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 34S+ (the ratio M+/34S+) 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 μg g−1 for As and ranged from 0.3 to 7.8 μg g−1for the other analytes. Distinct elemental exposition time profiles were observed in hair samples from five volunteers.

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► LA-ICP-MS techniques for the time-resolved assessment of exposition to elements were developed.
► Matrix matched multielement hair standards and hair phantoms with segmentally differential load of As were prepared.
► Characteristic peaks with steep increase and exponential decrease corresponding to intermittent high dose Mg treatment could be detected suggesting an elimination half live of Mg of about 10 days.