Validation du dosage du chrome par ICP-MS avec cellule de collision dans les matrices biologiques et concentrations usuelles

Abstract

Objective: Metal determination in biological fluids is of major concern in analytical toxicology. It not only involves human pathology, but especially, clinical, forensic or environmental toxicology. We propose a validated method for blood and urine chromium, element analysis which is particularly difficult. Method: As inductively coupled plasma mass spectrometry (ICP-MS) is the technique of choice for metals, it was used for chromium quantification. Unfortunately, due to an analytical interference at the atomic mass of 52, the chromium most abundant isotope, a collision reaction cell (CRC) was used to remove this interference produced with the carbon from the biological fluids (mass 12) and the carrier gas, argon (mass 40). Chromium determination was performed after acidic dilution with rhodium as an internal standard. Analysis was achieved according to the standard addition method for blood and urine and with aqueous calibration method for plasma. Blood and urine were collected from 30 healthy volunteers, free of trace element treatment and without orthopedic prosthesis. Results: In biological fluids, linearity, repeatability, reproducibility and accuracy were good. The limit of detection and quantification were approximately 0.1 and 0.3 μg/L respectively. For 33 volunteers, normal concentrations were below 0.7 μg/L in plasma and below 1.0 μg/L in blood and urine. This method was successfully applied to prosthesis carriers and to a rare case of potassium dichromate poisoning. Conclusion: ICP-MS-CRC applied to blood, plasma and urine is the technique of choice for chromium analysis. © 2011 Société Française de Toxicologie Analytique.