Automatic in-tube SPME and fast liquid chromatography: A cost-effective method for the estimation of dibuthyl and di-2-ethylhexyl phthalates in environmental water samples

摘要

A 80-cm length commercially available capillary coated with 95% polydimethylsiloxane and 5% polydiphenylsiloxane (TBR-5) was employed to carry out on-line extraction and preconcentration of dibuthyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) in the chromatographic system. The coated capillary was placed between the sample injection loop and the injection needle of an autosampler. Variables affecting the automatic in-tube solid-phase microextraction (SPME) were optimized. A Genesis C_(18) (5 cm x 4.6 mm i.d., 4 mum particle size) was employed as analytical column. The achieved limits of detection by use of diode array detection were 1 and 2.5 mu gL~(-1), respectively. The proposed conditions have been applied to determine those compounds at low ppb levels (≤250 mug L~(-1)) in aqueous samples. No matrix effect was found, and recoveries between 85 and 115% were obtained. The precision of the method was good, and the achieved intra- and inter-day variation coefficients were between 5 and 20%. The analysis time per sample was 20 min and any off-line pre-treatment of the samples was needed. The taken sample volume was 100 muL. Data on the application of the described method to the analysis of different water samples are presented.