“…Several methods have been reported for the determination of NIC, COT and related alkaloids in various biological fluids, and those include immunoassays [18][19][20][21], gas chromatography (GC) coupled to either flame ionisation (FID) [22] or mass spectrometric (MS) detection [1,12,[23][24][25][26], high-performance liquid chromatography (LC) coupled to UV detector [27,28] or MS [7,16,[29][30][31][32][33][34][35][36]. Hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) methods have been also reported [33].…”