排序方式: 共有39条查询结果,搜索用时 62 毫秒
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利用微型固相萃取柱对样品进行前处理,采用胃袋式大体积进样技术结合气相色谱-质谱(GC-MS),建立了菠菜中13种有机磷农药残留的同时快速分析方法。以保留时间和特征离子丰度比定性,以峰面积外标法定量,以3倍信噪比实验值确定方法的检出限(LODs),以10倍信噪比实验值确定方法的定量限(LOQs)。结果表明,除乐果外,其余12种有机磷农药的添加回收率为76.8%~114.0%,相对标准偏差为1.5%~17.6%,LODs为0.5~25 μg/kg。该方法前处理简单快速,分析成本低,分析时间短,灵敏度、准确度和精密度均符合农药多残留检测技术的要求,适用于食品中多种有机磷农药残留的快速灵敏检测。 相似文献
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粮谷和油籽中丰索磷残留量的气相色谱及气相色谱/质谱分析 总被引:3,自引:0,他引:3
介绍应用气相色谱和气相色谱-质谱法测定及确证粮谷和油籽中丰索磷的残留含量,试样采用水-丙酮提取,提取液经液-液分配后,再以弗罗里硅土柱净化,气相色谱,火焰光度检测器测定,外标法定量,并用气相色谱-质谱针对丰索磷的选择监测离子的种类和丰度比进行敢阳性确证。 相似文献
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Hongxia Chen Daning Shi Jingshan Qi Baolin Wang 《Physica E: Low-dimensional Systems and Nanostructures》2009,42(1):32-37
We investigate the energetic, electronic, and mechanical properties of the pristine, hydrogen, and water adsorbed ZnS nanowires using the all-electron density functional theory. We found that water adsorption is energetically favorable and makes the band gap change from indirect to direct for the smallest nanowire. The Young's moduli of the pristine and water adsorbed nanowires are larger, but those of the hydrogen adsorption nanowires are smaller than that of bulk ZnS. The physical origin of the different tendencies can be attributed to the different surface relaxations of three kinds of ZnS nanowires. 相似文献
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采用电量法和失重法,测定了裸洁Al电极在不同浓度、温度和PH值的聚丁二烯酸(PBA)溶液中阳极溶解速度,确定了电活性Al(Ⅲ)离子的最佳形成条件及其对PBA的凝聚作用规律.结果表明,在60℃温度,pH=3.0的0.6mol·L-1柠檬酸+1.0g·L-1PBA溶液中产生的电活性铝离子对水溶性不饱和高分子低聚物的凝聚作用最强.简单讨论了这一电凝聚作用的机理. 相似文献
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In the present article, the use of slave-boson mean-field theory of the extended Anderson lattice model has been generalized to the Nambu space. The Green's functions of heavy fermion superconductors (HFS) have been obtained. The high sensitivity of the d-wave pairing HFS to the nonmagnetic impurities has been studied. The obtained results are in good agreement with the recent experiments on HFS. 相似文献
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We study the electron transport properties of graphene anti-dot and periodic graphene anti-dot arrays using the nonequilibrium Green?s function method and Landauer–Büttiker formula. Fano resonant peaks are observed in the vicinity of Fermi energy, because discrete states coexist with continuum energy states. These peaks move closer to Fermi energy with increasing the width of anti-dots, but move away from the Fermi energy with increasing the length of anti-dots. When N periodic anti-dots exist in the longitude direction, a rapid fluctuation appears in the conductance with varying resonance peaks, which is mainly from the local resonances created by quasibound state. When P periodic anti-dots exist in the transverse direction, P-fold resonant splitting peaks are observed around the Fermi energy, owing to the symmetric and antisymmetric superposition of quasibound states. 相似文献
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黑加仑籽油中脂肪酸成份的研究 总被引:4,自引:0,他引:4
本文系统地报道了应用GC、GC/MS技术剖析黑加仑油的主要成份,并与含有γ-亚麻酸的几种野生植物油的脂肪酸成份进行对照。本研究有助于我国黑加仑资源的进一步开发和利用。 相似文献
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气相色谱-质谱联用法测定动物组织中氯霉素、氟甲砜霉素和甲砜霉素的残留量 总被引:27,自引:0,他引:27
建立了气相色谱-负离子化学电离源质谱同时测定动物组织中氯霉素(CAP)、甲砜霉素(TAP)和氟甲砜霉素(FF)残留量的方法。样品用乙酸乙酯提取,正己烷分配去脂肪,再用Florisil柱进一步净化,甲苯作为反应介质,用N,O-双(三甲基硅基)三氟乙酰胺(BSTFA)-三甲基氯硅烷(TMCS)(体积比为99∶1)进行硅烷化处理,用间硝基氯霉素(m-CAP)作为内标进行测定。CAP的检测限可达到0.03 μg/kg,TAP和FF的检测限可达到0.2 μg/kg;上述3种药物的标准曲线的线性相关系数均大于0.99。CAP,FF和TAP的批内测定的精密度(以相对标准偏差表示)依次为5.5%,10.4%和8.8%;批间测定的精密度依次为7.4%,20.7%和19.1%。回收率为80.0%~111.5%,相对标准偏差为1.2%~15.4%。该方法前处理步骤简单,处理后杂质干扰少,灵敏度高,适用性强,可用于猪肉及禽类、水产品等多种动物组织中氯霉素类药物残留的检测。 相似文献