溴苯腈在小麦和土壤中的消解及安全性评价

目的研究溴苯腈在小麦和土壤中的消解趋势,评价溴苯腈在小麦上使用的安全性。方法样品经80:20(V:V)的乙腈和水提取,提取液用甲酸调节pH值,加氯化钠,用正己烷萃取,萃取液浓缩后用气相色谱质谱检测。结果麦苗中溴苯腈原始沉积量为7.13～51.56 mg/kg,半衰期1.3～2.3 d,2～7 d消解90%以上;土壤中溴苯腈原始沉积量为0.21～1.81 mg/kg,t_(1/2)为2.2～5.3 d,3～21 d消解90%以上。北京、安徽和山东3地麦粒、麦秆和土壤中溴苯腈的最终残留量在ND～0.024 mg/kg之间。结论我国规定溴苯腈在小麦上的最大残留限量为0.05 mg/kg,参照该标准,溴苯腈80%可溶性粉剂,按推荐剂量和方法在小麦上使用,收获时检测小麦样品,小麦中溴苯腈的残留量对人类的健康是安全的。

Dissipation dynamics and safety evaluation of bromoxynil in wheat and soil

Objective To investigate the dissolution trend of bromoxynil in wheat and soil and evaluate the safety of bromoxynil in wheat. Methods Samples were extracted by acetonitrile and water(80:20, V:V), the extractions were purified by hexane with adding sodium chloride after using formic acid to regulate pH, the purified liquids were concentrated and determined with GC-MS. Results The original deposit amounts of bromoxynil in wheat seedling ranged from 7.13 to 51.56 mg/kg. The half-lives of bromoxynil ranged from 1.3 to 2.3 d, and 2-7 d digestion of over 90%. The original deposit amounts of bromoxynil in soil ranged from 0.21 to 1.81 mg/kg. The half-lives of bromoxynil ranged from 2.2 to 5.3 d, and 3-21 d digestion of over 90%. The residues of bromoxynil in wheat grain, straw and soil were below 0.024 mg/kg when the harvest. Conclusion The residues of bromoxynil in wheat are below the maximum residue limit set by China (MRL, 0.05 mg/kg). With reference to this standard, when the bromoxynil 80% soluble powder is used in wheat according to the recommended dosage and method, the residual amount of bromoxynil in wheat is safe for human health.