Determination of lead in bone tissues by axially viewed inductively coupled plasma multichannel-based emission spectrometry

Abstract

A new procedure for determining low levels of lead in bone tissues has been developed. After wet acid digestion in a pressurized microwave-heated system, the solution was analyzed by inductively coupled plasma multichannel-based emission spectrometry. Internal standardization using the Co 228.615 nm reference line was chosen as the optimal method to compensate for the matrix effects from the presence of calcium and nitric acid at high concentration levels. The detection limit of the procedure was 0.11 microg Pb g(-1) dry mass. Instrumental precision at the analytical concentration of approximately 10 microg l(-1) ranged from 6.1 to 9.4%. Precision of the sample preparation step was 5.4%. The concentration of lead in SRM 1486 (1.32+/-0.04 microg g(-1)) found using the new procedure was in excellent agreement with the certified level (1.335+/-0.014 microg g(-1)). Finally, the method was applied to determine the lead in various fish bone tissues, and the analytical results were found to be in good agreement with those obtained through differential pulse anodic stripping voltammetry. The method is therefore suitable for the reliable determination of lead at concentration levels of below 1 microg g(-1) in bone samples. Moreover, the multi-element capability of the technique allows us to simultaneously determine other major or trace elements in order to investigate inter-element correlation and to compute enrichment factors, making the proposed procedure particularly useful for investigating lead occurrence and pathways in fish bone tissues in order to find suitable biomarkers for the Antarctic marine environment.