehensive comparison was made among the modifiers in 1% Triton X-100 plus 0.2% nitric acid as diluent and without modifier. Zeeman background correction and graphite tubes inserted with platforms were used. Comparison was made in terms of pyrolysis and atomization temperatures, atomization and background absorption profiles. Ni+Pd+NH(4)H(2)PO(4) modifier mixture was found to be preferable for the determination of Cd and Pb. Pyrolysis temperatures of analytes were increased up to 900 degrees C for Cd and 1250 degrees C for Pb by using Ni+Pd+NH(4)H(2)PO(4) in 1% Triton X-100 plus 0.2% nitric acid diluent solution. Biological CRMs were analyzed to verify the accuracy and precision of this method. Depending on the biological sample type, the percent recoveries were increased from 62 to 102% for Cd and from 58 to 106% for Pb by using the proposed modifier mixture. The detection limits of Cd and Pb were found to be 0.04, 0.92 mug l(-1), respectively.

Determination of cadmium, copper and lead in soils, sediments and sea water samples by ETAAS using a Sc + Pd + NH4NO3 chemical modifier

Cadmium, copper and lead in soils, sediments and spiked sea water samples have been determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman effect background corrector using NH(4)NO(3), Sc, Pd, Sc + NH(4)NO(3), Pd + NH(4)NO(3), Sc + Pd and Sc + Pd + NH(4)NO(3) as chemical modifiers. A comprehensive comparison was made among the modifiers and without modifier in terms of pyrolysis and atomization temperatures, atomization and background absorption profiles, characteristic masses, detection limits and accuracy of the determinations. Sc + Pd + NH(4)NO(3) modifier mixture was found to be preferable for the determination of analytes in soil and sediment certified and standard reference materials, and sea water samples because it increased the pyrolysis temperature up to 900 degrees C for Cd, 1350 degrees C for Cu and 1300 degrees C for Pb. Optimum masses of mixed modifier components found are 20mug Sc + 4mug Pd + 8mug NH(4)NO(3). Characteristic masses of Cd, Cu and Pb obtained are 0.6, 5.3 and 15.8pg, respectively. The detection limits of Cd, Cu and Pb were found to be 0.08, 0.57 and 0.83mugl(-1), respectively. Depending on the solid sample type, the percent recoveries were increased up to 103% for Cd, Cu and Pb by using the proposed modifier mixture. The accuracy of the determination of analytes in the sea water samples was also increased.

Determination of bismuth and lead in geological samples by electrothermal AAS Part 1. Comparative study of tungsten containing chemical modifiers

Abstract A comparative study on the efficiency of some tungsten containing chemical modifiers such as W, W+Pd, W+Rh, W+Pt and W+Ru for thermal stabilization of Bi, In, Pb and Sb has been performed systematically by a Zeeman electrothermal atomization atomic absorption spectrometer (ETAAS). The addition of tartaric acid (TA) as a reducing agent additionally to the mixed modifiers was studied. A mixture of W+Pd+TA was found to be a powerful mixed modifier for the determination of Bi, In, Pb and Sb. Pretreatment temperatures could be increased up to 1250–1500° C using this mixed modifier. The use of the mixed modifier results in an enhanced accuracy and precision of the method and recovery rates above 97% for all samples. The W+Pd+TA mixed modifier was applied to the determination of Bi and Pb in dissolved geological reference samples.

Direct determination of bismuth, indium and lead in sea water by Zeeman ETAAS using molybdenum containing chemical modifiers

Direct determination of Bi, In and Pb in sea water samples has been carried out by ETAAS with Zeeman background correction using molybdenum containing chemical modifiers and tartaric acid as a reducing agent. Maximum pyrolysis temperatures and the effect of mass ratios of the mixed modifier components on analytes have been investigated. Mo+Pd+TA or Mo+Pt+TA mixture was found to be powerful for the determination of 50 mug l(-1) of Bi, In and Pb spiked into synthetic and real sea waters. The accuracy and precision of the determination were thereby enhanced. The recoveries of analytes spiked were 94-103% with Mo+Pd+TA or Mo+Pt+TA and they are only 49-61% without modifier.

Determination of bismuth, indium and lead in spiked sea water by electrothermal atomic absorption spectrometry using tungsten containing chemical modifiers

Abstract The determination of bismuth, indium and lead in spiked synthetic and natural sea water by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction was investigated using tungsten containing chemical modifiers and tartaric acid (TA) as a reducing agent. Maximum pyrolysis and optimum atomization temperatures for the analyte elements were determined in the presence and absence of various modifiers. The lowest detection limits of 8.5, 4, and 1.3 μg l −1 and characteristic mass values of 0.07, 0.04 and 0.02 ng for Bi, In and Pb, respectively, were obtained using the W+Pd+TA mixed modifier, which was found to be most powerful for the determination of Bi, In and Pb spiked into synthetic and natural sea water. The relative error was decreased from 51 to 0.2% for Bi, from 42 to 2% for In and from 51 to 1.2% for Pb by using the proposed W+Pd+TA modifier mixture.

Determination of lead in cookies by electrothermal atomic absorption spectrometry with various chemical modifiers.

Abstract The determination of lead in some Turkish cookies has been studied in the presence of some chemical modifiers. In order to decrease the interferences of sample matrix and to stabilize the atomic absorption signal of lead, W, Pd, W+Pd and W+Pd+tartaric acid (TA) have been tested as matrix modifier. Modifiers have been compared in terms of pyrolysis temperature, atomization and background profiles, precision and accuracy. The W+Pd+TA modifier mixture was found to be preferable for the determination of lead in cookies. The recovery and limit of detection of lead were about 99% and 1.2 μg/l, respectively.

Determination of lead and copper in chewing gum samples by electrothermal-flame atomic absorption spectrometry using various chemical modifiers and arsenic by hydride generation

Abstract Lead and copper in chewing gum samples were determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman background correction using various chemical modifiers and by flame atomic absorption spectrometry (FAAS) using 2% m/v ammonium pyrrolidine dithiocarbamate (APDC) complexing reagent in methyl isobuthyl keton (MIBK). Arsenic in samples was determined by hydride generation atomic absorption spectrometry (HGAAS). In order to decrease the interferences in sample matrix by ETAAS, Pd, Pt, W, Mo, Mg, PO 4 3− , their mixtures and W+Pd+tartaric acid (TA) have been tested as matrix modifiers in sample solutions. Modifiers have been compared in terms of pyrolysis temperature, atomization and background profiles of analytes. W+Pd+TA modifier mixture found as preferable was used for the determination of analytes by ETAAS. The reliability of the procedures was verified by analyzing several certified reference materials (CRMs). Detection limits of Pb and Cu determined by ETAAS and As determined by HGAAS were 1.2, 0.8 and 3.0 μg l −1 for Pb, Cu and As, respectively.