固相萃取-高效液相色谱法测定鸡肝中磺胺类药物残留量

建立了一种鸡肝中7种磺胺类药物残留量固相萃取-反相高效液相色谱分析方法。对样品提取后磺胺类药物在氨基键合固相萃取柱上的保留行为进行了研究。采用Intersil ODS-3 C18柱,以甲醇-乙腈冰．乙酸为流动相梯度洗脱,进行高效液相色谱分离,二极管阵列检测器检测,外标法定量。7种磺胺类药物标准曲线的线性回归系数均在0．999以上,线性范围为25—10000μg／L;检出限在8—12μ／kg之间;在50、100、200μg／kg^3个添加浓度水平下添加回收率在69．6％-91．3％范围内;相对标准偏差在4．3％-8．0％之间。该方法具有快速、灵敏、环保的特点,符合现行兽药残留分析的要求。     

固相萃取分离-高效液相色谱法测定陈皮中噻菌灵残留量

试样于磷酸(1+999)溶液中浸泡2 h,超声振荡20 min,加水定容为50 mL离心3 min,分取上层澄清液5.0 mL,通过ENVITMC18固相萃取柱纯化.用由0.1 mol·L-1磷酸二氢钾溶液(pH 3.0)与乙腈以70比30的体积比组成的混合液(此溶液也用作流动相)作为淋洗液,将被测定物质从固相萃取柱上洗脱,所得淋出液供高效液相色谱(HPLC)测定.HPLC分析中,LC-SCX离子交换柱用作色谱柱,上述的混合溶液作为流动相,荧光检测的激发波长为307 nm,发射波长为359 nm.噻茵灵的质量浓度在0.5～100.0μg·L-1范围内与其相应的峰面积值之间呈线性关系,在3个浓度水平上对回收率作了试验,测得回收率在88.0%～95.0%之间,相对标准偏差(n=6)在3.1%～5.0%之间.     

固相萃取-高效液相色谱法测定果蔬中异菌脲残留量

建立了固相萃取-高效液相色谱法测定果蔬中异菌脲残留量的方法。样品用乙腈提取,C18固相萃取柱净化,甲醇-水(70:30,V/V)为流动相,经C18液相色谱柱分离,DAD紫外检测器(218 nm)检测。结果表明:异菌脲在0.1~2.0 mg/L范围内线性关系良好(R2=0.9998),方法定量限(以S/N=10计)为0.05 mg/kg,在0.05,0.1,0.5 mg/kg添加水平下的加标回收率范围为81.3%~98.3%,相对标准偏差(n=6)为3.9%~8.9%。方法适用于大多数水果、蔬菜中异菌脲残留量的测定。     

固相萃取高效液相色谱法测定动物肝中四种磺胺残留量

用高效液相色谱法同时测定了动脉肝中四种磺胺药物残留量。样品经乙腈－氯仿提取，液－液萃取、固相萃取小柱净化后用HPLC分离，外标法定量。方法简便、快速，下限为0.050mg/kg，回收率＞82％，相对标准偏差＜5％。     

固相萃取-高效液相色谱法测定汤料中罂粟壳提取物残留量

提出了高效液相色谱法测定汤料中罂粟壳提取物吗啡、可待因和罂粟碱残留量的方法。样品用乙醚萃取,经离心分离,取上清液通过固相萃取柱纯化。流出液经过滤后,取10μL进样,在Zorbax SB C18色谱柱上进行分离,以不同比例混合的乙酸铵溶液和甲醇作为流动相进行梯度淋洗。吗啡、可待因和罂粟碱的线性范围均为0.05～50mg....     

