不同金属反离子对含高效氯氟氰菊酯微乳液形成规律及其稳定性的研究

将十二烷基苯磺酸盐和苯乙烯化苯酚聚氧乙烯醚按摩尔比1∶1混合后, 结合5种金属反离子配成增溶高效氯氟氰菊酯的载药微乳体系, 研究其在导电机理、相行为及热贮稳定性上的差异. 结果表明, K+和Na+的十二烷基苯磺酸盐易于形成O/W型微乳液, Li+次之, Ca2+和Mg2+的十二烷基苯磺酸盐, 不利于形成O/W型微乳液.     

Preconcentration sensitive determination of pyrethroid insecticides in environmental water samples with solid phase extraction with SiO2 microspheres cartridge prior to high performance liquid chromatography

Present study developed a new method for the sensitive determination of pyrethroid insecticides with solid phase extraction in combination with high performance liquid chromatography and UV detector. SiO₂ microspheres, a new SiO₂ based material, was investigated for the enrichment ability and applicability as the solid phase extraction sorbent. Four pyrethroid pesticides such as fenpropathrin, cyhalothrin, fenvalevate and biphenthrin were used as the target analytes. Parameters that maybe influence the extraction efficiency such as the eluent type and its volume, sample flow rate, sample pH, and the sample volume were optimized in detail, and the optimal conditions were as followed: sample volume, 100 mL; concentration of methanol, 30%; acetone volume, 5 mL; sample flow rate, 4.2 mL min⁻¹; sample pH, 7. The experimental results indicated that there was good linearity in the concentration range of 0.1–50 μg L⁻¹ except biphenthrin in the range of 0.05–25 μg L⁻¹. The detection limits for fenpropathrin, cyhalothrin, fenvalevate and biphenthrin were in the range of 0.02–0.08 μg L⁻¹. The intra-day and day to day precisions (RSDs, n = 6) were in the ranges of 2.6–4.4% and 5.3–7.2%, respectively. The method was validated with five real environmental water samples, and all these results proved that proposed method could be used as a good alternative for the routine analysis for such pollutants in environmental samples.     

三氟氯氰菊酯分子印迹固相萃取膜的制备及其在食品检测中的应用

以三氟氯氰菊酯为模板分子、二甲基丙烯酸乙二醇酯为交联剂、乙腈为致孔剂,采用原位聚合技术制备分子印迹固相萃取膜,并对其性能和应用进行研究。采用紫外光谱法研究了功能单体的选择和其与三氟氯氰菊酯的最佳浓度比;使用三氟氯氰菊酯分子印迹膜对样品中拟除虫菊酯类农药残留进行富集和净化,并采用高效液相色谱法检测。结果表明,该分子印迹固相萃取膜对样品中拟除虫菊酯类农药有很强的特异性吸附作用,富集和净化效果好;三氟氯氰菊酯和联苯菊酯的检出限为0. 01μg/m L,胺菊酯、高效氯氰菊酯、四氟甲醚菊酯和氰戊菊酯的检出限为0. 05μg/m L,样品加标平均回收率为83. 4%~95. 9%,相对标准偏差为1. 45%~3. 76%(n=5)。该方法操作简单,灵敏度高,结果准确可靠。     

SPE-RP-HPLC法测定羊肉组织中胺菊酯和三氟氯氰菊酯残留量

建立了羊肉组织中胺菊酯和三氟氯氰菊酯的固相萃取-反相高效液相色谱测定法。采用氟罗里硅土固相萃取柱(1000 mg/6 mL)进行固相萃取。以Shim-pack VP-ODS(200 mm×4.6 mm)柱为分析柱,流动相为甲醇:水=95:5(V/V),流速为0.7 mL/min。胺菊酯和三氟氯氰菊酯分别在0.01～6.40μg/mL(r=0.9999)和0.068～7.20ug/mL(r=0.9998)范围内与峰面积呈良好线性关系,检出限分别为0.001μg/mL和0.002μg/mL,胺菊酯和三氟氯氰菊酯的回收率为90.2%～101.4%,相对标准偏差为2.3%～4.0%。该方法可作为羊肉组织中胺菊酯和三氟氯氰菊酯含量监测的控制方法。     

