Analysis of Triclocarban in Aquatic Samples by Liquid Chromatography Electrospray Ionization Mass Spectrometry

Abstract

Triclocarban, N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, is a polychlorinated phenyl urea pesticide, marketed under the trademark TCC and used primarily as an antibacterial additive in personal care products. Despite its extensive use over several decades, environmental occurrence data on TCC are scarce. This is due in part to a lack of analytical techniques offering the desired sensitivity, selectivity, affordability, and ease of use. This need is addressed here by introducing a liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) method allowing for the determination of TCC concentrations in aquatic environments at the ng/L level. TCC was concentrated from aqueous samples by solid-phase extraction, separated from interferences on a C18 column by either isocratic or gradient elution, and detected and identified in negative ESI mode by selectively monitoring the (M - H)- base peak (m/z 313) and its 37Cl-containing isotopes (m/z 315, 317) that served as reference ions. Particulates contained in aquatic samples were extracted and analyzed separately. Accurate quantification was achieved using stable isotopes of TCC and triclosan as internal standards. Addition of 10 mM acetic acid to the mobile phase yielded acetic acid adducts ([M - H + 60]-) that were successfully exploited to boost method sensitivity and selectivity, especially when analyzing challenging environmental matrixes. Method detection limits were matrix dependent, ranging from 3 to 50 ng/L. In 36 grab samples obtained from the Greater Baltimore area, TCC was detected in river water and wastewater at concentrations of up to 5600 and 6750 ng/L, respectively. Raw and finished drinking water did not contain detectable quantities of the pesticide (<3 ng/L). In conclusion, the new LC/ESI/MS method was applied successfully to collect environmental occurrence data on TCC in U.S. water resources. Study results suggest that the bacteriostat and pesticide is a frequent but currently underreported contaminant whose environmental fate and behavior deserve further scrutiny.

Electrochemistry-Mass Spectrometry Unveils the Formation of Reactive Triclocarban Metabolites

“…TCC can be added to rinse-off products in the United States and European Union in concentrations up to 1.5% (European Commission, Scientific Committee on Consumer Products, 2005;Ahn et al, 2008). In the United States, 48% of all antimicrobial bar soaps contain TCC; it is a high-production chemical and approximately a million pounds are used per year (Halden and Paull, 2004). Because of its widespread usage and its environmental persistence, TCC was found in surface waters in concentrations up to micrograms per liter (Halden and Paull, 2005;Sapkota et al, 2007).…”

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.…”

“…TCC is a weak base with a pK a = 12.77, whereas TCS is a phenolic compound with a pK a = 4.5 [9]. Therefore, these compounds are often analyzed in environmental matrices by using separate methods [8,12,13]. Recently, TCC and TCS have been determined simultaneously in water samples by using DLLME [10,11] or SPME [17] followed by high-performance liquid chromatography with mass spectrometry (HPLC/MS).…”

“…SPE is the most common technique used for cleanup of organic pollutants in various sample matrices. Some SPE methods have been aimed at the isolation of an individual TCC [8,13] or TCS [18,19]. In the SPE procedure, the desired adsorbent is an important factor to obtain good recovery and high enrichment factor.…”