Determination of Three Nitrophenol Compounds in Soil by Ultrasonic Extraction-High Performance Liquid Chromatography-Mass Spectrometry

As important organic chemical raw materials, nitrophenol compounds have high toxicity and carcinogenicity, which can be transmitted into soil through air and water, causing pollution and endangering human health. In the past, nitrophenol compounds in soil were usually determined by gas chromatography and gas chromatography-mass spectrometry. The derivatization was usually required to improve the sensitivity, which was time-consuming and cumbersome. To achieve a rapid and accurate analysis of the three nitrophenol compounds in soil, a method of ultrasonic extraction-high performance liquid chromatography-mass spectrometry (HPLC-MS) was established. The nitrophenol compounds in soil were extracted by ultrasonic extraction with dichloromethane/n-hexane (2∶1, V/V), and a strong alkaline aqueous solution (pH>12) was added to the ultrasonic extraction solution to remove the underlying organic phase. After the aqueous solution was adjusted to acidity (pH<2), three nitrophenol compounds were extracted with dichloromethane-ethyl acetate (4∶1, V/V). The extraction solution was concentrated and diluted to 10.0mL with 10% acetonitrile aqueous solution, and then determined by HPLC-MS. The RSDs of three nitrophenol compounds were less than 10.0%, detection limits were 0.1−0.2μg/kg, and the recoveries were 61.7%−90.8%. This method has the advantages of simple pretreatment and low detection limit, and can be applied to the determination and evaluation of nitrophenol compounds in soil.