Determination of Trichlorobenzenes and 2,4,6-Trichlorophenol in Wastewater of Machining by Dispersive Liquid-Liquid Microextraction - Gas Chromatography/Mass Spectrometry

Studies on the determination of trichlorobenzenes (TCBs) and 2,4,6-trichlorophenol (2,4,6-TCP) in wastewater of machining have been carried out. A gas chromatography/mass spectrometry with selected-ion monitoring acquisition method (GC/MS/SIM) was built up followed by the dispersive liquid liquid microextraction (DLLME) of the target analytes from the matrices. Comparing with some traditional methods, the present method was accurate and easier to be operated, with broader linear range, better enrichment property, replicability, and less interference. Overall recoveries were 92.5~104.3 % with RSD values at 2.3~8.7%. The detective limit was 2.0, 6.0, 3.0 and 5.0 μg/L for 1,3,5-, 1,2,4-, 1,2,3-TCB and 2,4,6-TCP, respectively. Parameters and some important factors, which may affect the recoveries and replicabilities for the determination of targent analytes, have been investigated. The present method has been applied for the determination of the TCBs and 2,4,6-TCP residues of 10 real samples. The results showed that 4 of them were found to contain TCBs and/or 2,4,6-TCP with concentration at 0.12~1.26 mg/L.