Determination of lead isotope using ICP-MS and study on traceability of lead among lead-poisoning children

Objective To optimize the method for determining lead isotope ratios (LIR) using a high-precision inductively coupled plasma mass spectrometer (ICP-MS), aimed at tracing the source of lead exposure in children with lead poisoning.

Methods By optimizing data acquisition parameters and selecting relevant modes, an ICP-MS method for LIR determination was established. Four hospitalized children with lead poisoning were studied, and their blood samples, urine samples, and related environmental samples were collected. The established LIR method was applied to analyze the blood samples, urine samples, and environmental samples, and a two-dimensional source tracing model was used to trace the source of lead exposure.

Results Under the optimized conditions of the instrument, the actual measured values of ^204/206Pb, ^207/206Pb, and ^208/206Pb were close to the certified values, at (0.058 88 ± 0.000 22), (0.915 31 ± 0.000 97), and (2.167 02 ± 0.001 73), respectively; the precision of the measured values for ^204/206Pb, ^207/206Pb, and ^208/206Pb were 0.37%, 0.11%, and 0.08%, respectively. In the lead source tracing of the poisoned children, the LIR in two children was similar to that of red lead powder used by themselves, and two children were related to environmental lead.

Conclusions A more sensitive analytical method using an inductively coupled plasma mass spectrometer was established for the determination of LIR in blood, urine, and environmental samples and for analyzing the source of lead.