Abstract: Myclobutanil is regarded as a fungicide against Panax notoginseng round spot and black spot disease with good application prospect. The method for the determination and residue dynamics of myclobutanil in P. notoginseng has not been reported. In order to establish the method for the determination and residue dynamics of myclobutanil in P. notoginseng, the residue dynamic of myclobutanile in root, stem, leaf of P. notoginseng and its soil were studied by HPLC-MS, moreover the dietary safety and risk assessment were conducted based on the field trial data. The samples were separated by acetone, purified by SPE solid phase extraction, separated on a BEH-C18 column (2.1 mm×50 mm, 1.7 μm), eluted with 70∶30 acetonitrile aqueous solution as the mobile phase. Quantitative analysis was performed using positive ion scanning and multi-reaction monitoring. The content of saponins in P. notoginseng root was determined by high performance liquid chromatography (HPLC). The fortified recovery rate at level of 0.1～5.0 mg/kg ranged from 80.9%～91.9%, with relative standard deviation of 5.05%～9.3%, and the limit of quantification for myclobutanil in P. notoginseng is 0.1 μg/kg. The results showed that the decline of myclobutanil in P. notoginseng and soil followed the first-kinetic equation. The half-life of myclobutanil in P. notoginseng root, stem, leaf and soil was 6.77 d, 6.70 d, 6.63 d, and 6.03 d, respectively, when the spaying dosage was 135 g/hm2. The risk quotient was 9.5×10-5, which was much less than 1, suggested the risk was very low with a safe level. With the development of P. notoginseng, the contents of notoginsenoside Rg1 and notoginsenoside Rb1 were increasing. It was suggested that the maximum residual value of myclobutanil in P. notoginseng could be set at level of 0.2 mg/kg and the safety interval were 35 d. The results showed that myclobutanil was safe for use in controlling diseases in P. notoginseng.

Key words: myclobutanil, Panax notoginseng, soil, residue dynamic

摘要： 腈菌唑（myclobutanil）被认为是防治三七黑斑病和圆斑病等病害应用前景较好的杀菌剂，但其在三七中残留检测和残留消解动态研究尚未见报道。为建立三七中腈菌唑残留检测和残留消解动态的检测方法，利用高效液相色谱-质谱联用技术（HPLC-MS）研究40%腈菌唑可湿性粉剂在三七（Panax notoginseng）根、茎、叶和土壤中的消解动态及喷施前后的皂苷含量变化，并对其可能产生的膳食安全风险进行评估。三七样品经丙酮提取，SPE固相萃取柱净化后，再由BEH-C18色谱柱(2.1 mm×50 mm，1.7 μm)分离，以体积比为70∶30的乙腈水溶液为流动相进行洗脱，利用正离子扫描，多反应监测进行定量分析，外标法定量；采用高效液相色谱法测定三七块根中主要皂苷成分的含量。结果表明，建立的三七中腈菌唑残留量检测方法在0.1～5.0 mg/kg水平的平均添加回收率为80.9%～91.9%，相对标准偏差为5.05%～9.3%，腈菌唑检测极限为0.1 μg/kg。在大棚内喷施135 g/hm2的腈菌唑时，在三七及土壤中的降解过程均符合一级动力学方程，腈菌唑在三七根、茎、叶和土壤中的降解半衰期分别为 6.77 d、6.70 d、6.63 d和6.03 d，其风险商值为9.5×10-5，远小于1，风险较低，处于安全水平；随着生育期的增加，三七根中人参皂苷Rg1、人参皂苷Rb1的含量不断增加。因此，建议我国腈菌唑在三七中的最大残留量值可暂定为0.2 mg/kg，安全间隔期为35 d。研究结果表明腈菌唑对三七使用安全，为腈菌唑在三七上的安全合理使用提供科学依据。

关键词: 腈菌唑, 三七, 土壤, 消解动态