Development and Application of Novel Extraction Method to Analyze Herbal Supplements and Adulterant Determination by GCxGC/Q-TOFMS

This manuscript proposes a new extraction method for analyzing natural compounds in herbal supplements for weight loss and determining adulterants by a comprehensive two-dimensional gas chromatography system coupled to a quadrupole time-of-flight mass spectrometer (GCxGC/Q-TOFMS). In this new approach, a hydrophilic microporous cartridge (HMCart) was developed to enclose the samples, protecting the SPME (solid-phase microextraction) fibers. The cartridge is loaded with herbal supplement samples during direct immersion of SPME fiber in the aqueous phase to allow the analytes to be trapped. The new sample preparation method using chromatographic analyses enabled the detection of 650 compounds, including natural compounds, such as terpenes, aldehydes, ketones, and fatty acids. Adulterants found in other studies in the literature, such as sibutramine and ephedrine. The fluoxetine and caffeine were detected and quantified. The new method has achieved the goal of simple, effective, solvent-free, and versatile sample preparation that can be applied in future studies, including determining other compound classes in various matrix samples.