Faculty of Geotechnical Engineering, University of Zagreb, 42000 Varaždin, Croatia.
Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia.
Molecules. 2021 Mar 4;26(5):1366. doi: 10.3390/molecules26051366.
A novel, simple, low-cost, and user-friendly potentiometric surfactant sensor based on the new 1,3-dihexadecyl-1-benzo[]imidazol-3-ium-tetraphenylborate (DHBI-TPB) ion-pair for the detection of cationic surfactants in personal care products and disinfectants is presented here. The new cationic surfactant DHBI-Br was successfully synthesized and characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectrometry, liquid chromatography-mass spectrometry (LC-MS) and elemental analysis and was further employed for DHBI-TPB ion-pair preparation. The sensor gave excellent response characteristics for CTAB, CPC and Hyamine with a Nernstian slope (57.1 to 59.1 mV/decade) whereas the lowest limit of detection (LOD) value was measured for CTAB (0.3 × 10 M). The sensor exhibited a fast dynamic response to dodecyl sulfate (DDS) and TPB. High sensor performances stayed intact regardless of the employment of inorganic and organic cations and in a broad pH range (2-11). Titration of cationic and etoxylated (EO)-nonionic surfactant (NSs) (in Ba) mixtures with TPB revealed the first inflexion point for a cationic surfactant and the second for an EO-nonionic surfactant. The increased concentration of EO-nonionic surfactants and the number of EO groups had a negative influence on titration curves and signal change. The sensor was successfully applied for the quantification of technical-grade cationic surfactants and in 12 personal care products and disinfectants. The results showed good agreement with the measurements obtained by a commercial surfactant sensor and by a two-phase titration. A good recovery for the standard addition method (98-102%) was observed.
本文提出了一种基于新的 1,3-二十六烷基-1-苯并[]咪唑-3-𬭩-四苯硼酸盐（DHBI-TPB）离子对的新型、简单、低成本且用户友好的电位型表面活性剂传感器，用于检测个人护理产品和消毒剂中的阳离子表面活性剂。新的阳离子表面活性剂 DHBI-Br 通过核磁共振（NMR）、傅里叶变换红外（FTIR）光谱、液相色谱-质谱（LC-MS）和元素分析成功合成并进行了表征，并进一步用于 DHBI-TPB 离子对的制备。该传感器对 CTAB、CPC 和 Hyamine 具有出色的响应特性，Nernst 斜率为 57.1 至 59.1 mV/decade，而对 CTAB 的最低检测限（LOD）值为 0.3×10 M。该传感器对十二烷基硫酸盐（DDS）和 TPB 具有快速的动态响应。高传感器性能无论是否使用无机和有机阳离子以及在较宽的 pH 范围内（2-11）都保持不变。用 TPB 滴定阳离子和乙氧基化（EO）非离子表面活性剂（NS）（以 Ba 计）混合物，显示出第一个拐点为阳离子表面活性剂，第二个拐点为 EO-非离子表面活性剂。EO-非离子表面活性剂的浓度增加和 EO 基团数量的增加对滴定曲线和信号变化有负面影响。该传感器成功应用于技术级阳离子表面活性剂的定量分析以及 12 种个人护理产品和消毒剂中。结果与商用表面活性剂传感器和两相滴定法的测量结果吻合良好。标准加入法的回收率良好（98-102%）。
