Solid-phase microextraction coupled with high performance liquid chromatography-UV detection for the determination of di-n-propyl-phthalate, di-iso-butyl-phthalate, and di-cyclohexyl-phthalate in environmental water samples

A simple method for the determination of di-n-propyl-phthalate, di-iso-butyl-phthalate, and di-cyclohexyl-phthalate in water samples using solid-phase microextraction coupled to high performance liquid chromatography and UV detection has been developed. Several kinds of commercially available coating fibers were evaluated for their extraction performance to the target analytes and the CW/TPR coating fibre was found to be the best one. The parameters affecting the extraction efficiency, such as absorption time, extraction temperature, salting-out effect, desorption mode, were investigated and optimized. The Agilent Zorbax Eclipse XDB-C-8 column and UV detector were used for separation and detection of analytes, respectively. The mobile phase was acetonitrile-water mixture (75:25, v/v) and it was pumped at a flow rate of 0.4 mL min(-1). The developed method has been applied to determine di-n-propyl-phthalate, di-iso-butyl-phthalate, and di-cyclohexyl-phthalate in several spiked natural water samples and good recovery results (88.5-106.8%) were obtained. Detection limits of 9.5, 8.9, and 4.0 ng mL(-1) for di-n-propyl-phthalate, di-isobutyl-phthalate, and di-cyclohexyl-phthalate, respectively, were achieved under the optimized conditions.