测试砂糖桔黄龙病综合防治新技术中,果实及生态土壤里10种有机磷农药的残留量是否符合食品安全标准,为推广应用砂糖桔黄龙病的防治新技术,惠及果农提供可行性的科学依据.对患黄龙病的砂糖桔果树用适量有机磷喷洒枝叶,同时用一种抑虫、杀菌、营养的混合物质对其树干进行定量滴注.采集防治不同次数的果树上结的果实及树根周围的土壤为测试对象,样品用乙腈超声提取,取上清液,经 Florisil柱萃取,丙酮-正己烷(20:80)洗脱,残渣用正己烷溶解,合并萃取液.所有样品提取液过0.22 μm滤膜后用气相色谱测定.10种有机磷农药在所建立的色谱条件下,26 min内能完全分离,在0.05~0.50 μg/mL范围内线性关系良好,相关系数均大于0.999,回收率在85.13 %~108.79 %,精密度RSD<2.98 %.砂糖桔中均未检测到有机磷农药残留,土壤样品中除检测出乐果和毒死蜱含量均小于80 μg/kg外,其余8种有机磷农药均未被检测出来.砂糖桔样品中10种有机磷农药均未被检测出来,符合食品安全要求;土壤中检测出少量乐果和毒死蜱,但未超过国家食品标准(GB 2763-2016)中有机磷农药最大残留量浓度:毒死蜱<1 mg/kg,乐果<2 mg/kg.因此,我们认为此砂糖桔黄龙病综合防治新技术值得推广应用.%To determine whether the contents of organophosphorus pesticide residue in Shatangju(Citrus reticulate Blanco cv.Shatangju)and ecological soil meet the food safety standard, and provide the scientific basis for promoting the application of new Huanglongbing (HLB) prevention, benefiting the farmers for the feasibility. In this experiment, Organophosphorus Pesticide Residues were sprayed to branches and leaves. At the same time, a kind of insecticidal, bactericidal and nutritive mixture was used to make a quantitative drip of the tree trunk. The fruit and soil samples controlled for different times were collected, and ultrasonically extracted with acetonitrile. Then, the supernatant of fruit and soil was purified by Florisil column and eluted with acetone-n-hexane (20:80), respectively. The solutions were filtered through a 0.22 μm filter membrane and analyzed by gas chromatography. In the established chromatographic conditions, 10 kinds of organophosphorus pesticides could be completely separated in 26 minutes with a good linearity (0.05~0.50 μg/mL). The correlation coefficients were more than 0.999, the recovery ranged from 85.13 % to 108.79 %, the RSD of precision was less than 2.98 %. No organophosphorus pesticide residues were detected in the fruit samples, dimethoates and chlorpyrifos were detected in the soil samples less than 80 μg/kg. 10 kinds of organophosphorus pesticides in the fruit samples were not detected, and fitting the food safety requirements. Small amounts of dimethoate and chlorpyrifos were detected in the soil samples, but meeting the required concentration of maximum organophosphorus pesticides residue of national food standard (GB 2763-2016): chlorpyrifos less than 1 mg/kg, dimethoate less than 2 mg/kg. The result shows that this method was worth popularizing.
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