建立了红外光谱法测定肥料中石油烃总量的方法。称取肥料样品5 g，用15 mL体积比1∶1的二氯甲烷-丙酮混合液在超声功率80%（最大功率800 W）条件下，提取18 min，提取2次，合并2次上清液于35℃浓缩至近干，用20 mL四氯化碳溶解残渣。所得溶液转移至固相萃取小柱中，用5 mL四氯化碳进行洗脱，收集洗脱液，采用红外光谱法进行测定。结果表明，石油烃的质量浓度在5.0~500.0 mg·L^-1内与其对应的峰面积呈线性关系，检出限（3s）为5.0 mg·kg^-1。对3种肥料样品进行加标回收试验，结果得石油烃总量为123~1 515 mg·kg^-1，石油烃的回收率为84.0%~93.2%，测定值的相对标准偏差（RSD，n=6）为0.92%~4.3%。

A method for the determination of total petroleum hydrocarbons by infrared spectroscopy was established. The fertilizer sample of 5 g was extracted for 18 min with 15 mL of a mixture of dichloromethane and acetone at volume ratio of 1∶1 under 80% ultrasonic power (maximum power 800 W). The extraction was carried out twice, and the combined supernatant was concentrated to nearly dry at 35 ℃. The residue was dissolved with 20 mL of carbon tetracloride. The solution was transferred to solid phase extraction column and eluted with 5 mL of carbon tetracloride. The eluent was collected and determined by infrared spectroscopy. As shown by the results, linear relationship between mass concentration of total petroleum hydrocarbons and its peak area was kept in the range of 5.0-500.0 mg·L^-1, with detection limit (3s) of 5.0 mg·kg^-1. Recovery test was made on the 3 fertilizer samples by standard addition method, giving results of the amount of total petroleum hydrocarbons in the range of 123-1 515 mg·kg^-1, and recovery were in the range of 84.0%-93.2%, with RSDs (n=6) of the determined values ranged from 0.92% to 4.3%.