Trace Determination of Benzalkonium Chlorides in River and Wastewater by Capillary Electrophoresis following Solid‐Phase Extraction Coupled with Salting‐Out Extraction

Trace levels analysisbenzalkonium chlorides (BAKs) in river water and wastewater treatment plants (WWTP) effluents were determined by capillary electrophoresis (CE) following solid‐phase extraction (SPE) and salting‐out extraction. Salting‐out extraction using an appropriate ratio of sodium chloride (NaCl) and acetonitrile (ACN) mixed with concentrated SPE elutant was capable of providing more than 500‐fold enhancement in detection sensitivity. The ratios of ACN and NaCl for salting‐out extraction were investigated and optimized. Matrix interference was eliminated by salting‐out extraction. Limits of quantitation of BAK homologues were achieved at 0.1 μg/L in 250 mL water samples. Recoveries of BAKs in various spiked water samples ranged from 70% to 84% with relative standard deviation (RSD) less than 9%. Trace amounts of total BAKs were detected in river water and WWTP effluent samples ranging from 27 to 145 μg/L at the first time by CE.     

Analytical methods for the characterization and the leachability evaluation of a solid waste generated in a phosphoric acid production plant

Naturally Occurring Radioactive Materials (NORM) are present in the environment and can be concentrated by technical activities, particularly those involving natural resources. These NORM deposits are highly stable and very insoluble under environmental conditions at the earth's surface. However reducing or oxidant conditions or pH changes may enable a fraction of naturally occurring radionuclides to eventually be released to the environment. In this paper the analytical methods to determine the chemical and radiochemical composition of a solid waste generated in an acid phosphoric production plant was shown. The sample, analysed by gamma spectrometry and radiochemical methods, contained ²¹⁰Pb and ²¹⁰Po and a high activity concentration of uranium isotopes but it shows a very low quantity of ²²⁶Ra. Also a sequential extraction method consisting of five operationally-defined fractions was used to evaluate the leachability of uranium isotopes, ²¹⁰Pb and ²¹⁰Po. The average leaching potential observed in the sample is 97.6% for ²³⁸U, 93.2% for ²¹⁰Pb and 82.4% for ²¹⁰Po. Moreover the results show that ²¹⁰Pb and ²¹⁰Po are leachable under only extreme conditions, whereas uranium is very more soluble.     

Solvent extraction and self-assembly of nanosized aggregates of p-tert-butyl thiacalix[4]arenes tetrasubstituted at the lower rim by tertiary amide groups and monocharged metal cations in the organic phase

New p-tert-butyl thiacalix[4]arenes functionalized with morpholide and pyrrolidide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations were synthesized, and their receptor properties for monocharged cations (alkali metal and silver ions) were studied using the picrate extraction method and dynamic light scattering (DLS). To evaluate the ability of the p-tert-butyl thiacalix[4]arene derivatives to recognize metal ions, liquid-liquid extraction of their picrate salts has been carried out in a mutually saturated water-dichloromethane system. The degrees of extraction and the extraction constants for monocharged metal cations (Li⁺, Na⁺, K⁺, Cs⁺) have been determined. The ability of the systems, consisting of host and guest molecules, to self-assembly was proved by DLS using a Zetasizer Nano ZS particle size analyzer. It was shown that all the investigated thiacalix[4]arenes are able to form nanoscale particles with silver cations under the experimental conditions. The pyrrolidide derivative in the cone conformation showed both self-association and aggregation processes with lithium cations. The degree of extraction for all the investigated systems that formed nanoscale aggregates in the organic phase was more than 67% and the extraction constants, log K_ex determined by the picrate extraction method, more than 6.     

基于微量热法的板蓝根提取方法和活性部位挑选

应用TAM Air微量热系统, 采用微量热法, 考察不同提取方法的板蓝根水煎液及其化学萃取部位在37 ℃时, 对大肠杆菌生长代谢的影响. 结合中医药理论, 分析板蓝根水煎液及其化学萃取部分的药效作用及其差异, 挑选板蓝根药材最佳的提取方法和抑菌最强的活性部位, 并采用试管稀释法求出抑菌活性最强部位的最小抑菌浓度(MIC). 结果表明微量热法可用于常用中药——板蓝根的提取方法和活性部位的挑选, 为进一步研究中药的药性基础提供了一种新的、快速灵敏的技术和方法.     

Solid phase extraction of copper (II) by sorption on octadecyl silica membrane disk modified with a new Schiff base and determination with atomic absorption spectrometry

A simple, selective and reliable method for rapid extraction and determination of trace amounts of Cu (II) ions from aqueous samples using octadecyl-bonded silica membrane disks modified with bis-(3-methoxy salicylaldehyde)-1,6-diaminohexane and flame atomic absorption spectrometry (FAAS) is presented. Extraction efficiency, the influence of pH, flow rates, amount of ligand, and type and least amount of eluant were investigated. The linear dynamic range of the proposed method for Cu (II) ions was found in a wide concentration range of 1.0 (± 0.2)–150 (± 2) μg l^− 1. The detection limit and preconcentration factor of this method were found 30.0 (± 0.7) ng l^− 1 and 100 respectively. The reproducibility of the procedure is at the most 2.0%. The effects of various cationic interferences on the percent recovery of copper ion were studied. The method was used to the recovery of copper ion from different synthetic, alloys and biological samples.     

