Lead concentration in feces and urine of exposed rats by x‐ray fluorescence and electrothermal atomic absorption spectrometry

Measurements made in feces and urine of Wistar rats exposed to lead acetate (n = 20) in drinking water since the fetal period were compared with those obtained from a control group (n = 20) in order to assess the age influence on Pb excretion. The measurements were made in different collections of rats aging between 1 and 11 months. To determine the Pb content of the samples, total reflection X‐ray fluorescence (TXRF) and electrothermal atomic absorption spectrometry (ETAAS) were used for the urine samples and energy dispersive X‐ray fluorescence (EDXRF) was used for the feces. The results show high concentrations of Pb being eliminated from the organism by urine and feces in contaminated rats. Values vary from (600 ± 140) µg l^?1 to (5 460 ± 115) µg l^?1 in urine and from (4 500 ± 300) µg g^?1 to (11 400 ± 3 300) µg g^?1 in dry feces. The control rats show, in general, low lead concentrations or below detection limits. The fecal/urinary ratio was studied. It was shown to be about three to four orders of magnitude and positively correlated with time. It was verified in feces and urine that excretion decreases with the animal age and that this decrease is made by different levels of excretion. The excretions of Pb in urine and in feces are positively correlated. A good agreement was found between the results obtained with TXRF and ETAAS for urine samples. This work also stresses the suitability of these techniques in the study of Pb intoxication. Copyright © 2011 John Wiley & Sons, Ltd.