Human Plasma Copper Proteins Speciation by Size Exclusion Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometry. Solutions for Columns Calibration by Sulfur Detection

摘要

Among the hyphenated techniques used to probe andnidentify metalloproteins, size exclusion chromatographyncoupled to inductively coupled plasma mass spectrometryn(SEC-ICP-MS) has shown to have a central place. However,nthe calibration of SEC columns reveals to be tedious andnalways involves UV detection prior to ICP-MS. The presencenof sulfur in 98% of proteins allows their detection by quadrupolenICP-MS, despite the isobaric interference (16O16O) onnS, by monitoring 32S16O at mass to charge ratio (m/z) 48.nThe formation of SO occurs spontaneously in the argonnplasma but can be optimized by the introduction of oxygenngas into a reaction cell (RC) to achieve nM levels. In thisnarticle, sulfur detection was discussed upon instrumentalnconditions and S detection was then optimized by applyingnO2 as a reaction gas. SO formation was used to calibratenSEC columns without UV detection. This simple SEC-ICPMSmethodnwas used for plasma copper proteins in plasmanhealthy subjects (HS) and an untreated Wilson diseasen(WD) patient. Copper proteins identified in healthy subjectsnwere transcuprein, ceruloplasmin (Cp) and albumin. Thenmethod led to results in good agreement with other methodsnof determination. Copper bound to Cp in the WDnpatient was lowered with regard to the HS, and the exchangeablenCu was highly increased.