Simultaneous identification, confirmation and quantitation of illegal adulterated antidiabetics in herbal medicines and dietary supplements using high-resolution benchtop quadrupole-Orbitrap mass spectrometry.

This paper presents an application of ultrahigh-performance liquid chromatography and quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HR MS) for the screening, confirmation and quantification of 11 antidiabetics in herbal medicines and dietary supplements. The mass spectrometer was operated in Full MS/dd-MS(2) (data-dependent MS(2)) mode. The full MS scan acquired data for identification and quantification, and dd-MS(2) scan obtained product ion spectra for confirmation. UHPLC-Q-Orbitrap MS quantification was achieved using matrix-matched standard calibration curves with phenacetin as internal standard. The method validation that included selectivity, sensitivity, calibration curve, accuracy and precision, recovery, matrix effect and stability was evaluated. The response showed good linear relationship with the concentrations of analytes over wide ranges (e.g., 0.0004-1 μg/g for metformin) with all the coefficients of correlation (r(2)) >0.9991. The detection limits (LODs) were in the range of 0.05-0.5 ng/g for different analytes. The recoveries yielded results higher than 74.3% for all compounds. The accuracy was in the range of -6.75 to 3.85%, while the intra- and inter-day precision ranged from 0.048 to 11.5%. Among 63 batches of herbal medicines and 34 batches of dietary supplements samples, 7 batches of dietary supplements were positive, while all the herbal medicines were negative. Overall, the novel UHPLC-Q-Orbitrap has demonstrated great performance for identification, confirmation and quantification of antidiabetics in herbal medicines and dietary supplements, ensuring food safety and public health.