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通过均匀设计法安排试验,利用计算机回归分析科学地建立了三种邻苯二甲酸酯类物质———邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二丁酯(DBP)的峰面积与分流比、升温速率之间的非线性数学模型。由此建模分析得到了分流比和升温速率对三种分析物峰面积的不同影响效果,为科学确立三种分析物的色谱检测条件奠定了基础。 相似文献
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应用循环伏安法制备了nano-Pt/GC修饰电极,优化了铂微粒在电极表面的沉积条件,并用扫描电子显微镜(SEM)和在硫酸中的循环伏安曲线对其进行了表征,结果表明铂微粒较为均匀地分散在玻碳电极表面,粒径约为140nm,电极具有很大的比表面积.实验研究表明nano-Pt/GC修饰电极对甲酸电氧化的催化性能明显好于铂片电极,在该电极上甲酸正向扫描和反向扫描时的氧化峰电流分别是铂片电极上的4.37倍和3.49倍,有效地提高了金属铂的利用率,玻碳电极上铂微粒的最佳沉积条件为循环次数为100次、沉积速度为5mV/s. 相似文献
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以赊店老酒为研究对象,应用气相色谱-质谱联用技术(GC/MS)检测该白酒中的微量成分,用色谱峰面积归一化法测定其各组分的相对含量.共鉴定出52种成分,其中己酸乙酯(54.97%)、乳酸乙酯(33.67%)含量较高,还检测出微量的酸类、醇类和其他物质. 相似文献
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采用水蒸气蒸馏法提取了产自青海的白丁香花蕾的挥发油,应用GC/MS方法对其化学成分进行了分析,分离出47个色谱峰,鉴定了26个化合物,占总峰面积的88.7%,主要成分是丁香酚、丁香醇、石竹烯、苯乙醇等化合物。 相似文献
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建立了基质固相分散（MSPD）-氢火焰离子化检测器气相色谱法（FID/GC）测定甘蔗中痕量甲拌磷、特丁硫磷农药残留量的方法。用弗罗里硅土作固相吸附剂,石墨化碳黑净化,丙酮作为洗脱液,GC进行分析检测。结果表明：在0.80-3.2μg/mL和0.96-3.2μg/mL范围内,甲拌磷和特丁硫磷浓度与峰面积呈良好的线性关系;样品加标平均回收率为81.8%-86.0%,相对标准偏差（RSD）为4.3%-7.5%。 相似文献
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本文报道了四种多元醇及多元缩合醇的双三甲基硅烷三氟乙酰胺(即BSTFA)衍生物气相色谱(GC)分析方法;优选了硅烷化试剂及衍生反立条件;建立了GC分离并采用外标法对各组分进行了定量分析。 相似文献
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采用循环伏安法制备了Pt-Sn／GC电极,并用电化学方法研究了Pt-Sn／GC电极对乙醇的电催化氧化。实验结果表明：乙醇在Pt／GC电极和Pt-Sn／GC电极上均能自发氧化解离,产生强吸附中间体COad,而Sn的加入降低了COad在电极表面的吸附量和覆盖度,抑制了乙醇的自发氧化解离,提高了催化剂的活性;与Pt／GC电极相比,乙醇在Pt-Sn／GC电极上的起始氧化电位负移80mV,正向扫描氧化峰电位负移60mV,电流增大1倍。当沉积量为100r时,Pt-Sn／GC电极对乙醇的电催化活性最高。 相似文献
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目的：研究用毛细管气相色谱法测定牛奶中甜蜜素含量的分析方法,通过对沉降剂用量、酯化时间等条件的优化,降低方法的检出限。方法：利用甜蜜素（环己基氨基磺酸钠）在硫酸介质中与亚硝酸钠反应后生成环己醇亚硝酸酯,用正己烷萃取,并用气相色谱检测环己醇亚硝酸酯的含量。结果：甜蜜素的线性范围为0.05-0.4 mg/mL,方法检出限为2μg,加标回收率在99.4%-102.5%之间,RSD为1.4%。结论：该方法简便、快捷、准确度高、重现性好,方法检出限低,优于GB/T5009.97-2003法的4μg检出限。 相似文献
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Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco 总被引：2，自引：0，他引：2
Simple procedures for extraction and chromatographic determination ofdimethachlon residues in fresh tobacco leaves and cut-tobacco are described. The determination was carried out by capillary gas chromatography （GC） with electron capture detection （ECD） and confirmed by GC-MS. The mean recoveries and relative standard deviation （RSD） were 93.2%-112.9% and 3.5%-6.7%, respectively at levels ranging from 0.01 to 0.1 mg/kg. The limit of determination was 0.001 mg/kg. Tobacco samples in routine check were successfully analyzed using the proposed method. 相似文献
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奥扎格雷中DMF残留量的测定 总被引：1，自引：0，他引：1
建立了直接进样毛细管气相色谱法测定奥扎格雷中DMF残留量的方法。色谱柱为HP-FFAP石英毛细管柱,采用程序升温,载气为氮气,检测器为FID,以DMSO为溶剂。在上述色谱条件下,DMF的线性范围为1.76~15.84 mg/L,平均加样回收率为95.14%。此方法可用于测定原料药中DMF的残留量。 相似文献
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Yuan Liu Ewen E. D. Todd Qiang Zhang Jiang-rong Shi Xian-jin Liu 《Journal of Zhejiang University. Science. B》2012,13(7):525-532
