快速分离柱高效液相色谱法测定环境水样中多菌灵和噻菌灵的研究

研究并建立了用固相微萃取-快速分离柱高效液相色谱法测定环境水样中的多菌灵和噻菌灵的方法。样品中的多菌灵和噻菌灵用W aters Sep-pak C18反相固相萃取小柱预分离和富集,然后以ZORBAX Stab leBound(4.6 mm×50 mm,1.8μm)C18快速分离柱为固定相,甲醇-水(V(甲醇)/V(水)=1∶1)为流动相进行分离,流速为2.0 mL/m in;用二极管矩阵检测器检测,检测波长为286 nm,样品中的多菌灵和噻菌灵在2.0 m in内可达到基线分离。方法标准回收率为93%~104%,RSD为2.1%~3.2%。用新方法测定了环境水样中的多菌灵和噻菌灵,结果令人满意。     

纳米Ir／SPE电极的制备及其影响因素

首次选用镍作为中间催化剂,采用吸附还原成长法制备纳米Ir/SPE电极,并就镀浴温度和pH值、H2IrCl6浓度、NaBH4与H2IrCl6配比对电极制备的影响作了深入研究。研究表明:采用吸附还原成长法,以Ni作为中间催化剂,浓度为22mmol·L-1NaBH4与浓度为6mmol·L-1H2IrCl6的混合液作为镀浴,亦即NaBH4与H2IrCl6配比为3.6,pH值为8,镀浴温度为40℃,镀浴时间为24h的条件下,循环镀覆3次,可获得致密、均匀,具有良好电解性能的纳米级Ir/SPE电极。     

SPE 水电解槽阳极温度场数值模拟

基于计算流体动力学原理建立了蛇形流道固体聚合物电解质(SPE)水电解槽阳极的三维稳态气液混合两相流动数学模型,应用通用计算流体动力学(CFD)软件fluent进行了数值模拟,得到了电解槽阳极的温度分布特点,分析了不同流道宽度、肋宽和流道深度对电解槽阳极温度分布的影响,为电解槽阳极流场板的优化设计提供一定的参考。     

Simultaneous and confirmative detection of multi-residues of β2-agonists and β-blockers in urine using LC-MS/MS/MS coupled with β-receptor molecular imprinted polymer SPE clean-up

A liquid chromatography–linear ion-trap spectrometry (LC-MS³) method using β-receptor molecular-imprinted polymer (MIP) solid-phase extraction (SPE) as clean-up was developed to determine simultaneously and confirmatively residues of 25 β₂-agonists and 21 β-blockers in urine samples. Urine samples were subjected to enzymatic hydrolysis by β-glucoronidase/arylsulphatase, and then extracted with perchloric acid. Sample clean-up was performed using β-receptor MIP SPE. A Supelco Ascentis^® express Rp-Amide column was used to separate the analytes, and MS³ detection used an electrospray ionisation source in positive-ion mode. Recovery studies were carried out using blank urine samples fortified with the 46 analytes at the levels of 0.5, 1.0 and 2.0 μg l^–1. Recoveries were obtained ranging from 60.1% to 109.9% with relative standard deviations (RSDs, n = 7) from 0.5% to 19.4%. The limits of detection (LODs) and limits of quantitation (LOQs) of the 46 analytes in urine were 0.02–0.18 and 0.05–0.60 μg l^–1, respectively. As a result of the selective clean-up by MIP SPE and MS³ detection of the target drugs, the sensitivity and accuracy of the present method was high enough for monitoring β₂-agonist and β-blocker residues in urine samples. Satisfactory results were obtained in the process of the determination of positive urine samples.     

