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目的建立苹果中有机磷农药残留的自动顶空固相微萃取-快速气相色谱-质谱联用测定方法。方法用聚二甲基硅氧烷(PDMS)进行萃取,对萃取温度、萃取时间、离子强度、振荡频率和有机溶剂的比例进行了优化,采用进样口温度:250℃;离子源温度:230℃;接口温度:280℃;柱温为程序升温:初温40℃保持1min,以128℃/min升至130℃,以21℃/min升至250℃,以150℃/min升至300℃,保持1min;初始状态为不分流进样,1min后打开分流阀,分流比30︰1,质谱采用电子轰击离子源(EI),选择离子方式(SIM)检测,外标法定量。结果方法的最小检出限为0.002～0.955ng/g,相对标准偏差为1.80%～16.38%,回收率为82.7%～132.8%。结论样品处理简单,检测速度快,检出限较国标方法大大降低,可作为检测苹果中有机磷农药残留的有效方法。
Objective To establish an automated headspace solid-phase microextraction-rapid gas chromatography-mass spectrometry (GC-MS) method for the determination of organophosphorus pesticide residues in apples. Methods The extraction temperature, extraction time, ionic strength, oscillation frequency and ratio of organic solvent were optimized by using polydimethylsiloxane (PDMS). The inlet temperature was 250 ℃ and the temperature of ion source was 230 ℃; Interface temperature: 280 ℃; Column temperature for the program temperature: the initial temperature 40 ℃ for 1min, with 128 ℃ / min rose to 130 ℃, 21 ℃ / min rose to 250 ℃, 150 ℃ / min rose to 300 ℃ , And kept for 1 min. The initial state was splitless injection. After 1 min, the diverter valve was opened and the split ratio was 30: 1. The mass spectrometry was performed by electron impact ionization (EI), ion-selective mode (SIM) and external standard. Results The detection limit of the method was 0.002 ~ 0.955ng / g with relative standard deviation of 1.80% ~ 16.38% and recovery of 82.7% ~ 132.8%. Conclusion The sample processing is simple, the detection speed is fast, the detection limit is greatly reduced compared with the national standard method, which can be used as an effective method to detect organophosphorus pesticide residues in apple.