Development of immunosorbents coupled on-line to immobilized pepsin reactor and micro liquid chromatography–tandem mass spectrometry for analysis of butyrylcholinesterase in human plasma

摘要

Highlights?Comparison of two sorbents for the grafting of monoclonal antibodies.?On-line set-up for HuBuChE analysis including immunoextraction and digestion.?Fast, efficient, specific and sensitive method applied to plasma samples.AbstractHuman butyrylcholinesterase (HuBuChE) has been widely used as a biomarker of exposure to organophosphorus (OPs) warfare agents. Indeed, intoxication by OPs can be proven by LC–MS/MS analysis of a specific HuBuChE nonapeptide on which OPs covalently bind. Therefore, we developed a fast, selective and sensitive on-line set-up for the analysis of HuBuChE from plasma that combines immunoextraction by anti-HuBuChE antibodies, pepsin digestion on Immobilized Enzyme Reactors (IMER) and microLC–MS/MS analysis of the target nonapeptide, FGESAGAAS.Two pepsin-based IMERs were prepared and characterized in terms of grafting and digestion yields and were coupled on-line to microLC–MS/MS analysis. In addition, immunosorbent