Identification of sulfonylureas in serum by electrospray mass spectrometry

Identification of sulfonylureas in serum is important in the diagnosis of h ypoglycemic crisis of unknown origin, Methods based on HPLC with UV or fluo rescence detection may give false positive results. Mass spectrometry may s uccessfully avoid this problem. The described method allows the simultaneou s identification and quantification of tolbutamide, chlorpropamide, glibenc lamide, and glipizide in human serum using one of the tested sulfonylureas as the internal standard. Serum purification is carried out by solid-phase extraction with ENVI-C18 cartridges and samples are analyzed by liquid chro matography-electrospray mass spectrometry. For all drugs, the limit of dete ction and the limit of quantification are about 2 and 10 ng/ml, respectivel y. (C) 2000 Academic Press.