分散固相萃取-高效液相色谱法快速测定果蔬中的6种保鲜剂残留量

建立了采用分散固相萃取-高效液相色谱同时测定果蔬中2,4-滴、噻苯咪唑、乙萘酚、邻苯基苯酚、二苯醚和联苯6种保鲜剂残留量的方法。样品经乙腈提取(同时加入氯化钠和无水硫酸镁),提取液经酸性氧化铝分散固相萃取净化,采用Agilent TC C18色谱柱(250 mm×4.6 mm, 5 μm),以甲醇-0.02 mol/L的磷酸二氢钾溶液(pH 6)作为流动相,流速1.0 mL/min,梯度洗脱,用紫外检测器检测,检测波长为235 nm,外标法峰面积定量。6种保鲜剂在0.5～20 mg/L范围内线性关系良好,相关系数均大于0.99; 6种保鲜剂在样品中添加1、2和10 mg/kg 3个浓度水平的回收率为84.2%～99.1% (n=6),相对标准偏差为1.67%～10.3%;方法的定量限为1 mg/kg。该法简便、准确,适用于果蔬中6种保鲜剂残留量的检测。     

固相微萃取高效液相色谱法测定食品中己烯雌酚

建立了固相微萃取(SPME)-高效液相色谱(HPLC)联用测定食品中己烯雌酚(DES)的方法.考察了萃取纤维头、萃取时间、解吸时间和盐的添加对萃取效果的影响.在此基础上,采用正交试验,以解析液组成、萃取液pH和搅拌速度为3因素筛选出了最佳固相微萃取条件.该分析方法的线性范围为0.02 ～2.0μg/ml,工作曲线线性良...     

固相萃取高效液相色谱法测定茶叶中多酚

研究了用固相萃取预分离,高效液相色谱法测定茶叶中多酚的方法。茶多酚提取液用Sep-Park-C18固相微萃取小柱预分离纯化,以Nova-Pak-C18色谱柱为固定相,0.05 mol.L-1磷酸二氢钾缓冲溶液和甲醇梯度洗脱为流动相,在该条件下茶叶中主要的植物多酚均达到基线分离;用紫外二极管矩阵检测器检测,各组分均用最大波长色谱图的峰面积定量,并用二极管矩阵检测器记录的紫外光谱图对主要多酚进行辅助定性。方法标准回收率为94%~106%,相对标准偏差为1.22%~1.57%。方法应用于茶叶样品中多酚的测定,结果满意。     

固相萃取-高效液相色谱法测定茶叶中有机氮农药残留量

提出了茶叶中5种有机氮农药(速灭威、残杀威、呋喃丹、甲萘威、抗蚜威)残留的高效液相色谱法.样品用丙酮-正己烷(1 2)混合溶剂提取,经石墨碳固相小柱净化,以VP-ODS C18柱分析,乙腈-60 mmol·L-1磷酸(40 60)溶液为流动相,流速为1.0 mL·min-1,检测波长210 nm,外标法定量.在0.10～2.0 mg·kg-1之间的添加水平,5种有机氮农药的平均回收率在80.1%～94.8%之间,相对标准偏差在2.21%～7.13%之问,检出限在0.0125～0.05 mg·kg-1之间.     

固相萃取-高效液相色谱法测定水产品中喹乙醇

建立了固相萃取-高效液相色谱法测定水产品中喹乙醇的方法。匀浆后的水产品试样经甲醇溶液提取、正己烷除脂、固相萃取小柱直接净化浓缩后,以体积分数15%的甲醇溶液作为流动相,流速:1.0 m L/min,采用Symmetryshield TM RP18色谱柱进行分离,紫外检测器检测,外标法定量。方法的检出限和定量限分别为0.02 mg/kg和0.05 mg/kg,浓度在0.05~1.00 mg/L范围内,线性良好(r=0.9999)。添加浓度在0.05~1.00 mg/kg时,不同品种水产品的回收率在78%~99.6%之间,相对标准偏差小于7.7%。方法适合于水产品样品的成批定量检测。     

