Evaluation of an Ion-Associate Phase Formed In Situ from the Aqueous Phase by Adding Benzethonium Chloride and Sodium Ethylbenzenesulfonate for Microextraction

Abstract

The concentration region at which the solvent is formed during in situ solvent formation microextraction is determined by varying the concentrations of the two components required to form a solvent. In particular, a solvent is formed in situ during ion-associate phase (IAP) microextraction by mixing an aqueous solution with an organic cation and an organic anion. In this study, benzethonium chloride (BenCl) and sodium ethylbenzenesulfonate (NaEBS) were employed as the organic cation and anion sources of model IAPs to thoroughly investigate the in situ solvent formation. Additionally, the formation of the IAPs and the solvent via centrifugation of the formed ion associates was examined. We demonstrated that ion associates are formed when the product of [EBS] and [Ben] is greater than the solubility product and [EBS] is greater than [Ben]. The highest extraction of polycyclic aromatic hydrocarbons (PAHs) was achieved with an amount of NaEBS 40 times greater than that of BenCl. A higher hydrophobicity in the IAP extraction of PAHs, estrogens, and pesticides facilitated extraction into the IAP.

In Situ Formed Organic Ion-Associate Liquid-Phase Microextraction without Centrifugation from Aqueous Solutions Using Thymol Blue and Estrogens

“…To calculate %E for BPA and estrogens, we used the slopes of the calibration curves in the first and second extractions [17]. Equation (3) was then employed to calculate the logarithm of the distribution coefficient (log D) based on the obtained %E and the volumes of IALP and the aqueous phase.…”

“…Liquid-phase microextraction is a pretreatment method based on the in situ formation of a new liquid phase, often requiring centrifugation or heating unless halogenated organic materials are used. Liquid-phase microextraction encompasses homogeneous liquid−liquid extraction [7], cloud point extraction [8], dispersed liquid−liquid microextraction [9][10][11], and ion-associate liquid phase (IALP) microextraction [12][13][14][15][16][17][18]. These methods are widely used for pretreatment and concentration because of their ecofriendliness, as they generate small amounts of liquid waste and offer the advantages of high speed (several minutes), high enrichment factors (several dozen times or more), and concentration to small volumes (1 µL-1 mL).…”

“…Although centrifugation is required for phase separation, alternative phase separation methods such as membrane processes have been developed [19]. The generated IALPs are diluted with organic solvents or back-extracted into acidic solutions and analyzed via atomic spectrometry [14][15][16] or high-performance liquid chromatography (HPLC) [13,17]. Some IALPs can be directly injected into HPLC systems [18].…”

“…Moreover, IALP extraction allows various extractants to be generated by changing the organic cation/anion combination and has been applied to the analysis of ammonia [12], nitrite ions, di(2-ethylhexyl) phthalate [13], heavy metals [14,16], polycyclic aromatic hydrocarbons [17], lithium [15], and bisphenol A (BPA) [18]. In our study on BPA [18], the amounts of ethylhexyloxypropylammonium cation (EHOPA + ) and dodecyl sulfate anion (DS − ) added were examined, revealing that IALPs separated relatively quickly at higher amounts without centrifugation.…”

Aqueous Two-Phase Systems Based on Cationic and Anionic Surfactants Mixture for Rapid Extraction and Colorimetric Determination of Synthetic Food Dyes

“…In this work, we studied ATPSs based on the cationic surfactant, benzethonium chloride (BztCl), which has antiseptic and anti-infective properties and is used in detergents, softeners, and cosmetics, as well as in the food industry as a disinfectant for surfaces. In addition, the benzethonium cation is known as a component of some ionic liquids, an ion-associated phase in two-phase systems, and some eutectic solvents [ 42 , 43 , 44 ]. The anionic surfactants were sodium N-lauroylsarcosinate (NaLS) and sodium dihexylsulfosuccinate (NaDHSS).…”