Capillary electrophoresis with contactless conductivity detection as an affordable and versatile tool for screening illegal synthetic compounds in herbal-based products and nutrition supplements

In this study, an affordable and versatile tool for screening illegal synthetic compounds in herbal-based products and nutrition supplements is proposed and discussed. The approach is based on capillary electrophoresis (CE) instrumentation, with the evolution from purpose-made to modular setups, coupled with capacitively coupled contactless conductivity detection (C 4 D). Viewpoints on the use of purpose-made CE-C 4 D towards modular systems for food quality control in Vietnam are provided. Our CE-C 4 D approach was applied to screen a number of various synthetic compounds illegally used in different herbal-based products and nutrient supplements, including i) determination of phenylpropanolamine, fenfluramine, sibutramine, and benzylsibutramine in weight-loss products, ii) analysis of propranolol, terazosin, and furosemide in products for hypertension treatment, iii) screening of sildenafil, homosildenafil, vardenafil, vardenafil acetyl, mirodenafil, hydroxy acetildenafil in nutrients for male sexual health and iv) identification of hypoglycemic agents (metformin, phenformin, glibenclamide, gliclazide) in diabetic treatment drugs. Good agreement between results obtained with our CE-C 4 D methods and those from the established confirmation method (LC-MS/MS) was achieved, with deviation less than 10 % for all categories of investigated compounds. • An affordable tool for screening illegal synthetic compounds in nutrition supplements. • Control of weight-loss, male sexual, diabetic and hypertension treatment products. • Cross-check with the established method to prove the reliability of the CE-C 4 D approach. • Viewpoints on the evolution of CE-C 4 D for widespread use and technology transfer.