瑞丽地区2020年部分蔬菜农药残留情况及分析

为了解云南省瑞丽地区蔬菜农药残留情况,本研究采用气相色谱法对不同来源、不同品种的211个蔬菜样品中有机磷、有机氯、拟除虫菊酯类共42种农药残留进行定量分析检测。结果显示,在211个检测的蔬菜样品中,生产基地抽样163个,合格率为98.8%;批发市场抽样22个,合格率为95.5%;农贸市场和超市分别抽样11个、15个,合格率均为100%;总体合格率为98.58%。茄果类蔬菜农残检出率最高(41.5%),叶菜类检出农药种类最多(11种)。共检出禁限用农药甲胺磷、三氯杀螨醇、毒死蜱等6种,检出率最高的为毒死蜱和氧乐果(1.42%),检出非禁限用农药氯氟氰菊酯、氯氰菊酯、腐霉利、三唑酮等11种,检出率最高的为氯氟氰菊酯(9.00%)。

原子荧光法同时测定土壤中砷和汞前处理方法初探

文章建立一种新的土壤样品前处理方法,处理后可利用原子荧光法同时测定土壤中的砷和汞。样品采用硝酸、盐酸混合试剂加热消解,在优化的测量条件下,对石墨消解仪和水浴加热消解前处理方法检测比较,找到原子荧光法同时测定土壤中砷汞最佳的前处理方法。水浴消解法在80℃、150 min条件下,消解效果最好;石墨消解在80℃、180 min条件下,消解效果最好。砷准确度在91.8%~101%,RSD在0.20%~3.1%,汞准确度在97.0%~98.5%,RSD在3.9%~5.8%,满足土壤中砷汞测定要求。

Thermodynamic Study on Process in Copper Converters(The slag-making stage)

The so-called Goto's model was modified by introducing a parameter of the oxygen efficiency from industrial trials, as well as the selected and newly re-assessed thermodynamic data. The application of the model to copper converters in Guixi Smelter has been carried out by the combination of thermodynamic calculations with the mass and heat balance using the plant data obtained in industrial trials for many heats. For the slag-making stage, good agreements have been reached betWeen the calculated and measured temperature, blowing time as well as the contents for main elements in the matte and the slag. Relativel}'' large deviations for contents of Zn and Pb in the slag may be caused by the complex chemical composition of the real molten slag, which ma}; result in a large difference of γzn. and γPb,adopted with their real values. It is noted that the model can simulate the slag-making stage of copper converting process in industrial Pierce-Smith converters well.

瑞丽市2019年市售水果42种农药残留检测结果分析

为了解云南省瑞丽市水果农药残留情况,采用定量分析对不同来源、不同品种的109个水果样品中42种农药残留进行了检测。结果显示:1)在检测的109个水果样品中,生产基地抽取样品81个,合格率为96.30%;批发市场、农贸市场和超市分别抽取样品9个、9个和10个,合格率均为100%;总体合格率为97.25%。2)柑橘类水果农残检出率最高(11.93%),检出农药种类也最多(11种)。3)共检出农药9种,检出率最高的农药为毒死蜱(10.09%),氧乐果超标率高。