Analysis of trace metals in single droplet of urine by laser ablation inductively coupled plasma mass spectrometry

Abstract

Inductively coupled plasma mass spectrometry (ICP-MS) is now widely accepted as a universal and sensitive analytical technique in different research fields. In this project, we applied the technology to the analysis of complex matrix composition by using urine samples from Fabry disease patients and controls. The aims of the project were: (1) to develop a new and rapid analytical procedure for the determination of trace metal concentrations in single droplets of urine using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS); and (2) to establish preliminary results for trace metal concentrations in Fabry disease patient urine samples and controls. The processing of samples required only drying a homogeneous urine sample. Different supports (or sample substrates) were used: Teflon sheets, Whatman 903 filter paper, Urine Kid paper and glass slides. In order to establish the merits of the analytical method developed, matrix-matched synthetic laboratory standards spiked with analytes of interest were prepared at low concentrations (μg L −1 level). The precision and accuracy of the analytical method were <20% (LA-ICP-MS) for trace metals in 1 μL urine laboratory standards (at analyte concentrations of 300 ng mL −1). The limit of detection varied from 0.003 to 0.58 μg g −1 for lithium, boron, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, arsenic, rubidium, strontium, molybdenum, silver, cadmium, barium, lead, and uranium. LA-ICP-MS allowed the quantification and comparison of different trace metals in urine samples from a Fabry disease patient and from a reference control individual. This method may be applicable to forensic science, particularly when only a small amount of dried urine sample is available for investigation.