Laser ablation inductively coupled plasma-mass spectrometry in combination with gel electrophoresis: a new strategy for speciation of metal binding serum proteins

A new hyphenated technique-crossed immunoelectrophoresis in combination with laser ablation inductively coupled plasma (ICP)-mass spectrometry-for the identification and quantitation of metal binding proteins in blood serum is described. Human serum enriched with Co was subjected to electrophoresis and the agarose gels corresponding to the first and second dimensions were interrogated and analysed using a Nd Yag laser (1064 nm) interfaced to ICP-mass spectrometry. Comparison of the distribution map for Co with the protein distribution map obtained via Coommassie Brilliant Blue staining allowed identification of main Co binding serum proteins. Signals for Co (single ion monitoring, mle 59) were transient in nature and for gels enriched with increasing concentrations of Co, peak area response was linear with concentration. Precision for replicate analyses was 6% R.S.D. and the limit of detection was -0.29 ng. (C) 1998 Elsevier Science B.V.