To date, researching the spatial distribution of metals in biological samples or in tissue sections is most commonly performed using three sensitive mass spectrometric techniques: secondary ion mass spectrometry (SIMS) 11, particle induced x-ray emission (PIXE) 12 and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) 13. However, this analytical approach may not provide sufficient information because it ignores the spatial distribution of metals in the analysed hair strands. Thus, hair samples provide a historical record of elements assimilated from the environment 9.Įlements at trace concentration levels have been quite often determined in bulk hair samples after acid digestion using inductively coupled plasma mass spectrometry (ICP-MS) 10. Moreover, human hair grows at a rate of approximately 1 cm per month, and the level of the different elements found in hair is reflective of their levels in the body medium from which the hair was formed. Another advantage of hair analysis is the fact that the obtained results are not the result of any homeostatic mechanisms, unlike assays carried out on blood samples 8. The analysis of hair has certain advantages, including the simplicity of the matrix and the ease of sampling, transfer, and storage 7. Hair analysis for essential and toxic metals is of increasing importance in studies related to medicine 1, 2, forensics 3, archaeology 4, 5and nutrition 6. The actual and estimated times over which the drug entered the body were compared and discussed.
The spatial distribution of As along the hair was observed in a hair sample from a leukaemia patient treated with arsenic trioxide (As 2O 3). Second, an actual hair was measured using the developed method. The linear correlation coefficients (R 2) of the calibration curves for the analytes As and Pb were typically between 0.9970 and 0.9998, respectively.
The use of hair strand standards enables 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 the acidic digests. A calibration strategy in LA-ICP-MS was developed using prepared matrix-matched laboratory hair standards doped with analytes of interest at a defined concentration.
First, a method was developed and validated for the elemental analysis of hair by LA-ICP-MS. These results could subsequently be used to infer when the element entered the body.
The purpose of this study was to develop matrix-matched hair standards and a LA-ICP-MS technique for determination of the As and Pb in a single human hair using single spot scan mode.
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