固相萃取和气相色谱法测定大米中氟虫腈(锐劲特)残留

建立运用固相萃取技术检测大米中的氟虫腈残留的气相色谱分析方法。样品经过乙腈/丙酮(70/30)抽提,通过硅酸镁(Florisil)固相萃取(SPE)小柱净化,旋转蒸干后用乙腈定容,应用微池电子捕获检测器(μ ECD)检测。样品在10 μ g/kg、15 μ g/kg和30 μ g/kg三个浓度水平添加,回收率为83.18%、 84.49%和88.85%,方法变异系数为1.60%、 1.89%和1.54%。本方法在大米样品中的最低检测定量限为10 μ g/kg     

水中致癌芳香胺的固相萃取-气质分析方法研究

采用固相萃取-气相色谱质谱法分析了水中24种致癌芳香胺的含量,结果表明,该方法的检出限低于0.36 μg/L。固相萃取的优化条件为：选用Envi-chromp固相萃取小柱,水样pH 8~10,二氯甲烷洗脱2次。绝大多数芳香胺的空白水样加标回收率在88.8%~111.8%之间,标准偏差为6.8%~9.9%。对浙江省13个饮用水源地的地表水进行检测,均未检出24种致癌芳香胺。降解实验表明,大多数芳香胺化合物在水中能稳定存在14 d以上。     

固相萃取技术及其在环境分析中的应用

固相萃取技术作为一种高效的样品制备技术 ,近年来得到越来越广泛的重视和应用。本文将对这一技术的原理、特点及其在环境样品处理方面的应用进行介绍     

凝胶色谱-固相萃取-气相色谱-串联质谱法测定水产品中9种三嗪类除草剂

建立了水产品中9种三嗪类除草剂的凝胶色谱 固相萃取-气相色谱-串联质谱(GPC-SPE-GC-MS/MS)分析方法。样品采用乙酸乙酯提取,凝胶渗透过滤,石墨化碳串联氨基柱净化,选择离子监测模式测定,外标法定量。结果表明：扑灭津、阿特拉津、特丁津、西玛津、扑草净在1.0~50.0 μg/L范围内线性良好,检出限均为1.0 μg/kg,在1.0~10.0 μg/kg添加水平,平均回收率为86.3%~119%,相对标准偏差为5.11%~10.1%;环草津、莠灭净、特丁净、西草净在2.0~100.0 μg/L范围内线性良好,检出限均为2.0 μg/kg,在2.0~20.0 μg/kg添加水平,平均回收率为87.6%~112%,相对标准偏差为5.27%~9.56%。该方法稳定、可靠,适用于水产品中9种三嗪类除草剂的同时测定。     

Composite anion exchange membrane for alkaline direct methanol fuel cell: Structural and electrochemical characterization

A copolymer of 4‐vinylpyridine (4‐VP) and styrene was synthesized by radical mass polymerization using 2,2′‐azobisisobutyronitrile as initiator. An insoluble (linear) pyridinium‐type polymer was prepared by the reaction of P (4VP–St) with 1‐bromooctane. An anion exchange membrane was prepared using a composite of pyridinium‐type polymer and a fibrous woven structure for use in electrochemistry. The composite membrane was characterized by X‐ray diffraction, tensile strength, scanning electron microscopy, and electrochemistry measurements. The experimental results showed that the fibrous woven product had improved the tensile strength more than had the membrane made of a pyridinium‐type polymer alone. The composite membrane was used in alkaline fuel cells, and its properties were measured by electrochemical analysis. The ionic conductivity of the membrane was acceptable, but its performance as a direct methanol fuel cell (DMFC) was not. The primary reason for this was analyzed, and research is ongoing, with analysis to be discussed in later reports. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2248–2251, 2006     

河流底泥沉积物中五氯酚和六氯苯残留的同时测定

建立了冷冻干燥，超声波提取，弗罗里硅土固相萃取净化(Florisil SPE cleanup)，气相色谱-质谱(GC/MS)检测河流底泥沉积物中五氯酚（PCP）和六氯苯（HCB）残留的方法。方法加标回收率在91%~ 99%之间，相对标准偏差小于10%。检测五氯酚和六氯苯的方法检出限（干重）分别为0.038 3 μg/g、0.053 2 μg/g。应用该方法进一步研究了取样点底泥沉积物剖面PCP、HCB含量与总有机碳(TOC)的分布特征。由此推测TOC可能是PCP和HCB在底泥沉积物剖面中沿纵深向下层迁移的一个重要载体。