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样品现代前处理技术在农药残留分析中的应用 总被引:10,自引:0,他引:10
本文介绍了样品现代前处理技术加速溶剂萃取(ASE)、超临界流体萃取(SFE)、固相萃取(SPE)、固相微萃取(SPME)、凝胶渗透色谱(GPC)的原理及其在农药残留分析中应用情况。 相似文献
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几种分离技术在农药残留分析中的应用 总被引:2,自引:0,他引:2
本文介绍了样品现代前处理技术加速溶剂萃取(ASE)、超临界流体萃取(SFE)、固相萃取(SPE)、固相微萃取(SPME)、凝胶渗透色谱(GPC)的原理及其在农药残留分析中应用情况。 相似文献
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本文综述了利用超临界流体萃取技术萃取并通过气相、液相、紫外、红外、超临界流体色谱等技术对农药残留进行检测的发展。 相似文献
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超临界流体萃取技术在农药残留分析中的应用进展 总被引:12,自引:2,他引:12
从萃取过程控制的角度,综述了近几年来国外超临界流体技术不同形态的基体的农药残留分析中的应用情况、研究现状及前景。 相似文献
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砂地柏果实油杀虫成分松油烯-4-醇的超临界流体萃取 总被引:1,自引:0,他引:1
采用超临界流体萃取-气相色谱法,以砂地柏Sabina vulgaris Ant.果实油主要杀虫活性成分松油烯-4-醇的萃取率为评价指标,提出了砂地柏果实油中松油烯-4-醇的超临界流体萃取较优工艺条件为:萃取物料粒径0.85 mm(20目),静态萃取10 min,萃取温度45℃,压力34.47 Mpa,流体CO2总流量30 mL/g。采用该法对砂地柏果实油中松油烯-4-醇的萃取率达2.72 mg/g,明显高于水蒸气蒸馏法(萃取率为2.00 mg/g),并具有快速、简便、精确、无毒、经济等优点。 相似文献
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超临界流体提取技术与农药残留分析 总被引:9,自引:2,他引:7
本文介绍超临界流体提取技术在农药残留分析中的应用,超临界流体提取技术的主要优点是取时间短,耗费有机溶剂少和提取条件可控制,它克服了溶剂提取的缺点,提取效果接近索氏法,已经成为一种优秀的样品制备技术,农药残留分析中采用这一技术具有很有价值的。 相似文献
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采用超临界流体萃取-反相高效液相色谱法,以鱼藤酮萃取率和萃取产物总得率为评价指标,研究提出非洲山毛豆Tephrosia vogelii Hook.f中鱼藤酮的超临界流体萃取较优工艺条件为:萃取物料粒径30目,静态萃取20 min,萃取温度45℃,压力27.58 MPa,流体总流量30 mL/g,萃取前向萃取池中加入3 mL甲醇作夹带剂。采用该法对非洲山毛豆中鱼藤酮的萃取率(质量分数)达0.41%,相当于氯仿浸提法的98%;萃取产物总得率(质量分数)为16.62%,高于氯仿浸提法。与常规溶剂法相比,该方法具有萃取效率高、精确、无毒、经济、操作简便、选择性可调等优点。 相似文献
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近年来,一批高新技术(如膜分离技术、超临界流体萃取技术等)在食品工业中得到应用和推广,促进了食品工业的发展,使部分产品的品质得到较大的提高。这些技术在茶叶加工中的应用研究也日益得到重视,部分技术已取得了良好的应用效果。本文就这些新技术的基本原理及其在茶叶加工中的应用状况作一综述。 相似文献
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农药残留分析中的提取新技术 总被引:31,自引:0,他引:31
本文介绍了近些年来, 农药残留检测分析中的加速溶剂提取法(ASE) 、微波加热提取法(MAE) 、超临界流体提取法(SFE)、微型固相提取法(SPME) 等一些新的提取技术的特点。 相似文献
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Tomas Berglf William C Koskinen Henrik Kylin Thomas B Moorman 《Pest management science》2000,56(10):927-931
Sorption–desorption of the fungicide triadimefon in field‐moist silt loam and sandy loam soils were determined using low‐density supercritical fluid extraction (SFE). The selectivity of SFE enables extraction of triadimefon from the soil water phase only, thus allowing calculation of sorption coefficients (Kd) at field‐moist or unsaturated conditions. Triadimefon sorption was influenced by factors such as soil moisture content and temperature; sorption increased with increased moisture content up to saturation, and decreased with increased temperature. For instance, Kd values for triadimefon on the silt loam and the sandy loam soils at 40 °C and 10% water content were 1.9 and 2.5 ml g−1, respectively, and at 18% water content, 3.3 and 6.4 ml g−1, respectively. Isosteric heats of sorption (ΔHi) were −42 and −7 kJ mol−1 for the silt loam and sandy loam soils, respectively. Sorption–desorption was also determined using an automated accelerated solvent extraction system (ASE), in which triadimefon was extracted from silt loam soil by 0.01 M CaCl2. Using the ASE system, which is basically a fast alternative to the batch equilibration system, gave a similar ΔHi value (−29 kJ mol−1) for the silt loam soil (Kf = 27 µg1 − 1/n ml1/n g−1). In order to predict transport of pesticides through the soil profile more accurately on the basis of these data, information is needed on sorption as a function of soil water content. © 2000 Society of Chemical Industry 相似文献
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Extraction of pesticides from river water samples using the classical liquid-liquid extraction (LLE) approach is a labour-intensive procedure that requires relatively large volumes of solvent. With the solid-phase extraction (SPE) technique using membranes, the volumes of solvent are reduced. However, it is necessary to pre-filter and often also to acidify the river water to pH < 2 to prevent plugging of the capillary pores. This low pH may decompose some pesticides and therefore a fast and inexpensive technique with bulk sorbent and without prefiltration and acidification was developed. To reduce the solvent volumes further, extractions of discs and bulk sorbent were performed with supercritical fluids (SF). Seven pesticides with different polarities were studied. Mean recoveries from the bulk sorbent and the discs were of the same order (61%). However, recoveries from the latter improved to 82% with SFE of the discs, providing results comparable to LLE (94%) recovery. 相似文献
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助剂对10%苯醚甲环唑水分散粒剂在荔枝叶片表面润湿性能的影响 总被引:3,自引:0,他引:3
采用接触角测量仪测定了10%苯醚甲环唑水分散粒剂 (difenoconazole WG) 不同倍数稀释液在荔枝叶片上的静态接触角和0~60 s动态接触角,用于计算荔枝叶片的临界表面张力和表面自由能,进而分析药液在荔枝叶片表面的润湿性能;采用全自动张力仪测定了在10%苯醚甲环唑WG不同稀释液中分别添加体积分数为0.4%的silwet stik和0.2%的as 100 2种助剂后溶液的表面张力,研究了助剂添加前后表面张力的变化。结果表明:荔枝叶片近轴面的表面自由能为23.74 mJ/m2,远轴面的表面自由能为11.89 mJ/m2,均以色散力分量 (非极性分量) 为主导。在10%苯醚甲环唑WG 500倍稀释液中加入体积分数为0.4%的silwet stik溶液,其表面张力为21.90 mN/m,低于荔枝叶片的临界表面张力 (22.64 mN/m),且在0~10 s内接触角下降最快。研究结果表明:荔枝叶片的近轴面比远轴面更易被药液润湿;在荔枝园喷施10%苯醚甲环唑WG时,若在稀释倍数500倍的药液中添加0.4%的silwet stik助剂,则可使药液在叶片上能更快更好的润湿铺展。 相似文献