Recently, the number of the cases in which weight loss products have been sold with illegal adulterants has increased, as awareness of the problems of obesity grows. In this study, we developed simultaneous analysis methods to rapidly and accurately identify ingredients illegally mixed with foods and dietary supplements. Twenty-three anti-obesity drugs in foods and dietary supplements were determined by developed and validated UPLC and LC-MS/MS methods. The UPLC method were validated for the LOD and LOQ in the ranges 0.05-3.0 and 0.2-10.0 μg/mL, respectively. The determination coefficient was over 0.999, precision was <6.2 %, and the accuracy was 80.8-103.9 %. The mean recoveries ranged from 80.3 to 109.3 % and RSD of stability was less than 2.1 %. The determination of the 23 anti-obesity drugs was accomplished by electrospray ionization LC-MS/MS using multiple reaction monitoring (MRM). The LODs and LOQs were in the ranges 0.03-7.5 and 0.09-30.0 ng/mL, respectively. The LC-MS/MS method was validated for linearity (r(2) > 0.99), precision (RSD < 10.7 %), accuracy (94.1-109.1 %), recovery (80.5-113.5 %), and the RSD of stability was <7.8 %. Using the newly developed and validated method, 193 samples were tested, and 55 were found to be adulterated.
Keywords: Adulterant; Anti-obesity drug; LC-MS/MS; UPLC; Validated.