不同因素对高效氯氟氰菊酯微乳液相图的影响

通过电导率的测定研究了高效氯氟氰菊酯微乳液的结构及结构转变, 绘制了不同条件下高效氯氟氰菊酯微乳体系的拟三元相图, 讨论了十二烷基苯磺酸钠(SDBS)摩尔分数、电解质浓度、温度等因素对各类型微乳区形成的影响. 结果表明: ①随着SDBS摩尔分数增大, W/O型微乳区面积先减小后增大, BC和O/W型面积先增大后减小; ②随着电解质浓度增大, W/O、BC和O/W型微乳区面积均先增大后减小; ③随着温度升高, W/O型微乳区面积增大, BC和O/W型面积均减小.     

Sensitive Molecularly Imprinted Fluorescence Determination of Pyrethroids using Green Zinc Oxide Quantum Dots

Pyrethroids are similar to the natural pyrethrins produced by the flowers of pyrethrums that are effective insecticides but with potential toxicity. Here, a novel core–shell fluorescence probe for pyrethroids was prepared by precipitation polymerization. ZnO quantum dots and cyhalothrin were used as the substrate and template, respectively. Due to the formation of reversible specific recognition sites during copolymerization in the presence of acrylamide and ethyl glycol dimethacrylate, ZnO-based molecularly imprinted polymers containing cyhalothrin recognition sites were obtained. Transmission electron microscopy, infrared spectroscopy, and fluorescence spectroscopy were used to characterize the resulting ZnO-based imprinted polymers. The polymer microspheres were used to sensitively and selectively determine cyhalothrin. In addition, a linear relationship between the concentration of cyhalothrin and the fluorescence intensity was obtained from 0 to 80 µmol L^?1 with a correlation coefficient of 0.9964 using the Stern–Volmer equation. The protocol was used for the determination of cyhalothrin in milk demonstrating the suitability of the methodology for practical sample analysis. The selective and sensitive fluorescence recognition, low production cost, and facile synthesis demonstrate attractive properties of ZnO-based molecularly imprinted polymers for specific molecule recognition.     

Sensitive determination of fenpropathrin, cyhalothrin and deltamethrin in environmental water samples using multiwalled carbon nanotubes cartridge prior to HPLC

This paper described a new method for the trace determination of fenpropathrin, cyhalothrin and deltamethrin using multiwalled carbon nanotubes （MWCNTs） cartridge. Important parameters, such as the sample pH, eluent and its volume, sample flow rate and sample volume were investigated in detail. The linear ranges, the detection limits, and precisions （R.S.D.） were in the range of 0.1- 40 μg L^-11, 1.34.3 ng L^-1 and 2.3-2.8%, respectively. The performance of the proposed method was validated with real water samples, and the spiked recoveries were in the range of 91.7-117.8%, respectively. The experimental results demonstrated that the proposed method was an excellent alternative for the routine analysis of such pollutants in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

三氟氯氰菊酯农药中微量杂质的液相色谱－质谱法鉴定

用高效液相色谱－质谱联用技术研究了三氟氯氰菊酯农药的杂质及含量,并用源内碰撞诱导解离（CID）技术鉴别了所存在的微量杂质。方法实用性强,色谱分离效果好,可用于该农药各成分的定性、定量分析。     

应用GC-MS测定葡萄中的5种农药残留

酿酒葡萄是河北昌黎的主要水果种植品种,由于受海洋气候的影响,当地空气湿热,葡萄病害十分严重,因而农药使用十分频繁,为了评价其农药残留水平,我们采用丙酮提取,凝胶分离,硅胶小柱净化,GC-MS的选择离子方式检测对采集的葡萄样品进行5种农药(百菌清、精甲霜灵、苯醚甲环唑、嘧菌酯、高效氯氟氰菊酯)的残留分析。