Simultaneous determination of triclosan, triclocarban, and transformation products of triclocarban in aqueous samples using solid-phase micro-extraction-HPLC-MS/MS.

The presence of triclosan and triclocarban, two endocrine-disrupting chemicals and antimicrobial agents, and transformation products of triclocarban, 1,3-di(phenyl)urea, 1,3-bis(4-chlorophenyl)urea and 1,3-bis(3,4-dichlorophenyl)urea, in tap water, treated household drinking water, bottled water, and river water samples were investigated using solid-phase micro-extraction coupled with-HPLC-MS/MS, a rapid, green, and sensitive method. Factors influencing the quantity of the analytes extracted onto the solid-phase micro-extraction fiber, such as addition of salt, sample pH, extraction time, desorption time, and sample volume, were optimized using solid-phase micro-extraction-HPLC-MS/MS. The results showed that the method gave satisfactory sensitivities and precisions for analyzing sub-part-per-trillion levels of triclosan, triclocarban, and transformation products of triclocarban in samples collected locally. The recoveries of analytes ranged from 97 to 107% for deionized water samples, and 99 to 110% for river water samples, and limits of detection were in the range of 0.32-3.44 and 0.38-4.67 ng/L for deionized water and river water samples, respectively. On average, the daily consumption of triclosan and triclocarban by an adult by consuming 2 liters of different types of drinking water were estimated to be in the range of 6.13-425 ng/day as a result of the concentrations of triclosan and triclocarban measured in this study.

Subcritical water extraction for the remediation of phthalate ester-contaminated soil.

Subcritical water has been used as an environment-friendly extraction fluid for many classes of organic compounds. It was used for the removal of phthalate esters (PEs), such as di-methyl phthalate, DMP; di-ethyl phthalate, DEP; di-iso-propyl phthalate, DIPP; di-n-butyl phthalate, DBP; benzyl butyl phthalate, BBP; di-n-pentyl phthalate, DpentP; di-n-hexyl phthalate, DHXP; di-heptyl phthalate, DheptP; di-2-ethylhexyl phthalate, DEHP; di-n-nonyl phthalate, DNP; di-n-octyl phthalate, DOP; di-n-decyl phthalate, DDP, in soil samples under the optimum condition of 250 °C and 10 MPa in our study. The soil samples cleaned with subcritical water were extracted by homemade accelerated solvent extraction system (ASE) and analyzed by HPLC-UV to check for soil remediation efficiency. Three types of soil collected at different sites in Taiwan have been tested. Although at higher PEs concentration levels, the modification of treatments may be necessary for satisfactory removal of the contaminants, soil samples of different PEs levels treated with subcritical water extraction (SCWE) were analyzed and the results indicated removal efficiency ranges of 80-90% for PEs spiked in soil samples. Soil samples contaminated with native DEHP were treated and gave comparable recovery efficiencies. Our results indicate that the applications of subcritical water as soil remediation for removal of PEs contaminant are feasible.