Inductively coupled plasma mass spectrometric determination of molybdenum in urine

A method was developed for the determination of molybdenum (Mo) in human urine by direct dilution of the sample in doubly distilled water with 1% HNO 3 (v/v) and inductively coupled mass spectrometry (ICP‐MS). In and Y were used as internal standards. Since 98 Mo provides a higher sensitivity, it was chosen as the reference isotope. The influence of different factors, such as sample dilution, HNO 3 concentration and the stability of the analyte were evaluated. The detection limit (LOD) was assessed at 0.2 µg/L Mo, while the lower limit of quantification (LOQ) was 0.6 µg/L. Recoveries ranged between 97.2 and 100.7% from solutions containing from 10 to 50 µg/L Mo. Linear calibration curves were generated from 2.1 and 52.1 µg/L with coefficients of variation (CV ) ranging from 1.62 to 3.56%. In order to establish reference values (RV) for molybdenum, the procedure presented here was used to determine Mo in the urine of a population group living in Tuscany, Italy. Copyright © 2002 John Wiley & Sons, Ltd.