| A protein precipitation, isotope dilution, inductively coupled plasma mass spectrometry (ICP-MS) method was developed to provide rapid sample preparation procedure and accurate analysis of lead concentrations in biological samples. The method developed was used to analyze lead concentrations in blood, plasma, and red blood cells (RBC) of six lead poisoned children who were treated with oral drug dimercaptosuccinic acid (DMSA). Lead in urine and multielement Ca, Mg, Fe, Cu, and Zn in plasma and urine of above six lead poisoned children were analyzed by the ICP-MS external standard method.;The experimental results showed that DMSA therapy caused the redistribution of lead from RBC to plasma in lead poisoned children and the increased plasma lead level was related to higher urinary lead excretion. This suggested that lead elimination by DMSA chelation therapy through kidney was correlated to plasma lead concentrations. Plasma lead was chelatable with DMSA therapy. Results from RBC lead analysis showed that DMSA therapy caused a high rebound effect of bone lead to blood lead. Multiple courses of DMSA therapy can be used to mobilize and remove lead stored in bone, and eventually reduce the body lead burden of lead poisoned children. Results from multielement analysis in urine showed that DMSA therapy did not cause a significant elevation in the excretion of minerals Ca, Mg, Fe, Cu and Zn in response to multiple courses of DMSA therapy. DMSA is a therapeutically specific drug for the treatment of childhood lead poisoning. The results from multielement analysis in plasma revealed that zinc deficiency in lead poisoned children helped develop a high plasma lead level and a high ratio of plasma lead to RBC lead. Sufficient nutritional status of the essential element zinc played an important role in the efforts to reduce plasma lead levels in lead poisoned children and thus further prevent lead from entering the critical organs such as brain and central nervous system.;An isotope mixing model (206Pb/207Pb) was designed to investigate lead absorption and metabolism in two patients poisoned from lead-based paint and from gunshot bullet, respectively. |