溶胶-凝胶-硫化法制备硅橡胶吸附萃取搅拌棒

采用溶胶-凝胶-硫化法,以甲基乙烯基硅橡胶和乙烯基封端硅橡胶为原料制备了厚壁硅橡胶吸附萃取搅拌棒(stir bar for sorptive extraction,SBSE)。采用分段硫化和多阶程序升温老化防止涂层脱落和龟裂,一次涂渍涂层厚度约150~250μm,280℃下无流失,使用寿命可达150次。利用所制备涂层,结合自制热解析系统(thermal desorption system,TDS),建立了SBSE-TDS-CGC-FID测定水样中6种多环芳烃(polyaromatichydrocarbons,PAHs)的方法。方法的线性范围为0.3~1000μg/L,检出限为0.002~0.011μg/L,相对标准偏差在0.92%~6.14%之间。该方法能够满足欧盟2005/69/EC指令对多环芳烃低于10 mg/kg的检测要求。     

固相萃取气相色谱法测定水果中克菌丹和灭菌丹

采用硅镁吸附剂和硅胶作为混合固相萃取的净化方法,建立了固相萃取气相色谱法同时测定水果中克菌丹和灭菌丹的分析方法。研究了多种固相萃取柱和不同洗脱溶剂对克菌丹和灭菌丹保留行为的影响,优化了固相萃取净化方法及样品提取方法的分析条件。用GC-ECD检测,两种农药在0.05～2.0mg/L浓度范围内呈线性关系,相关系数大于0.997。苹果中4个浓度克菌丹和灭菌丹的加标回收率分别在100%～111%和104%～113%之间,RSD在3.0%～7.2%和2.8%～4.2%之间。在菠萝、草莓、梨和橙子中,克菌丹的平均回收率和RSD分别在95.6%～112%和2.5%～7.5%之间;灭菌丹在82.5%～96.4%和3.3%～8.0%之间,克菌丹和灭菌丹的方法检出限分别为0.012mg/kg和0.0056mg/kg。     

浊点萃取-高效液相色谱法同时测定人尿中的4种抗凝血鼠药

建立了基于浊点萃取同时测定人尿中杀鼠灵、杀鼠醚、溴敌隆和溴鼠灵的反相高效液相色谱法。以非离子表面活性剂TritonX-114为萃取剂,考察了色谱测定条件,优化了浊点萃取参数。5mL尿样中加入0.030gNaCl,30μL甲酸和5%(w/v)TritonX-114400μL,50℃萃取15min,4种目标物的萃取效率能达到85%以上。在选择的色谱条件下,以V(甲醇)∶V(1%甲酸)=90∶10为流动相,待测组分经反相C18色谱柱分离,于306nm波长处用二极管阵列检测器检测,10min可完成分析。4种鼠药中杀鼠醚在0.01～5.0mg/L,其余3种在0.02～5.0mg/L范围内呈良好的线性关系(r≥0.997);尿样的标准加入回收率为71.2%～114.5%;相对标准偏差小于7.0%。对于5mL尿液,富集相用50μL甲醇稀释,萃取浓缩因子可达到28倍。定量检出浓度分别为:杀鼠灵0.016mg/L,杀鼠醚0.001mg/L,溴敌隆0.005mg/L,溴鼠灵0.003mg/L。本法简便快速、灵敏可靠、绿色环保,能满足鼠药中毒应急检测的要求。     

碱液萃取前后原油中酸性化合物组成的高分辨质谱分析

采用改进的碱液萃取方法分离杜巴原油中的酸性化合物(主要是环烷酸),通过高分辨质谱分析萃取过程中不同组分酸性化合物组成,以研究碱萃取前后酸性化合物的分布与组成特征。实验结果表明,电喷雾傅立叶变换离子回旋共振高分辨质谱(ESI-FT-ICR-MS)是分析原油中酸性化合物的强有力的手段;酸性化合物分布于碱萃取前后的各个组分中,但其组成有明显的差异,碱液萃取出的石油酸主要是相对分子质量小于500的酸性组分,增加反萃取溶剂的用量和极性有利于脱除萃取物中的非碱性氮化合物,对石油羧酸的组成影响不大。     

微流控芯片分析系统中硅胶整体柱和膜滤复合预处理单元的构建

以改性C18反相硅胶整体柱为微流控芯片分析系统中固相萃取介质材料, 构建不同功能单元的样品预处理微分析系统, 实现了血清样品中痕量盐酸多巴酚丁胺的富集. 初步构建了单一改性硅胶微柱固相萃取预处理单元, 测试得到了改性硅胶整体柱对血清中痕量盐酸多巴酚丁胺的平均富集倍数为77.2, RSD为12.35％. 为了提高测试的精密度, 进而设计含膜复合式预处理芯片, 探讨了不同预处理单元对血清样品中痕量盐酸多巴酚丁胺富集效率的影响, 优化设计了外接式硅胶整体柱-亲和膜微芯片固相萃取预处理单元, 复合式的反相硅胶整体柱对血清中微量盐酸多巴酚丁胺的平均富集倍数提高到89.4, RSD为4.37％. 结果显示了该预处理单元在血清中痕量药物富集的可行性和有效性.