Using HPLC–MS and GC–MS for Improving Speed and Accuracy of Organosulfur Compound Detection

Led by the School of Pharmacy at China Medical University in Shenyang, China, a review of pretreatment and determination methods for organosulfur compounds (OSCs) in food samples since 2010 has highlighted the growing role of detection methods like high performance liquid chromatography–mass spectrometry (HPLC–MS) and gas chromatography–mass spectrometry (GC–MS) in improving the speed, efficiency, sensitivity, and accuracy of analysis (1).

White garlic pile texture. Fresh garlic on market table closeup photo. Vitamin healthy food spice image. Spicy cooking ingredient picture. Pile of white garlic heads. © Vlad - stock.adobe.com

Published in the Journal of Chromatography A, the summary funded by the Scientific Research Project of the Department of Education of Liaoning Province discusses the optimization of such pretreatments as aqueous two-phase extraction (ATPS), dispersive liquid-liquid microextraction (DLLME), dispersive solid-phase extraction (dSPE), in-tube extraction (ITEX), liquid-liquid extraction (LLE), microwave-assisted extraction (MAE), pressured liquid extraction (PLE), solid-phase extraction (SPE), solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), supercritical fluid extraction (SFE), and ultrasound assisted emulsification-microextraction (USAEME) (1).

In addition to HPLC–MS and GC–MS, the researchers also tracked the effectiveness of Fourier transform infrared (FT-IR) resonance, high performance thin layer chromatography (HP-TLC), selected ion flow tube mass spectrometry (SIFT-MS), and the sulfur chemiluminescence detector (SCD), and the applicability of each.

OSCs contain sulfur atoms mixed with a carbon atom or cyanate group. They are mostly found in garlic (Allium sativum L.), being one of that food’s foremost bioactive components and accounting for its pungent smell, but can also be detected in other vegetables including broccoli, kohlrabi (turnip cabbage), leeks, and onions. Cysteine, methionine, γ-glutamine peptide, S-alkane cysteine sulfoxide, glucosinolates, thiols, thiosulfinate and sulfur ether volatile organic compounds, and sulfur-containing amino acids are among known OSCs in food.

Because characteristics of OSCs can be easily hydrolized or are otherwise unstable, according to the study, quicker and more precise analysis by HPLC–MS, GC–MS, and related methods is needed to more accurately document OSC contents in different vegetables and gain more information about their biological usefulness.

Some physiological and pharmacological effects of long-term consumption of OSCs are lower blood pressure and cholesterol, inhibited platelet aggregation, enhanced liver protection, and antibacterial, antioxidant, anti-inflammatory, and anti-cancer functions.

In explaining the need for an update on OSC detection, the researchers said only two previous studies since 2010, one each in 2016 and 2017, examined pretreatment and determination methods, and those were more focused on literature review, or contrasting traditional and contemporary techniques. This study claims that developments in the last 10 years necessitated a forward-looking study to not only discuss advantages, disadvantages, and future prospects, but also to call attention to more environmentally friendly modern approaches.

Reference

(1) Ma, J.-H.; Zhong, Y.; Zhou, Y.; Zhang, Y.; Feng, X.-S. Organosulfur in food samples: Recent updates on sampling, pretreatment and determination technologies. J. Chromatogr. A 2023, 1689, 463769. DOI: 10.1016/j.chroma.2022.463769