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991.
Elnaz Marzi Khosrowshahi Behnaz Limuie Khosrowshahi Mir Ali Farajzadeh Abolghasem Jouyban Mustafa Tuzen Mohammad Reza Afshar Mogaddam Mahboob Nemati 《Biomedical chromatography : BMC》2022,36(7):e5371
A dispersive solid-phase extraction method based on a new sorbent has been performed on plasma and wastewater samples to determine metoprolol by high-performance liquid chromatography–tandem mass spectrometry. In this study, the analyte was adsorbed from the samples onto microcrystalline cellulose as a green and efficient sorbent and then eluted for use in the determination step. In the mass spectrometer, the analyte was detected in the positive mode and selectivity of the analysis was increased by sequential mass analysis through multiple reaction monitoring. All of the effective parameters in the extraction of metoprolol from plasma and wastewater were optimized. Under optimal conditions the method was linear in the ranges of 1–1,000 and 0.1–1,000 ng/ml in plasma and wastewater samples, respectively. The detection limits of the method were 0.30 and 0.03 ng/ml in plasma and wastewater samples, respectively. The data showed that the method provides low detection limit, wide linear range, good precision and high extraction recovery. Finally several plasma and wastewater samples were successfully analyzed using the method. The use of a small amount of a green and inexpensive sorbent and a low volume of plasma without the need for further pretreatment steps are the main advantages of the method. 相似文献
992.
Jianfeng Zhang Dr. Marco Wenzel Johannes Steup Gerrit Schaper Dr. Felix Hennersdorf Prof. Dr. Hao Du Prof. Dr. Shili Zheng Prof. Dr. Leonard F. Lindoy Prof. Dr. Jan J. Weigand 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(1):e202103640
Effective receptors for the separation of Li+ from a mixture with other alkali metal ions under mild conditions remains an important challenge that could benefit from new approaches. In this study, it is demonstrated that the 4-phosphoryl pyrazolones, H L 2-H L 4, in the presence of the typical industrial organophosphorus co-ligands tributylphosphine oxide (TBPO), tributylphosphate (TBP) and trioctylphosphine oxide (TOPO), are able to selectively recognise and extract lithium ions from aqueous solution. Structural investigations in solution as well as in the solid state reveal the existence of a series of multinuclear Li+ complexes that include dimers (TBPO, TBP) as well as rarely observed trimers (TOPO) and represent the first clear evidence for the synergistic role of the co-ligands in the extraction process. Our findings are supported by detailed NMR, MS and extraction studies. Liquid-liquid extraction in the presence of TOPO revealed an unprecedented high Li+ extraction efficiency (78 %) for H L 4 compared to the use of the industrially employed acylpyrazolone H L 1 (15 %) and benzoyl-1,1,1-trifluoroacetone (52 %) extractants. In addition, a high selectivity for Li+ over Na+, K+ and Cs+ under mild conditions (pH ∼8.2) confirms that H L 2-H L 4 represent a new class of ligands that are very effective extractants for use in lithium separation. 相似文献
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建立灵敏、可靠的中药材中农药多残留的检测方法对保证中药材的质量和安全十分重要.制备了磁性亲水亲脂平衡萃取材料Fe3 O4@PLS,将其应用于农药多残留的磁性基质固相分散萃取中,并结合高效液相色谱-串联质谱法(HPLC-MS/MS)检测了金银花、菊花和三七块根(干)3种中药材中76种农药残留量.研究通过扫描电子显微镜(S... 相似文献
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我国水产品中多氯联苯(PCBs)的检测方法,主要以6种指示性PCBs和12种二噁英类共平面PCBs为主,仅涵盖有限的PCBs。为更全面地获得生物体中PCBs的浓度水平,深入探讨PCBs在生物体内的代谢和富集特征,进而准确评价PCBs对人类的暴露水平及风险,以鱼和贝类作为生物样品代表,建立了加速溶剂提取-同位素稀释-高分辨气相色谱-高分辨质谱(ASE-ID-HRGC-HRMS)测定生物样品中82种PCBs的方法。比较了振荡提取和加速溶剂提取两种提取方式的回收率和重复性,最终采用正己烷-二氯甲烷(1∶1, v/v)对PCBs进行加速溶剂提取。考察了各流分淋洗液对PCBs的回收率,确定了样品提取液经8 g 44%酸性硅胶层析柱(内径15 mm), 90 mL正己烷洗脱的净化方式。样品提取液净化浓缩后进行HRGC-HRMS分析,色谱柱采用DB-5MS超低流失石英毛细管柱(60 m×0.25 mm×0.25 μm)。通过优化后的升温程序对化合物进行分离,以保留时间和两个特征离子精准定性,采用同位素内标法定量。结果表明,在0.1~200 μg/L范围内,平均相对响应因子(RRF)的相对标准偏差值(RSD, n=7)均≤20%,相关系数(r2)>0.99。生物样品中PCBs的方法检出限为0.02~3 pg/g;鱼类中PCBs平均加标回收率为71.3%~141%, RSD(n=7)为2.1%~14%;贝类中PCBs平均加标回收率为76.9%~143%, RSD为1.4%~11%。该方法灵敏、准确、可靠,可以更加全面具体地分析鱼和贝类等水产品受PCBs的污染情况,为国内外开展生物监测提供有效的技术支持,从而服务于相关生态环境管理及履行《斯德哥尔摩公约》。 相似文献
998.
