不同因素对糙皮侧耳子实体和培养料中多菌灵残留富集及消解规律影响

采用超高效液相色谱(UPLC)-二极管阵列检测器(PDA)和液相二级质谱(LC/MS/MS)方法测定多菌灵在添加浓度范围分别为0.025~1 mg/kg和0.05~10 mg/kg 时在糙皮侧耳(Pleurotus ostreatus)子实体和培养料中的残留量,结果表明：多菌灵在子实体和培养料中的平均添加回收率分别为93%~99%、93%~101%,相对标准偏差(RSD)均为3%~6%。在0.1%、0.3%多菌灵有效成分用量下拌料施用后,糙皮侧耳第一和第五潮菇(菇柄、菇盖和全菇)中多菌灵残留量分别为0.089~0.077、0.533~0.485 mg/kg,低于欧盟关于多菌灵在新鲜菇类中的最大残留限量标准。多菌灵在子实体各个部位的富集能力由强到弱为菇脚>菇柄>全菇>菇盖。培养料中多菌灵的消解符合一级动力学模型,菌袋部位、菌丝和灭菌对培养料中多菌灵消解均有影响：菌袋上部(距离栽培袋底部22 cm处)的培养料中的多菌灵消解快,半衰期33 d短于中部(距离栽培袋底部11 cm处)的36.47 d和下部的63 d；培养料中菌丝生长有利于多菌灵消解,高压灭菌(0.1 Mpa 压力下,121℃灭菌2 h)可以有效地促进农药消解。灭菌后降解率达91.8%和85.9%,未灭菌时培养料中多菌灵含量基本稳定。

Effects of Different Factors on Carbendazim Residue Accumulation and Dissipation in Cultivation Substrate and Fruit Body of Pleurotus ostreatus

Carbendazim accumulation and dissipation in P.ostreatus fruit bodies and cultivation substrate were analyzed separately by UPLC-PDA and LC/MS/MS,respectively.Residual levels of carbendazim in the first and fifth flush of mushroom fruit bodies grown on substrate treated with 0.1% and,0.3% pesticide ranged from 0.089-0.077 mg/kg and 0.533-0.485 mg/kg respectively,which were below the EU maximum allowable concentration of 1 mg/kg.Accumulation of carbendazim in different parts of mushroom fruit bodies varied considerably with levels in the stipe base>stipe>whole fruit body>pileus.Carbendazim dissipation in the cultivation substrate followed first order kinetics and was affected by the stratum within the culture bag,the presence of fungal mycelium and sterilization.Carbendazim levels in the upper stratum of the culture bag (22 cm from the bottom of the bag)decreased more rapidly with a half-life of 33 d compared with 36.5 d and 63 d for the middle and lower stratum.Higher dissipation rates were also recorded in substrates inoculated with P.ostreatus and sterilized at high pressure (0.1 Mpa,121 ℃,2 h).