Health & Environmental Research Online (HERO)


Print Feedback Export to File
356679 
Journal Article 
Direct determination of lead in human urine and serum samples by electrothermal atomic absorption spectrometry and permanent modifiers 
Andrada, D; Pinto, FG; Magalhães, CG; Nunes, BR; Franco, MB; Silva JBBd 
2006 
Yes 
Journal of the Brazilian Chemical Society
ISSN: 0103-5053
EISSN: 1678-4790 
17 
2 
328-332 
English 
WOS:000236732400016 
The object of the present study was the development of alternative methods for the direct determination of lead in undigested samples of human urine and serum by electrothermal atomic absorption spectrometry (ET AAS). Thus, some substances have been investigated to act as chemical modifiers. Volumes of 20 µl of diluted samples, 1+1, v/v for urine and 1+4, v/v for serum, with HNO3 1% v/v and 0.02% v/v of cetil trimethyl ammonium chloride (CTAC) were prepared directly in the autosampler cups and placed into the graphite furnace. For modifiers in solutions 10 µl were used. Pyrolysis and atomization temperature curves were used in all optimizations in the matrixes diluted as exposed. For urine with permanent iridium (500 µg), the best pyrolysis and atomization temperatures were 900 and 1600°C, respectively, with a characteristic mass of 12 pg (recommended of 10 pg), with symmetrical absorption pulses and corrected background. Spiked urine samples presented recoveries between 86 and 112% for Ir permanent. The analysis results of certified urine samples are in agreement with certified values (95% of confidence) for two levels of the metal. For serum, good results were obtained with the mixture of Zr+Rh or Ir+Rh as permanent modifiers, with characteristic masses of 9.8 and 8.1 pg, respectively. Recoveries from spiked serum samples varied between 98.6 and 100.1% (Ir+Rh) and between 93.9 and 105.2% (Zr+Rh). In both recovery studies, the relative standard deviation (n=3) was lower than 7%. Calibration for both samples were made with aqueous calibration curves and presented r2 higher than 0.99. The limits of detection were 0.7 µg/litre for serum samples, with Zr+Rh permanent, and 1.0 µg/litre for urine with iridium permanent. 
analytical methods; blood serum; lead; spectrometry; urine; man; Homo; Hominidae; Primates; mammals; vertebrates; Chordata; animals; eukaryotes; analytical techniques; Human Toxicology and Poisoning (VV810) (New March 2000); Techniques and Methodology (ZZ900)