Electronic tongue detection of adulteration in ginseng-based erectile dysfunction supplements

Liquid chromatography coupled with mass spectrometry remains the gold standard for the analysis of pharmaceuticals and dietary supplements. However, due to high costs and long analysis times, this technique is not suitable for large-scale screening. Although dietary supplements are legally classified as food products, they are often manufactured in pharmaceutical dosage forms and are not subject to mandatory quality control, which makes them particularly susceptible to adulteration. Therefore, there is an ongoing need for rapid, cost-effective, and easily accessible analytical techniques capable of screening dietary supplements available on the market. In this work, an electronic tongue system was proposed to detect adulteration with sildenafil (a phosphodiesterase type 5 inhibitor) in one of the most frequently adulterated dietary supplement categories. Five ginseng-based dietary supplements for erectile dysfunction and their counterparts artificially adulterated with sildenafil were investigated employing an array of cross-sensitive potentiometric sensors. Recorded sensor responses were subjected to multivariate data analysis, including PCA and PLS-DA. The multisensor system successfully discriminated between authentic and artificially adulterated samples. Moreover, undeclared sildenafil was detected in one of the tested products and subsequently confirmed by UHPLC-MS. These results demonstrate that the electronic tongue is a suitable screening method for detecting adulteration in ginseng-based dietary supplements.