Using ion-pair reversed-phase HPLC ICP-MS to simultaneously determine Cr(III) and Cr(VI) in urine of chromate workers

Urinary chromium speciation analysis can provide available information of the individual exposure levels of Cr(VI) compounds. An analytical method based on ion-pair reversed-phase HPLC combined with ICP-MS to simultaneously determine Cr(III) and Cr(VI) in human urine has been developed for assessing the occupational exposure to chromate. The separation conditions of the method, including the pH value, the concentrations of ion-pair reagent and methanol in the mobile phase were studied. Specially, a high-speed polyetheretherketone (PEEK) column and a typical sample introduction method were employed to avoid the exogenous chromium contamination during the analysis. The separation of Cr(III) and Cr(VI) could be finished within 4 min with the detection limits as low as 0.03 μg L−1 at 100 μL injections for both of them, providing a convenient method for routine analysis of chromium species. The chromium species in urine of chromate workers were monitored using the developed method. The statistical analysis showed a significant relationship (n = 32, p < 0.01) between the urinary Cr(VI) and the individual airborne exposure levels, indicating that the urinary Cr(VI) could be used as a convenient and suitable monitor for high level Cr(VI) occupational exposure.