Biomonitoring for arsenic, toxic and essential metals in single hair strands by laser ablation inductively coupled plasma mass spectrometry

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been developed as reliable analytical technique for the quantitation of metal distributions at micrometre resolution. In this work a novel microanalytical strategy for biomonitoring of arsenic, toxic and essential metals in single hair strands is proposed. Two different calibration strategies in LA-ICP-MS were developed using either certified hair standard reference material (IAEA 086) or prepared matrix-matched laboratory hair standards doped with analytes of interest at defined concentration. Powdered hair standards and human hair strands mounted on a sticky tape in the LA chamber were analyzed under the same experimental conditions by an optimized LA-ICP-MS technique. The use of hair powder standard allows calibration curves to be obtained by plotting the analyte ion (M(+)) intensity normalized to (34)S(+) (the ratio M(+)/(34)S(+)) as a function of the concentration determined by ICP-MS of acidic digests. The linear correlation coefficients (R) of calibration curves for analytes As, Ba, Cd, Ce, Co, Cr, Cu, Fe, Ga, Hg, Mg, Mo, Ni, Pb, Rb, Sr, Ti and U were typically between 0.985 and 0.999. The limit of detection (LOD) was 0.6 mu g g(-1) for As and ranged from 0.3 to 7.8 mu g g(-1) for the other analytes. Distinct elemental exposition time profiles were observed in hair samples from five volunteers. (C) 2011 Elsevier B.V. All rights reserved.