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61.
An MEKC method for the analysis of goserelin and related substances has been developed using a combination of additives including CTAB, β‐CD, and sodium hexanesulfonate. For this assay, the running buffer (pH and additives) and separation conditions (voltage and temperature) were optimized. The optimized system was the following: 200 mM 6‐aminocaproic acid buffer (pH 4.2) supplemented with 175 mM CTAB, 3.0% w/v β‐CD, and 20 mM sodium hexanesulfonate; the voltage was 10 kV in reverse polarity mode, the temperature was 20°C, and UV detection was measured at 220 nm. The method was qualified by evaluating the specificity, precision, linearity, accuracy, LOD, and LOQ. According to validation experiments, the optimized method was specific, accurate, and repeatable and satisfied the requirements for the analysis of goserelin and related substances. Compared with the RP‐HPLC method, the MEKC method better solved the problem of overlapping impurity signals, and the migration time required was shorter. This method can be used for quality control and for the analysis of goserelin and its related substances. 相似文献
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Validated multi‐drug determination using liquid chromatography with tandem mass spectrometry for the evaluation of a commercial drug disposal product 下载免费PDF全文
Veronica B. Waybright Stephanie H. Ma Kevin A. Schug 《Journal of separation science》2016,39(9):1666-1674
Currently, there are limited effective means of drug disposal for consumers, and this creates a gateway to illicit use and environmental contamination. Here, we evaluated the efficacy of a new drug disposal product, composed from a slurry of activated carbon, which claims to sequester up to 100% of a drug's active ingredient when the loading capacity is not exceeded, making it safe to dispose in landfill. High‐performance liquid chromatography with tandem mass spectrometry was applied to quantify as many as 24 drugs (opiates, barbiturates, statins, amphetamine, and benzodiazepine drugs) in the residual solvent solution from the product. Calibration curves were established in the concentration ranges of 0.25–7.0 μg/mL and showed good linearity. The limits of detection varied from 0.001 to 0.02 μg/mL, depending on the drug. Accuracy ranged from 80 to 111% for quality control samples, with a few minor exceptions. Precision overall varied between 0.2 to 12.7%. In sample bottles tested, where active ingredient of the loaded drug was below the maximum sorption capacity stated on the label, 98 to >99.9% of the active ingredient was sequestered. Percent active ingredient adsorbed was slightly lower in bottles loaded in excess of label specifications. 相似文献
64.
Volatile flavoring substances in foodstuffs 总被引:1,自引:0,他引:1
H G Maier 《Angewandte Chemie (International ed. in English)》1970,9(12):917-926
The odor of most foods is produced by mixtures of many volatile flavoring substances. Over the past century, numerous food flavors have been analyzed in sufficient detail to allow a survey of the classes of substances responsible, the formation of individual flavoring substances, and their fixation in the foods. In addition to special biosynthetic pathways, the breakdown of fats and the Maillard reaction have been found to be particularly important to the formation of flavoring substances. 相似文献
65.
Roots of Arctium tomentosum (Compositae) were found to contain water-soluble polysaccharides (glucofructans), pectinic substances, and hemicellulose. The structure of the glucofructan was established by chemical methods and IR and 13C NMR spectroscopies. 相似文献
66.
Solving large scale linear systems efficiently plays an important role in a petroleum reservoir simulator, and the key part is how to choose an effective parallel preconditioner. Properly choosing a good preconditioner has been beyond the pure algebraic field. An integrated preconditioner should include such components as physical background, characteristics of PDE mathematical model, nonlinear solving method, linear 相似文献
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68.
Summary β-Cyclodextrin sulfate having heparin-mimicking activity was immobilized on a hydrophilic vinyl-polymer gel, TSKgel AF-Epoxy,
TOYOPEARL 650M. A column packed with this material could be used for high-performance affinity chromatographic separation
of heparin-binding substances such as growth factors, enzymes, coagulation factors and lipoproteins. The substances retained
on the column were recovered more easily than those on a heparin-immobilized column. Furthermore, the β-Cyclodextin sulfate-immobilized
gel was superior in stability to the heparin-immobilized gel when exposed to acidic and basic solutions. 相似文献
69.
味觉电化学传感器的研究:甜味物质对模拟生物膜电位振荡的影响 总被引:2,自引:0,他引:2
本文以十六基三甲基溴化铵+乙醇/含苦味酸的硝基苯/蔗糖溶液为研究体系,对影响该体电位振荡的各因进行了探讨,观察到各种甜味物质均能影该体系的振动波形和频率,并发现振荡频率的对数与各甜味物质浓度在一定范围内呈线性关系,初步建立了利用该体系测定甜味物的定笥,定量,工对该味觉电化学传感器的响应机理进行了。 相似文献
70.
杨村煤与石油渣油共处理高温缩聚反应特性的研究 总被引:4,自引:0,他引:4
用GJ-2型微型反应釜研究了兖州杨村煤与石油渣油在470℃时共处理反应的特性,结果表明,杨树煤和石油渣油在高温下进行共处理反应时,宏观表现是缩聚反应占主导地位,程序升温可提高煤的转化率,添加四氢萘到石油渣油中可抑制缩聚反应,而且添加量越大,抑制效果越明显,煤液化产物的重新加氢也会发生一定的缩聚反应,可产生微量结渣。 相似文献