多效唑在桃果实中残留研究

Study on residue of paclobutrazol in peach fruits

【目的】为了解桃树使用多效唑后果实中的残留量,【方法】利用气相色谱-三重四级杆串联质谱仪(GC-MS-MS)对多效唑在桃果实中的残留消解动态和最终残留量进行了测定和研究。【结果】结果表明,多效唑在桃果实中消解半衰期约为8.5 d。在桃上喷施1～2次1 000～1 500 mg·L-1多效唑(喷施2次间隔36 d)后30 d,桃果实中的多效唑残留量低于0.5 mg·L-1,推测其安全间隔期为30 d。【结论】多效唑在桃果实中半衰期较短,降解速度较快。以0.5mg·kg-1为限量标准,多效唑在桃生产中施用浓度不高于1 500 mg·L-1,使用次数不多于2次,末次施药离采收30 d以上,对人类安全。

【Objective】In order to evaluate the residue of paclobutrazol in peach fruit after its application,【Method】the degradation dynamics and the terminal residues of paclobutrazol in fruit were determined and investigated by gas chromatography-triple quadrupole mass spectrometry from 2010 to 2011.【Result】Results showed that the degradation half-life of paclobutrazol in fruit was about 8.5 days.Residue of paclobutrazol in peach fruit was below 0.5 mg·kg-1 on the thirtieth day after 1 000 to 1 500 mg·L-1 of paclobutrazol was sprayed 1 to 2 times on peach trees,which suggested that the safety interval was 30 days.【Conclusion】The degradation speed of paclobutrazol in peach fruit is relatively fast.According to MRLs≤0.5 mg·kg-1 in peach fruit,it is safe to human being when no higher than 1500 mg·L-1 of paclobutrazol is sprayed 1～2 times on peach trees before 30 days to harvest.