Determination of synthetic drugs used to adulterate botanical dietary supplements using QTRAP LC-MS/MS

Abstract

Adulteration of botanical dietary supplements with prohibited synthetic drugs has become a serious problem. In this paper, a method for testing synthetic drugs used to adulterate botanical dietary supplements was developed using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) coupled with a linearity ion-trap system in the multiple reaction monitoring (MRM) plus enhanced product ion (EPI) mode. Twenty-three drugs exhibiting various pharmacological effects, comprising blood pressure and lipid-lowering agents, sedative drugs, anti-diabetic drugs, weight-reducing agents and aphrodisiac compounds, were studied. For all drugs, a single transition was monitored using protonated molecules as precursor ions. EPI spectra were stored in a library and recognized by library searching. Several undeclared drugs were identified in herbal remedies, e.g., glibenclamide, sibutramine hydrochloride and sildenafil. Overall, 35 positive samples were found out of a total of 105 botanical dietary supplements tested. The method was selective, sensitive, rapid, high-throughput and reliable.

Keywords:

• botanical dietary supplements
• synthetic drugs
• adulteration
• liquid chromatography-tandem mass spectrometry (LC-MS/MS)
• QTRAP

Acknowledgement

This research was supported financially by the Science & Technology Commission of Shanghai Municipality, P. R. China (Grant No. 05dz05006). The authors thank Applied Biosystems (China) for instrumentation facilities providing, Dr Jian Le, Mr Hongjian Jiang, and Ms Ying Tan for their assistance during the study.