Highly sensitive detection of an antidiabetic drug as illegal additives in health products using solvent microextraction combined with surface-enhanced Raman spectroscopy

Abstract

A rapid and accurate method for the sensitive detection of illegal drug additives including atenolol (ATN), metformin hydrochloride (MET), and phenformin hydrochloride (PHE) in health products using solvent microextraction (SME) combined with surface-enhanced Raman spectroscopy (SERS) was developed. Various illegal drug additives in different health products were separated via microextraction and then detected in situ using a portable Raman spectrometer with Ag colloids acting as SERS-active substrates. The effects of experimental parameters on the detection sensitivity and producibility were evaluated, and the applications of illegal additives spiked into samples were systematically investigated with SME-SERS. It was demonstrated that the mixture of CH₃OH and CHCl₃ (v/v = 1 : 4) as the extractant was suitable for the rapid microextraction separation of illegal drug additives and also induced the distribution of the Ag colloids (2 M) on the CHCl₃ surface. More importantly, CH₃OH can carry the drug molecules to enter into the inter-particles of the Ag colloids in this process, and then significantly improve the detection sensitivity of illegal drug additives. Furthermore, the high-throughput and real-time detection of illegal drug additives spiked into health products with SME-SERS in multi-well 96 plates were achieved with the level of 0.1 μg mg⁻¹. The results reveal that this rapid and convenient method could be used for the effective separation and sensitive detection of illegal additives in complex specimen.