Qualitative screening for adulterants in weight-loss supplements by ion mobility spectrometry

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 71; pp. 18 - 26
• Main Authors: Dunn, Jamie D., Gryniewicz-Ruzicka, Connie M., Mans, Daniel J., Mecker-Pogue, Laura C., Kauffman, John F., Westenberger, Benjamin J., Buhse, Lucinda F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-12-2012; Elsevier
• Subjects: 2-Propanol - chemistry; adulterated products; Analysis; Analytical, structural and metabolic biochemistry; Anti-Obesity Agents - chemistry; aqueous solutions; Biological and medical sciences; detection limit; dietary supplements; Dietary Supplements - analysis; fenfluramine; Fundamental and applied biological sciences. Psychology; furosemide; General pharmacology; Hand-held; Herbal dietary supplements; Hydrogen-Ion Concentration; ingredients; Ion mobility spectrometry; Ions - chemistry; isopropyl alcohol; Medical Laboratory Science - instrumentation; Medical Laboratory Science - methods; Medical sciences; methanol; Methanol - chemistry; Pharmacology. Drug treatments; phenytoin; Portable; screening; Solutions - chemistry; solvents; Solvents - chemistry; spectrometers; spectroscopy; Spectrum Analysis - instrumentation; Spectrum Analysis - methods; toxicity; Water - chemistry; weight loss; Weight Loss - drug effects; Weight-loss drugs; HPI; LOD; FDA; Ion mobility spectrometry; PTFE; Herbal dietary supplements; CL; ESI-MS; IMS; du; Portable; DPA; FWHM; Weight-loss drugs; API; UPLC–MS; Hand-held; ORA; Drug; Weight loss; Hand; lon mobility spectrometry; Screening; Plant origin; Portable equipment; Supplementation; Adulteration; Food supplement
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2012.07.020

Ion mobility spectrometry (IMS) served as a rapid, qualitative screening tool for the analysis of adulterated weight-loss products. We have previously shown that sibutramine extracted into methanol from dietary supplements can be detected at low levels (2ng) using a portable IMS spectrometer, and have adapted a similar method for the analysis of additional weight-loss product adulterants. An FDA collaborative study helped to define the limits for fluoxetine with a limit of detection of 2ng. We also evaluated more readily available, less toxic extraction solvents and found isopropanol and water were comparable to methanol. Isopropanol was favored over water for two reasons: (1) water increases the analysis time and (2) aqueous solutions were more susceptible to pH change, which affected the detection of sibutramine. In addition to sibutamine and fluoxetine, we surveyed 11 weight-loss adulterants; bumetanide, fenfluramine, furosemide, orlistat, phenolphthalein, phentermine, phenytoin, rimonabant, sertraline and two sibutramine analogs, desmethylsibutramine and didesmethylsibutramine, using portable and benchtop ion mobility spectrometers. Out of these 13 active pharmaceutical ingredients (APIs), portable and benchtop ion mobility spectrometers were capable of screening products for 10 of these APIs. The developed procedure was applied to two weight-loss dietary supplements using both portable and benchtop instruments. One product contained didesmethylsibutramine while the other contained didesmethylsibutramine and phenolphthalein.