Flow field-flow fractionation-inductively coupled plasma mass spectrometryand metal speciation in proteins: A feasibility study

The feasibility of trace metal speciation in proteins directly using flow f ield-flow fractionation-inductively coupled plasma mass spectrometry (FlFFF -ICP-MS) was investigated. The effect on the separation of the FlFFF system cross flow rate was demonstrated for a carbonic anhydrase and alcohol dehy drogenase mixture. Preliminary studies with FlFFF-ICP-MS were applied to se veral protein standards including metallothionein, carbonic anhydrase, ceru loplasmin, alcohol dehydrogenase, and thyroglobulin. Cadmium was detected i n metallothionein; copper and zinc in carbonic anhydrase, alcohol dehydroge nase, and ceruloplasmin, and iodide in thyroglobulin.