Interaction study of alpha Ni3S2 with guinea pig alveolar macrophages by resonance ionization mass spectrometry

Studies on the mechanism of nickel toxicity and carcinogenesis in humans and animals have generated a great deal of interest in metal-induced diseases. However, little information exists on the cell structures implicated in nickel metabolism. The present study reports on the application of energy dispersive spectrometry (EDS) and resonance ionization spectrometry coupled with mass spectrometry (RIMS). This study deals with the uptake, incorporation and biological transformation of alpha Ni3S2 and their consequent binding to cell constituents. A RIMS technique was achieved instrumentally by coupling a commercial time-of-flight laser microprobe mass spectrometer with a dye laser. The most interesting result of this investigation was the loss of sulphur with emergence in the mass spectrum of a calcium signal in some metabolized particles. Secondly, spectral analysis of ionized cluster ions of type (NixSy)+ differs from those obtained from standards of alpha Ni3S2 showing that nickel is in an elemental form. EDS analysis of particles generated from alpha Ni3S2 in different compartments of a cell confirmed a decrease of concomitant sulphur with the appearance of an organic Ni-P complex, either with the phosphate groups of membrane phospholipids or with phospho-transferring proteins. This study showed that RIMS is a sensitive and specific analytical technique to understand the interaction of alpha Ni3S2 with cells.