Determination of Pesticide Ethion by Linear Sweep Stripping Voltammetry

The presence of the pesticide ethion was determined using an electroanalytical method, i. e. , linear sweep stripping voltammetry at a hanging mercury drop electrode in the Britton-Robbinson buffer with pH = 8. 36, based on its reduction peak observed at - 690 mV following its alkaline hydrolysis. The experimental parameters, namely, the preconcentration potential, the preconcentration time, and the scan rate were investigated and - 300 mV （vs. Ag/ AgCl）, 270 s, and 100 mV/s were selected as the optimal values, respectively. The linear relationship between the peak current and the concentration was found to be in the range of 0.02-0. 16 mg/L, with a detection limit of 0.0087 mg/L. The proposed method was applied to the determination of ethion in spiked vegetable and fruit samples via a preextraction with anhydrous ethanol.

The effects of ultrasonic irradiation in combination with ozone on the reduction of residual ethion of tangerine (<i>Citrus reticulata</i>Blanco cv. Sai Nam Pung) fruit after harvest

Ethion residue removal efficiency using individual and combined effects of ultrasonication (US), ozonation (O3), ultrasonication and ozonation (US/O3) was investigated. A 1 mg·L-1 standard ethion was subjected to an ultrasonic irradiation (3W input power) device with different frequencies of 108, 400, 700, 1000 kHz, and to an ozone with a concentration of 200 mg· mL-1 with various exposure times (0, 15, 30, 45 and 60 minutes). Reduction of residual ethion was determined by gas chromatography with flame photometric detection (GC-FPD). It was found that 1000 kHz ultrasonic irradiation for 60 minutes was the most effective treatment for reducing ethion concentration. Additionally, ozone could reduce the concentration of standard ethion after 60 minutes of exposure. Ultrasonic irradiation in combination with ozone had a synergistic effect in reducing standard ethion concentration, with the highest rate occurring within the first 15 minutes. Ethion concentration was reduced to 75.43% after ultrasonic irradiation at 1000 kHz and ozone exposure for 60 minutes. The effectiveness of the combined scheme for reducing of ethion residues on tangerine was also determined by GC-FPD. The ethion residue on fresh tangerines after ultrasonic irradiation and ozone washing was reduced by 73.03% after 60 minutes. The present study demonstrates that ultrasonic irradiation and ozone exposure could be used to reduce ethion residues in treated tangerine in order to meet the Standards for Pesticide Residue Limits.

Fury+Ethion复配乳油防治棉铃虫药效试验

Ｆｕｒｙ＋Ｅｔｈｉｏｎ混合乳油是从国外引进的新型复配杀虫剂，为了了解其药效，１９９７年在本站进行室内、田间试验，现将结果报道如下：一、供试药剂１．Ｆｕｒｙ＋Ｅｔｈｉｏｎ乳油（Ｆｕｒｙ与Ｅｔｈｉｏｎ比为１５∶８５）２．２５％快杀灵乳油二、试验方法设Ｆｕ...

辣椒提取加工过程中三种有机磷类农药残留迁移规律分析

本研究采用气相色谱-质谱联用仪(GC-MS)检测不同产地辣椒及其生产过程各工段物料中毒死蜱、乙硫磷和三唑磷三种有机磷类农药残留,综合评估产品风险和污染来源,并对三种有机磷类农药残留在辣椒及辣椒提取过程中的迁移规律进行研究。结果表明,不同产地来源辣椒及辣椒提取物中三种有机磷类农药残留量不同,原料带入是辣椒提取物中三种有机磷类农药残留主要污染来源。在辣椒提取加工过程中,毒死蜱和乙硫磷主要迁移至辣椒红,三唑磷主要迁移至辣椒油树脂。通过加强辣椒原料中有机磷类农药残留控制,可以有效降低辣椒及其提取物中有机磷类农药残留量。

凤眼莲植物修复几种农药的效应

报道了凤眼莲修复水溶液中乙硫磷、三氯杀螨醇和三氟氯氰菊酯的效果及主要机理 .研究结果表明 ,10～ 11g凤眼莲可将 2 5 0 m L的 1mg/ L的乙硫磷、三氯杀螨醇和三氟氯氰菊酯消解速度分别提高 2 83.33%、10 6 .6 4%和 36 2 .2 3% % .其修复机理主要是凤眼莲吸收农药后在体内积累或进一步降解 ,贡献率分别达 6 9.2 8%、37.77%和 6 3.0 6 % % ,而其中乙硫磷和三氯杀螨醇消解量的约 6 0 %由积累作用造成 ,积累对三氟氯氰菊酯的消解也起了约 30 %的作用 .微生物的降解贡献率相对较小 ,分别占乙硫磷、三氯杀螨醇和三氟氯氰菊酯消解率的 19.72 %、13.93%和 15 .30 % .

线性扫描溶出伏安法测量栽培生药中的乙硫磷农药

乙硫磷本身没有电化学活性,而在强碱性条件下它的水解产物在汞电极上具有电化学活性,在pH8·3Britton-Robinson缓冲溶液中,可获得灵敏的还原峰,峰电位为-690mV(vs.Ag/AgCl)。峰电流与乙硫磷的浓度在0·02～0·16μg/ml范围内呈线性关系,检出限为0·0087μg/ml。该文还初步探讨了乙硫磷的电化学行为。