SPE-HPLC-MS定量法测定果蔬中农药马拉硫磷残留量

建立了SPE-HPLC-MS法定量测定果蔬中农药马拉硫磷残留量。固相萃取小柱为SupelcleanTM ENVITM-18柱（3 mL）,丙酮为洗脱液;色谱柱为安捷伦快速高分离亚二微米液相色谱柱Zorbax RRHTSB-C18（1.8μm,4.6 mmi.d.×50mm,Agilent）;流动相为70%甲醇（含2 mmoL甲酸铵）＋30%水,等梯度洗脱;质谱采用正离子电离方式,选择m/z 283和m/z 243碎片离子为定性离子,以丰度最高的碎片离子m/z 283为定量离子,用MRM模式监测;外标法定量。方法相关系数r2=0.9968,检出限（LOD）为0.002 mg/kg,加标回收率为78.3%-96.2%,相对标准偏差（RSD）为3.5%-18.8%,适合样品中低含量马拉硫磷残留量的测定。     

固相萃取高效液相色谱法测定乳粉中苯并咪唑类药物残留

研究了乳粉中丙硫咪唑、噻苯咪唑、苯硫咪唑、噻苯咪唑酯、苯亚砜苯咪唑等五种苯并咪唑类药物液相色谱测定方法。乳粉中苯并咪唑类药物残留经碱性乙酸乙酯提取,Waters Oasis HLB固相萃取柱净化,以Cloversil C18柱为固定相,甲醇和0．02mol／LKH2P04为流动相,紫外检测器下测定。该法检出限为0．020mg／kg,添加标准0．10mg／kg的回收率为71％-90％。     

Indirect Determination of the Pesticide Malathion by Atomic Absorption Spectrophotometry

Abstract

A method for the indirect determination of the pesticide malathion by atomic absorption spectrophotometry (AAS) is proposed and compared with the standard spectrophotometric method.

A study of the influence of the different variables on the hydrolysis and extraction is carried out in order to obtain the best experimental conditions.

The proposed method offers clear advantages over the standard procedure because of the instability of the Cu (II) complex formed. Both methods are applied to the determination of malathion in two commercial formulations.     

固相萃取高效液相色谱法测定姜黄中的苏丹色素

研究了姜黄中4种苏丹色素的液相色谱测定方法。姜黄中4种苏丹色素经正己烷提取,Supelco中性氧化铝小柱净化,色谱柱为ZORBAX Eclipse XDBC18,以乙腈-水为流动相,采用梯度洗脱,二极管阵列检测器测定。该法检出限分别为0．040,0．058,0．038,0．060mg／kg,回收率在84．5％～94．3％之间,相对标准偏差（RSD）≤4．5％。     

固相萃取-高效液相色谱法测定动物尿样中的莱克多巴胺

莱克多巴胺（ractopamine）是一种新型的β-肾上腺素兴奋剂,我国农业部、卫生部、国家药品监督管理局在2002年联合下发的176号公告中已经明确将其列入禁用药品名单。目前,文献报道的莱克多巴胺的检测方法很少,特别是国内还未见文献报道。由于莱克多巴胺在动物体内代谢较快,因而药物往往以原形的形式从体内排出。检测动物尿样具有快速、准确等特点,建立动物尿样中的莱克多巴胺的检测方法可以对畜产品生产过程中使用莱克多巴胺的现象进行有效的监控。因此,探索动物尿样中莱克多巴胺的检测方法具有非常重要的理论意义和实际价值。本文建立了动物尿样中莱克多巴胺残留量的高效液相色谱（HPLC）测定方法,样品处理简单,灵敏度高。     

Electrochemical Determination of Malathion on an Acetylcholinesterase-Modified Glassy Carbon Electrode

An acetylcholinesterase biosensor based on glassy carbon electrode modified with carbon black and pillar[5]arene was used for the determination of malathion after its preliminary oxidation. The contributions of enzyme immobilization and oxidation conditions to the improvement of analytical characteristics of the biosensor were considered and quantified. In optimal conditions, the acetylcholinesterase biosensor allows the determination of 40 pM of malathion with 10?min of incubation and 15 pM with 30?min of incubation. The sensitivity of immobilized enzyme was found to be higher than that the free enzyme due to sorbtional accumulation in the modifier layer. Incomplete oxidation of malathion decreased the sensitivity of the assay. The developed acetylcholinesterase biosensor was validated for the determination of malathion residues in grapes, wine, and peanuts. The recoveries calculated against a high-performance liquid chromatography assay were between 80 and 120% due to possible matrix effects and the simplified extraction protocols.     

