Detection of benzalkonium chloride and polyhexamethylene guanidine hydrochloride using novel organic gel-based amperometric electrode and HILIC DAD

Abstract

This article describes the simultaneous determination of cationic surfactants benzalkonium chloride (ADBAC) and polyhexamethylene guanidine hydrochloride (PHMG) in stock solutions and commercial disinfectants using a novel voltammetric ion-selective electrode with a gel-like polymer composite membrane. The ADBAC and PHMG sensing methodology is based on a simple polyelectrolyte ion transfer reaction across the water/polyvinyl chloride-2-nitrophenyloctyl ether (PVC-NPOE) gel interface and was first investigated using cyclic voltammetry. Our novel electrode gave a current response proportional to ADBAC and PHMG ions ranging from 10 to 70 mg·L−1 and 25 to 120 mg·L−1, respectively, and the calculated detection limits were 1.24 mg·L−1 for ADBAC and 1.77 mg·L−1 for PHMG. As a comparative method for the determination and separation of ADBAC and PHMG, hydrophilic interaction chromatography (HILIC DAD) was used in combination with diode-array detection. LOD, LOQ, and RSD for recovery were determined for both methods, and a study of the analytical performance for both methods showed that the electrochemical method was more sensitive but had a larger error and a narrower range of linearity. The applicability of both methods to the routine analysis of disinfectants is discussed.