Confirmation of diminazene diaceturate in bovine plasma using electrospray liquid chromatography–mass spectrometry

Diminazene diaceturate is used as a trypanocide for cattle in tropical regions. This paper describes a LC–MSn method to confirm the presence of diminazene in bovine plasma. Bound diminazene in plasma samples was freed with dilute phosphoric acid, then concentrated on a bonded C18 SPE cartridge. The LC–MSn method utilized electrospray ionization coupled with an ion trap mass spectrometer. Ions observed in MS2 and MS3 product ion spectra, as well as those from the MS1 spectrum, were monitored. The method was validated with plasma samples fortified with diminazene diaceturate (4–100 ng/mL). Diminazene was confirmed in samples fortified with diminazene diaceturate at levels of 6.4 ng/mL or higher.