Determination of triclosan, triclocarban and methyl-triclosan in aqueous samples by dispersive liquid–liquid microextraction combined with rapid liquid chromatography

Abstract

a b s t r a c tIn this study, dispersive liquid-liquid microextraction (DLLME) combined with ultra-high-pressure liquid chromatography (UHPLC)-tunable ultraviolet detection (TUV), has been developed for pre-concentration and determination of triclosan (TCS), triclocarban (TCC) and methyl-triclosan (M-TCS) in aqueous samples. The key factors, including the kind and volume of extraction solvent and dispersive solvent, extraction time, salt effect and pH, which probably affect the extraction efficiencies were examined and optimized. Under the optimum conditions, linearity of the method was observed in the range of 0.0500-100 g L −1for TCS, 0.0250-50.0 g L −1 for TCC, and 0.500-100 g L −1 for M-TCS, respectively, with correlation coefficients (r 2 ) > 0.9945. The limits of detection (LODs) ranged from 45.1 to 236 ng L −1 . TCS in domestic waters was detected with the concentration of 2.08 g L −1 . The spiked recoveries of three target compounds in river water, irrigating water, reclaimed water and domestic water samples were achieved in the range of 96.4-121%, 64.3-84.9%, 77.2-115% and 75.5-106%, respectively. As a result, this method can be successfully applied for the rapid and convenient determination of TCS, TCC and M-TCS in real water samples.

Temperature-controlled ionic liquid dispersive liquid phase microextraction combined with ultra-high-pressure liquid chromatography for the rapid determination of triclosan, triclocarban and methyl-triclosan in aqueous samples

“…However, when the alkalinity ascended to pH 11, the recovery of TCS decreased. The phenomena may be explained by the structure characteristics of the compounds [21]. TCS predominates the phenolate form and could be rapidly photo-degraded in the presence of sunlight under alkaline conditions of pH>8 in water [25].…”

“…Because TCS, TCC and M-TCS have high log octanol-water partition coefficient of 4.8, 4.9 and 5.2 [17], respectively, they are easy to transfer into the phase of IL from water and acquire higher enrichment factors. Guo et al [21] have promoted a method of dispersive liquid-liquid microextraction (DLLME) to detect TCS, TCC and M-TCS. However, there exist inevitable defects in the developed method, including the consumption of volatile and toxic halogenated hydrocarbon as the extraction solvent, and the use of a third organic component as the dispersive solvent with higher LODs of target compounds (45.1 to 236 ng L…”

“…In order to obtain maximum extraction efficiency, significant experimental factors that would influence the enrichment performance were investigated and discussed in detail in the following sections, including the types and amount of ionic liquids, volume of diluting methanol, extraction time, salt effect and pH value. Extraction recovery was used to assess the optimized parameters as described by Guo et al [21] and Li et al [22]. The spiked concentrations of compounds in the water samples were 100 g L 1 for TCS and M-TCS, and 50.0 g L 1 for TCC.…”

Improved SPE-UPLC-UV-based method for the simultaneous determination of triclocarban and triclosan in wastewater

“…Several analytical methods have been proposed to detect TCS or TCC in environmental samples [8][9][10][11]. Since the concentrations of these compounds are normally low in aquatic environment, extraction/pretreatment procedures, and high-sensitivity instruments are necessary for their final determination.…”

“…Since the concentrations of these compounds are normally low in aquatic environment, extraction/pretreatment procedures, and high-sensitivity instruments are necessary for their final determination. Their general pretreatment methods reported include liquid-liquid extraction (LLE) [12], dispersive liquid-liquid microextraction (DLLME) [10,11], solid-phase extraction (SPE) [8,13], solid-phase microextraction (SPME) [14], hollow fiber assisted liquid-phase microextraction (HF-LPME) [15], and stir bar sorptive extraction (SBSE) [16]. However, TCC and TCS are not closely related in molecular structure (Fig.…”