Screening and simultaneous quantitative measurement of six sulfonylureas in serum by liquid chromatography mass spectrometry with atmospheric-pressure chemical-ionization (APCI LC/MS)

A method is described for the separation, identification and quantification of six sulfonylureas in serum by liquid chromatography/mass spectrometry with atmospheric-pressure chemical-ionization (APCI LC/MS). The sample pretreatment is based on single-step liquid-liquid extraction, using the 4-methylcyclohexyl analogue of glibenclamide as internal standard. Carbutamide and tolbutamide have been chosen as representative sulfonylureas of the first generation and glipizide, glibornuride, glibenclamide and gliquidone as those of the second generation, widely used in the treatment of diabetes mellitus. This method allows a screening of these sulfonylureas in serum and subsequently the quantification of the serum level in one run of measurement. Accuracy, precision, specificity and sensitivity for each sulfonylurea are presented and discussed.