A Collaborative Study: Determination of Mycotoxins in Corn, Peanut Butter, and Wheat Flour Using Stable Isotope Dilution Assay (SIDA) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

A collaborative study was conducted to evaluate stable isotope dilution assay (SIDA) and LC-MS/MS for the simultaneous determination of aflatoxins B, B, G, and G; deoxynivalenol; fumonisins B, B, and B; ochratoxin A; HT-2 toxin; T-2 toxin; and zearalenone in foods. Samples were fortified with 12 C uniformly labeled mycotoxins (C-IS) corresponding to the native mycotoxins and extracted with acetonitrile/water (50:50 v/v), followed by centrifugation, filtration, and LC-MS/MS analysis. In addition to certified reference materials, the six participating laboratories analyzed corn, peanut butter, and wheat flour fortified with the 12 mycotoxins at concentrations ranging from 1.

Screening for multiple weight loss and related drugs in dietary supplement materials by flow injection tandem mass spectrometry and their confirmation by liquid chromatography tandem mass spectrometry.

A new method has been developed using flow injection tandem mass spectrometry to semi-quantitatively screen for weight loss drugs, including sibutramine, N-desmethylsibutramine, N-didesmethylsibutramine, and phenolphthalein in dietary supplements. Positive identification of these drugs in samples was further confirmed and quantified by liquid chromatography tandem mass spectrometry. The degradation products of sibutramine were observed and identified by LC-MS/MS which include N-desmethylsibutramine, N-didesmethylsibutramine, N-formyldesmethylsibutramine, and N-formyldidesmethylsibutramine.

Screening for multiple phosphodiesterase type 5 inhibitor drugs in dietary supplement materials by flow injection mass spectrometry and their quantification by liquid chromatography tandem mass spectrometry.

A flow injection tandem mass spectrometry method (FI-MS/MS) has been developed to detect enzyme phosphodiesterase type 5 inhibitors, including tadalafil, sildenafil, and vardenafil. Multiple reaction monitoring (MRM) was used to detect the drugs and product ion ratios were used for identification. FI-MS/MS was used for semi-quantification and liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for further confirmation and quantification.

Fast screening of lovastatin in red yeast rice products by flow injection tandem mass spectrometry.

Drug adulteration in dietary supplement materials is a world-wide problem and poses a regulatory challenge. Red yeast rice is a product used by consumers to lower blood levels of cholesterol. While most current methods to analyze red yeast rice are based on HPLC separation with a photo-diode array detector and/or a mass spectrometry detector, which takes 20-40min analysis time per sample, we developed a method to do fast screening of the active compound lovastatin by direct infusion into a mass spectrometer.