Potentiometric Surfactant Sensor for Anionic Surfactants Based on 1,3-dioctadecyl-1H-imidazol-3-ium tetraphenylborate

Abstract

As anionic surfactants are used as cleaning agents, they pose an environmental and health threat. A novel potentiometric sensor for anionic surfactants based on the 1,3-dioctadecyl-1H-imidazol-3-ium tetraphenylborate (DODI–TPB) ionophore is presented. The newly developed approach for DODI–TPB synthesis is faster and simpler than the currently used strategies and follows the green chemistry principles. The DODI–TPB ionophore was characterized by computational and instrumental techniques (NMR, LC–MS, FTIR, elemental analysis) and used to produce a PVC-based DODI–TPB sensor. The sensor showed linear response to dodecylbenzenesulfonate and dodecyl sulfate in concentration ranges of 6.3 × 10−7–3.2 × 10−4 M and 5.9 × 10−7–4.1 × 10−3 M, for DBS and SDS, respectively. The sensor exhibits a Nernstian slope (59.3 mV/decade and 58.3 mV/decade for DBS and SDS, respectively) and low detection limits (7.1 × 10−7 M and 6.8 × 10−7 M for DBS and SDS, respectively). The DODI–TPB sensor was successfully tested on real samples of commercial detergents and the results are in agreement with the referent methods. A computational analysis underlined the importance of long alkyl chains in DODI+ and their C–H∙∙∙π interactions with TPB– for the ionophore formation in solution, thereby providing guidelines for the future design of efficient potentiometric sensors.

Potentiometric Surfactant Sensor with a Pt-Doped Acid-Activated Multi-Walled Carbon Nanotube-Based Ionophore Nanocomposite

“…The linear response regions for both anionic surfactants were broad, up to ≈2 × 10 −6 M. This was important since it could allow the quantification of anionic surfactants over a broad concentration range, including higher but also lower anionic surfactant concentrations. Additionally, the critical micellar concentration (CMC) for both anionic surfactants was in agreement with the literature [ 30 ]. Using the proposed sensor, the CMCs for anionic surfactants could be detected.…”

Study of Cationic Surfactants Raw Materials for COVID-19 Disinfecting Formulations by Potentiometric Surfactant Sensor

“…In our recent work, we presented and characterized a new 1,3-dioctadecyl-1 H -imidazol-3-ium tetraphenylborate ion-pair prepared from the new QAC 1,3-dioctadecyl-1 H -imidazol-3-ium cation [ 37 ]. This ion-pair was used to prepare a surfactant sensor based on a DODI-TPB [ 38 ] PVC liquid membrane. The aim of the current work is to study the behavior of the developed DODI-TPB surfactant sensor in complex mixtures of technical grade cationic surfactants used in commercial disinfectants; then, to test it for the interfering effect of nonionic surfactants normally found in commercial product formulations; and finally, to use it for the quantification of cationic surfactants in commercial COVID-19 disinfectants and antiseptics for home and professional use.…”