DETERMINATION OF PHYSIOLOGICAL PALLADIUM AND PLATINUM LEVELS IN URINEUSING DOUBLE FOCUSING MAGNETIC-SECTOR FIELD ICP-MS

A new extremely sensitive method for the determination of physiologica l (normal) Pd and Pt levels in human urine is presented, applying UV p hotolysis followed by sequential determination with double focusing ma gnetic sector field ICP-MS. Due to the low blank values, which are a c onsequence of the minimal reagent addition required, UV photolysis tur ned out to be advantageous for the decomposition of the organic matrix . Sector field ICP-MS operating in the low resolution (LR) mode permit s detection limits for Pt and Pd which are distinctly lower than in th e high resolution (HR) mode or with quadrupole instruments when using a comparable sample introduction system. The practical detection limit s in urine were 0.17 ng/L Pd and 0.24 ng/L Pt using standard nickel co nes. Taking into account a dilution factor of 4.2, the detection limit s related to the final solution were 0.04 ng/L Pd and 0.06 ng/L Pt. Th e use of a high-performance nickel skimmer cone did not result in any improvement of the detection limits because the signal of the analytes and the background were enhanced to a similar extent. Urinary Pd leve ls in 21 unexposed persons ranged from 32.7 to 219.7 ng/L (arithmetic mean(AM): 140.3 ng/L), the Pt levels were between 0.48 and 7.7 ng/L (A M: 1.8 ng/L). The relevance and severity of mass spectral interference s in the Pd and Pt determination at these concentration levels have be en investigated.