The surface analysis of wood and wood products is becoming increasingly important for reasons ranging from the investigation of molecular constituents through to the optimization of industrial processes. As with any natural product, wood analysis is not straightforward, and this review aims to provide guidance for the successful surface analysis of wood by XPS and ToF-SIMS. Through example experiments, three themes are addressed relevant to obtaining meaningful results: considerations related to heterogeneity in the composition of wood (e.g., growth rings); the impact of the chemical removal of minor wood components known as extractives, and whether such a process is necessary; and the potential for misleading or erroneous results as a result of contamination occurring during sample preparation. In addition to discussing successful sample preparation approaches, the important role to be played by MVA in surface analysis is emphasized, particularly in the analysis of ToF-SIMS data. Examples of ToF-SIMS/MVA are provided that highlight the identification of contamination in sample preparation, the quantification of wood composition in terms of cellulose and lignin, and the indication of age of softwood samples. Through consideration of the complexities that influence wood surface analysis, the design and interpretation of consequential experiments become easier and more accurate. 相似文献
999.
An analytical method for the simultaneous determination of 12 additives in beverages was developed using evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets EVA-DLLME-SFOcombined with high performance liquid chromatography HPLC. The samples were extracted twice with 70%V/Vmethanol aqueous solution and extracted by EVA-DLLME-SFO method after the combination of the extractsand finally determined by HPLC. Extraction parameterssuch as types and amounts of extractantevaporant and heating agentthe concentration of saltand the extraction time were optimized. Under the optimized conditionsthere were good relationships in the ange of 0.25-50 μµg/mL with the limits of detection of 1.5 to 13.6 mg/kg and limits of quantification of 5.2 to 45.3 mg/kg. The recoveries at three spiked levels1025 and 50 mg/kgwere 76.8% to 101.2% with the relative standard deviations of 0.11% to 4.7%. The method can be used for rapid detection of 12 additives in beverages. © 2022, Youke Publishing Co.,Ltd. All rights reserved. 相似文献
1000.
葛丹丹王颖臻张毅宋家漫沈茂珍 《分析试验室》2022,(7):815-820
建立了一种基于低共熔溶剂的旋涡辅助分散液-液微萃取和高效液相色谱连用检测水样中臧红T和胭脂红染料的方法。制备了一类分别由苄基三乙基溴化铵、苄基三丁基溴化铵、苄基三乙基氯化铵或苄基三丁基氯化铵(氢键受体)和正辛酸(氢键供体)组成的新型疏水性低共熔溶剂。最佳萃取条件为:选取苄基三丁基氯化铵和正辛酸(摩尔比为1∶2)制备的低共熔溶剂为萃取剂,萃取剂用量为75μL,萃取时间为1 min,溶液pH=7,NaCl浓度为3 mg/mL。在最优化条件下,检测臧红T和胭脂红的线性范围为4.8~1000 ng/mL;相关系数(R^(2))分别为0.9981和0.9987;检出限分别为1.5和1.8 ng/mL;定量限均为4.8 ng/mL。将该方法应用于实际水样中臧红T和胭脂红的测定,加标回收率为88.5%~113.6%,相对标准偏差均低于8.8%。 相似文献