In recent years, there were two reported outbreaks of food borne illness associated with melamine. The presence of melamine and its related compounds in milk, feed, and other foods has resulted in the need for reliable methods for the detection and accurate quantification of this class of contaminants. The sample pretreatment for melamine in a complex matrix usually involves a liquid extraction by a polar solvent, followed by a further clean-up with solid phase extraction. Analyses of melamine and related compounds are commonly carried out by liquid or gas chromatographic methods conjugated with mass spectrometry. Other innovative screening methods, which use antibodies, molecularly imprinted polymers, capillary electrophoresis, and gold nanoparticles, are also used to develop assays and biosensors to melamine. However, many of these methods have been hindered by matrix effects, the solubility of melamine-cyanuric acid complex, and background contamination. This article reviews recent developments for detecting melamine and discusses future directions. 相似文献
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通过电沉积的方法将钯纳米颗粒固定到Ag微电极上,制成了钯纳米颗粒修饰Ag微电极,并将此作为毛细管电泳的检测器测定了葡萄糖,探讨了检测电位、分离电位、缓冲溶液的pH值等条件的影响.该方法线性范围为4×10-5～2×10-4 mol/L和2×10-4～1×10-2 mol/L,线性相关系数分别为0.997 0和0.997 5,检出限为1×10-5 mol/L,该微电极表现出良好的稳定性和重现性,迁移时间和峰电流的相对标准偏差分别为2.6%和3.1%（n=8）,分别测定了2个健康人和2个糖尿病患者血清中的葡萄糖,所得结果与医院检测结果一致. 相似文献
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制备了电化学还原氧化石墨烯修饰碳纤维微盘电极（ER-GO-MCFE）,将此电极与毛细管电泳联用,对氧化石墨烯的电化学还原时间和电位、缓冲溶液的浓度和pH值、分离电压和检测电位等条件进行了优化。在最佳条件下,抗坏血酸的线性范围为1.0×10^-6～1.0×10^-5mol/L和1.0×10^-5～0.8×10^-3 mol/L,线性相关系数分别为0.9985和0.9998;当信噪比为3时,检测下限为6.5×10^-7 mol/L。将此电极用做毛细管电泳电化学检测的工作电极,实现了对饮料样品中的抗坏血酸的定性和定量检测。 相似文献
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该文利用毛细管气相色谱法测定了三种塑料食品包装材料中邻苯二甲酸二(2-乙基己基)酯(DEHP)的含量.该方法使用RTX-5为色谱柱,邻苯二甲酸二正辛酯(DNOP)为内标,FID为检测器,用内标标准曲线法定量.在优化的条件下,线性范围为0.035～0.560 mg/L,检出限为0.01 mg/L,相对标准偏差为0.14%～0.60%,加标回收率为99.8%～103.2%. 相似文献
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李荣毅 《鞍山师范学院学报》2011,13(6):41-43
建立了食用菌中10种农药残留量的气相色谱分析方法.样品用乙酸乙酯-正己烷（体积比1∶1）溶液提取,经HP-5石英毛细管柱分离后,采用GC-FPD同时测定10种农药残留量.10种农药在0.1～5 mg/L范围内,均有良好线性关系.相关系数r大于0.997,样品在3个添加水平时的回收率为82%～110%,相对标准偏差为4.1%～12.9%.检出限为0.02～0.03 mg/kg.方法简便、快速、净化效果较好,可同时满足进、出口食用菌中多种农药残留量的检测需要. 相似文献
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The use of loess as an earthen final cover material is promising in northwest China which has an arid and semi-arid climate. A full-scale testing facility with an area 30 m long by 20 m wide was constructed at the Xi’an landfill of municipal solid wastes to investigate the performance of an inclined capillary barrier cover. The cover consisted of a compacted loess layer underlain by a gravel layer. The testing facility was well instrumented for a gas permeation test and recording of the soil conditions in terms of volumetric water content, pore gas pressure, and soil temperature. Tests were performed to measure the gas permeability of the compacted loess before and after the planting of vegetation on the cover. The field measurements demonstrate that the capillary break at the fine/coarse soil interface allows the upper compacted loess layer to retain more water, and conversely reduces its gas permeability, which is favorable for reducing landfill gas emissions. When the degree of saturation of the compacted loess was greater than 85%, the gas permeability decreased significantly with a further increment in volumetric water content. The growth of vegetation roots tended to fill the large pores in the upper loosely-compacted loess, resulting in a decrease in gas permeability of one order of magnitude. The influence of soil clods in the compacted loess on gas permeability can be one to two orders of magnitude due to an increase in pore size and a decrease in tortuosity. 相似文献
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计算分析了焓相等和滞止焓相等情况下毛细管中R22节流特性参数及其变化规律．并将两种情况下所选取的毛细管与真实制冷系统毛细管比较。理论计算和实验结果都表明滞止焓相等才是毛细管绝热节流的基本特性,而绝热节流焓相等的理论不够准确。 相似文献