Determination of 14 nitrophenol products by SPE-ultra performance liquid chromatography

A simple ultra performance liquid chromatography (UPLC) method for the determination of fourteen nitrophenol residues in environmental waste water is proposed. A Bond Elut Plexa solid phase extraction (SPE) is used for the extraction and purification of the compounds in environmental waste water. The water sample with sampling amount of 5.0 mL is purified using a solid phase extraction column, and then eluted with 3.0 mL tetrahydrofuran. The elution is introduced into the instrument and determined by HPLC with photodiode array detector with detection wavelength of 220 nm. A good base line separation of target compounds is achieved within 22 minutes under the optimal condition. The calibration curves of 3 amides are linear in the concentration range of 0.1~20 mg/L with the correlation coefficients of 0.9973~0.9987. The recoveries are 82.5%~104.8%, and the relative standard deviations range from 3.2% to 5.7% for the target compounds. The minimum detectable concentrations are 0.02~0.04 mg/L. This proposed method is convenient to use, sensitive and accurate, and is suitable for the routine detection of trace amide contaminants in environmental waste water.