Chromatographic Isolation of Molybdenum From Human Blood Plasma and Determination by Inductively Coupled Plasma Mass Spectrometry With Isotope Dilution

Abstract

A method was developed for the determination of Mo in human blood plasma by ion-exchange chromatography and inductively coupled plasma mass spectrometry (ICP-MS). Molybdenum was isolated from the plasma matrix by microwave digestion and anion exchange on an alumina column. Recoveries were 88±10% (±1 standard deviation, n =4) from a solution that contained 5 ppb Mo and 92 ppm phosphate, and 82±5% ( n =5) for a solution containing 0.5 ppb Mo and 92 ppm phosphate. The RSD of the count rate for ⁹⁸ Mo ⁺ at 0.5 ppb was 5–10% and the ⁹⁴ Mo/ ⁹⁸ Mo ratio had an RSD of 0.5–2.0%. The detection limit for Mo was 1 ng l ^-1 . The average Mo concentration in reference bovine serum determined by the proposed method was 10.2±0.4 ng g ^-1 , compared with the certified value of 11.5±1.1 ng g ^-1 (95% confidence interval). The Mo concentration in one pool of human blood plasma from two healthy male donors was 0.5±0.1 ng g ^-1 .