Determination of zinc and lead in human hair by atomic absorption spectrometry after digestion with tetramethylammonium hydroxide and conventional methods

Dogan, Selda

Various digestion methods were compared for determination of zinc and lead in human hair by atomic absorption spectroscopy. For the digestion of hair samples, alkaline digestion in tetramethylammonium hydroxide was used in addition to conventional acidic digestion methods like dry ashing, wet ashing and microwave digestion in acid. The accuracy of the methods was tested by certified standard reference material, CRM BCR-397 human hair. According to the statistical evaluation of the results, there are no significant differences between the four digestion methods. Relative errors of the certified value of CRM BCR-397 were less than 10% except for the tetramethyl-ammonium hydroxide digestion method.

Comparison of hydride generation atomic absorption and electrothermal atomic absorption techniques for determination of lead in blood

In this study, hydride generation atomic absorption and Zeeman background corrected electrothermal atomic absorption techniques was compared for determination of lead in blood. Blood samples were digested by microwave acid digestion and then Pb(IV) formation was realized by using (NH4)(2)Cr2O7 in 0.72 mol/l HNO3. To increase the stability of Pb(IV) different chelating agents were added. Malic acid was a more suitable chelating agent than lactic, tartaric and salicylic acids. After PbH4 was formed, NaBH4 was swept with argon into the heated quartz tube for atomization. (NH4)(2)Cr2O7 + HNO3 + malic acid medium was chosen as the most suitable medium. After these conditions were fulfilled, Pb levels of the samples were measured first by hydride generation atomic absorption and then by Zeeman b...