Sensitive determination of chloroanilines in water samples by hollow fiber-based liquid-phase microextraction prior to capillary electrophoresis with amperometric detection.

A hollow fiber-based liquid-phase microextraction method has been developed for enrichment of trace chloroanilines in water samples. Target analytes including aniline, three mono-chlorinated aniline isomers (o-chloroaniline, m-chloroaniline, and p-chloroaniline) and four mono-chlorinated methylaniline isomers (2-chloro-4-methylaniline, 3-chloro-4-methylaniline, 4-chloro-2-methylaniline, and 5-chloro-2-methylaniline) were determined by CE with amperometric detection after microextraction. Several factors that affect separation, detection, and extraction efficiency were investigated. Under the optimum conditions, eight aniline compounds could be well separated from other components coexisting in water samples within 25 min, exhibiting a linear calibration over three orders of magnitude (r > 0.998); the obtained enrichment factors were between 51 and 239, and the LODs were in the range of 0.01-0.1 ng/mL. The proposed method has been applied for the analyses of real environmental water and sewage samples with relative recoveries in the range of 83-108%.