Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

摘要: A method has been developed for the direct simultaneous determination of Cd and Pb in white red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior both analytes during pyrolysis atomization stages were investigated 0.028 mol l−1 HNO3 1+1 v/v diluted mixtures Pd(NO3)2+Mg(NO3)2 NH4H2PO4+Mg(NO3)2 as chemical modifiers. With 5 μg Pd+3 Mg modifiers two-step (10 s at 400°C 10 600°C), formation carbonaceous residues inside was avoided. For 20 μl sample (wine+0.056 HNO3, 1+1, v/v) dispensed into tube, analytical curves 0.10–1.0 5.0–50 ranges established. characteristic mass approximately 0.6 pg 33 Pb, lifetime 400 firings. limits detection (LOD) based on integrated absorbance (0.03 Cd, 0.8 Pb) exceeded requirements Brazilian Food Regulations (decree #55871 from Health Department), which establish maximum permissible level 200 500 l−1. relative standard deviations (n=12) typically <8% <6% Pb. recoveries added to samples varied 88 107% 93 103%, respectively. accuracy checked table wines comparing results those obtained digested single-element ET-AAS, agreement 95% confidence level.