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We report on a method for the determination of the biogenic amines (BAs) spermine, spermidine, histamine, cadaverine, β-phenylethylamine, tyramine and tryptamine. It is based on capillary zone electrophoresis in the presence of 18-crown-6 (180 mM), and is making use of amperometric detection. Under optimized conditions, seven BAs could be well separated within 29 min at a separation voltage of 14 kV in a buffer solution of pH 3.6. The limits of detection for seven BAs are around 10 ng.mL −1 for standard mixtures. The method does not require preconcentration and derivatization steps, and thus provides an attractive alternative to quantitative multi-analysis of BAs in water samples.

A highly selective and sensitive method was developed for the simultaneous determination of 12 sulfonamides in beef and milk by immunoaffinity chromatography purification coupled to ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The MS/MS conditions, UPLC mobile phase, injection solution, sample purification process, and matrix effect were studied to optimize the operating conditions. The limits of detection (LODs) of the instrument for the studied sulfonamides ranged from 0.4 to 2.0 μg L(-1), being 1.6-8.0 μg kg(-1) for beef and 1.8-6.4 μg kg(-1) for milk. The standard solution was diluted with blank beef or milk matrix for the construction of calibration curves, which had a linear range from 10 to 200 μg kg(-1) and regression coefficients higher than 0.990 (n=10) for all the studied sulfonamides. Samples spiked at 10, 20, and 100 μg kg(-1) showed recoveries above 70% and relative standard deviations below 10%.

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%.

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