Comparison of Electrospray, Atmospheric Pressure Chemical Ionization, and Atmospheric Pressure Photoionization in the Identification of Apomorphine, Dobutamine, and Entacapone Phase II Metabolites in Biological Samples

摘要: The applicability of different ionization techniques, electrospray (ESI), atmospheric pressure chemical (APCI), and a novel photoionization (APPI), were tested for the identification phase II metabolites apomorphine, dobutamine, entacapone in rat urine vitro incubation mixtures (rat hepatocytes human liver microsomes). ESI proved to be most suitable method; it enabled detection 22 conjugates, whereas APCI APPI showed only 12 14 respectively. Methyl conjugates detected with all methods. Glucuronide ionized efficiently ESI. Only some glucuronides APPI. Sulfate MS/MS experiments that site glucuronidation or sulfation could not determined, since primary cleavage was loss conjugate group (glucuronic acid SO3), no site-characteristic prod...