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71.
72.
Development of a Simple and Fast Electrochemical Method for Screening and Stoichiometric Determination of Dimenhydrinate
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Jhonys Machado Freitas Thiago da Costa Oliveira Polyana Luiza Silva Denise Tofanello Gimenes Rodrigo Alejandro Abarza Munoz Eduardo Mathias Richter 《Electroanalysis》2014,26(9):1905-1911
Dimenhydrinate (DIM) is a salt composed by the combination of two active pharmaceutical ingredients: diphenhydramine (DIP) and 8‐chlorotheophylline (CTP). In this work, the use of batch injection analysis with multiple pulse amperometric detection (BIA‐MPA) was proposed for the first time for fast stoichiometric determination of DIM. DIP (cation) and CTP (anion) were determined simultaneously in pharmaceutical samples with a simple and fast injection procedure (70 injections h?1). Additional strategies were also proposed for rapid screening of samples containing the DIM salt. By a simple injection of a sample into the BIA system (without using of calibration curve), reliable information about stoichiometry of the DIM salt (1 : 1; DIP:CTP) and presence or absence of interfering species (electroactive) can be achieved. 相似文献
73.
Peptide prefractionation is essential for proteomic approaches employing multiple‐reaction monitoring of fruit proteomic research
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Jun Song Leslie Campbell Palmer XiHong Li ZhaoQi Zhang 《Journal of separation science》2014,37(1-2):77-84
Off‐gel? IEF has become a popular tool in proteomics research to fractionate peptides or proteins. We conducted a detailed investigation on the fruit proteomics of apple, banana, and strawberry fruit employing Off‐gel? electrophoresis (OGE) as a crucial step to improve the proteome coverage and quantitative proteomic workflows including multiple‐reaction monitoring (MRM). We provide technical details concerning the application of Off‐gel?IEF, nano‐LC–MS detection, and MRM optimization and analysis. Our results demonstrated that the application of OGE is an effective method for peptide fractionation and increased significantly the number of proteins identified by at least ten times, with more total peptides detected and collected. Furthermore, we developed a protocol combining OGE and MRM studies to identify and quantitatively investigate monodehydroascorbate reductase, a key enzyme in the redox and antioxidant system of apple fruit during fruit ripening. Using this method, the quantitative changes in this protein during ripening and in response to ethylene treatment was investigated. Our results provide direct and comprehensive evidence demonstrating the benefits of OGE and its application for both shotgun and quantitative proteomics research. 相似文献
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Perchlorate ion (ClO4−) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined—the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 μg l−1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples. 相似文献
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微波消解ICP-AES法测定玩具塑料中镉 总被引:9,自引:0,他引:9
采用微波加压消解溶样,ICP-AES法测定玩具塑料中镉含量,选择最佳工作条件,方法简便、快速、可靠。适用于各类玩具塑料中镉含量的分析。 相似文献
80.
Tanikkul S Jakmunee J Lapanantnoppakhun S Rayanakorn M Sooksamiti P Synovec RE Christian GD Grudpan K 《Talanta》2004,64(5):1241-1246
A flow injection (FI) in-valve-mini-column packed with Chelex-100 resin is proposed for on-line sample pretreatment for some metal ions, namely, Cd(II), Pb(II) and Zn(II), prior to simultaneous determination using ion chromatography (IC). A solution containing a mixture of the cations was first passed through the in-valve-mini-column, followed by on-line elution. The eluate was then flowed further to an injection valve and was injected into an ion chromatograph. Conditions of the system were optimized. A single standard calibration was possible. The recoveries of cations were found to be in the range of 95–105%. The developed method was applied to the accurate analysis of zinc ore samples. 相似文献