气相色谱-氮磷检测器法表征家蝇对马拉硫磷的水解代谢

为明确家蝇对马拉硫磷的水解代谢能力及相关代谢抗性，在用常规模式底物α-萘乙酯表征了敏感及抗性家蝇的水解酶活性的基础上，使用气相色谱-氮磷检测器（GC-NPD）法比较了抗性及敏感家蝇水解酶对马拉硫磷的水解代谢能力的差异。结果表明，用2：1（v/v）的乙酸乙酯与正己烷混合物萃取后，GC-NPD可成功测定家蝇酶制备液与马拉硫磷温育后的马拉硫磷含量变化，从而可以表征家蝇酶制备液对马拉硫磷的代谢能力。马拉硫磷抗性家蝇水解酶代谢α-萘乙酯的能力是敏感家蝇的1.39倍，代谢马拉硫磷的能力是敏感家蝇的6.68倍，表明家蝇对马拉硫磷的抗性与其对马拉硫磷代谢能力增强有关。该法可用于家蝇等昆虫对马拉硫磷的代谢能力及相关抗性机制研究。     

Determination of ng rivanol in human plasma by SPE-HPLC method

A high-performance liquid chromatography assay is described for the determination of rivanol in human plasma. Solid-phase extraction cartridges are used to extract plasma samples. Separation is done by using a C18 column. The mobile phase is a mixture of methanol-0.05% sodium dodecylsulfonate (70:30, v/v, pH 3), with the flow rate at 1.0 mL/min. UV detection of rivanol is at 272 nm. The calibration curve is linear in the concentration range of 1x10(-8) mol/L to 1x10(-5) mol/L with linear correlation coefficient r equal to 0.9998. The limit of detection for the assay is 3x10(-9) mol/L, corresponding to 1.1 ng/mL. Precision, expressed as the within- and between-day coefficient of variation, is 3.3-8.1% and 4.1-9.5%, respectively, at plasma control samples of 5x10(-8), 5x10(-7), and 5x10(-6) mol/L. And the recovery ranges from 94.8% to 107.2%. The selectivity of the method is confirmed. Plasma samples are stable for at least 15 days if they are stored lightproof at -20 degrees C. This method is simple, sensitive, and accurate, and it allows for the determination ng rivanol in human plasma. It could be applied to assessing its plasma level in women receiving an intra-amniotic injection of rivanol.     

Metal organic frameworks enhanced dispersive solid phase microextraction of malathion before detection by UHPLC‐MS/MS

Metal organic frameworks are considered as an efficient and promised adsorbent for separation of several ions and compounds from solutions due to its unique geometric structure. Herein, copper‐benzyl tricarboxylic acid based metal organic frameworks have showed a high efficiency in enrichment and microextraction of malathion from food and water samples. The microextraction procedures were followed by determination of malathion by ultra high performance liquid chromatography with tandem mass spectrometry. The optimum recoveries for malathion were obtained at pH 6, and with using 2 mL of ethyl acetate as the eluent. The microextraction procedures showed a detection limits and the quantification limits of 4.0 and 10.0 µg/L, respectively. The intra‐ and interday precision showed a relative standard deviation% less than 10. The feasibility of the proposed procedure was determined by evaluating the addition/recovery studies of malathion from the real samples. The absolute recovery% was ≥92%. Furthermore, some ions were tested as cointerfering ions, and the recovery% was 93‐100%. These results confirm that the developed microextraction procedure based on copper‐benzyl tricarboxylic acid based metal organic frameworks as extractor for dispersive solid phase microextraction is matrix‐independent, and can be applied for various real samples including different matrix or various malathion content.