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介绍了一种在无冷柱头进样器和特殊注射器情况下简便可行的冷柱头进样技术。以海洛因、秋水仙碱、正三十烷醇为研究对象,考察了本方法的定性、定量偏差,提出两种溶质聚焦方法。 相似文献
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Israel S. Ibarra Karina Aguilar-Arteaga Elizabeth Contreras-Lopez Enrique Barrado 《Analytical letters》2013,46(11):1732-1742
A magnetic separation method based on the use of magnetic silica as the stationary phase in sequential injection chromatography was used for simultaneous determination of nonsteroidal anti-inflammatory drugs (acetaminophen, naproxen, diclofenac, and ibuprofen) in tablets. The method is based on a thin layer paramagnetic stationary phase retained on the inner wall of a mini-column through the action of an external magnetic field. The influence of the variables involved was evaluated and the optimal conditions were found to be: a methyl-silica magnetic adsorbent was used as the stationary phase, the mobile phase was methanol-water (60:40, v/v), pH 2.5 adjusted with 98% phosphoric acid, a flow rate 0.60 ml min?1, and UV detection at 225 nm. Under these conditions, the linear range of the calibration curve ranged from 3–6 mg L?1 to 100 mg L?1 with limits of detection ranging between 1 to 2 mg L?1. The proposed method was validated by comparing the results obtained against those provided by high performance liquid chromatography; no significant differences were seen. 相似文献
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《Analytical letters》2012,45(6):905-918
The first sequential injection assay for the generic determination of gabapentin and pregabalin is reported. The analytes react with o-phthalaldehyde in the presence of N-acetylcysteine as a nucleophilic reagent in alkaline medium under flow conditions to form highly fluorescent derivatives. The effect of the main instrumental and chemical variables on the assay was examined. The proposed method was validated for both analytes in terms of linearity, detection, and quantitation limits (c L = 160 μg L?1, c Q = 480 μg L?1 for gabapentin, and c L = 70 μg L?1, c Q = 210 μg L?1 for pregabalin), precision (s r < 1.0% in both cases), selectivity, and accuracy. The applicability of the assay was demonstrated by successfully analyzing commercially available formulations. The experimental percent recoveries were in the range of 97.9–102.0% for gabapentin and 98.3–102.3% for pregabalin. 相似文献
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《Analytical letters》2012,45(21-22):1649-1663
Abstract A rapid and sensitive high-performance liquid chromatographic method for the determination of diclofenac sodium in plasma has been developed. The method is specific and free of interference from metabolites and common anti-inflammatory agents. The UV detector (215 nm) response was linear over a range of 5-1000 ng/ml. Day-to-day and within-day calibration curves were reproducible. The method was validated by analysis of spiked human plasma samples, partly in a blind fashion. The accuracy and precision of the method are satisfactory over the range of 5-1000 ng/ml. The method was cross-checked with the GC method. Results show a correlation coefficient of 0.983 and a slope of 1.04. The method is suitable for the routine analysis of large numbers of plasma samples usually obtained in bioavailability and pharmacokinetic studies. 相似文献
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Joan J. Mateos Enrique Gómez Francesca Garcías Montserrat Casas Víctor Cerdà 《International journal of environmental analytical chemistry》2013,93(6):515-521
A semi-automatic procedure for the simultaneous determination of Ra and Sr in two steps has been developed. In the first step, separation and pre-concentration of both analytes is performed by using a sequential injection procedure. In the second step, the activities of 226Ra and 90Sr, alpha and beta emitters, respectively, are determined using a low background proportional counter at the corresponding plateau potentials. 226Ra concentration is obtained by a single measurement of the precipitate. 90Sr activity is determined by means of its daughter 90Y carrying out two different measurements along the first day after the separation process; the solution of the Bateman radioactivity decay equations allows to obtain the initial 90Sr-90Y activities. The activities analysed in the present work have been ranged between 0-14 Bq/L for 226Ra and 0-175 Bq/L for 90Sr. 相似文献
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《Analytical letters》2012,45(1-3):117-126
A sequential injection methodology with chemiluminescence detection for the evaluation of residual ozone in waters is presented. The procedure is based on the reaction between luminol and ozone without catalysts. Linear calibration plots were obtained for ozone concentrations between 0.05 and 2.0 mg L?1, with a detection limit of 0.04 mg L?1. The developed methodology was applied to the determination of residual ozone in ozonized waters and the results complied with those furnished by the spectrophotometric reference procedure (relative deviations < 6.3%). The method exhibited good precision (RSD < 3.5%) and the sampling rate was about 140 determinations per hour. 相似文献
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Supaporn Kradtap Hartwell Alison Kehling Somchai Lapanantnoppakhun Kate Grudpan 《Analytical letters》2013,46(11):1640-1671
This review focuses on the developments of the various parts of instrumentation and the operation of low to medium pressure flow injection and sequential injection chromatography (FIC and SIC) systems. The report and discussion include solution delivery system, separation column, flow cell and detector, mobile phase management, and online sample pretreatment. Applications of FIC and SIC and their differences as compared to HPLC are also presented. 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - Evaluation of TLC and gel-electrophoresis separations with cameras and image-analysis techniques has been widespread for several... 相似文献
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研制了一种顺序注射尿碘分析仪,将顺序注射技术与催化动力学分析相结合,利用碘对砷-铈氧化还原反应的催化作用,建立了顺序注射尿碘测定方法.采用流速和推吸可控的程控注射器及16孔程控选择阀,实现了顺序注射进样和停留稳态测量.恒温流动池使碘催化的砷-铈反应可以在恒温状态下进行.应用自行设计的微机接口电路和尿碘测定的应用软件,控制反应温度(32.0±0.1)℃,流动配送时间45 s,停流稳定时间60 s,停流检测时间20 s,进样量400 μL.本方法线性范围为15~600 μg/L,检出限为5.01 μg/L(n=11),回收率为94.1%~105.1%.对国家标准参考物质(GBW09109和 GBW09110)的测定结果在给定的标准值范围内.应用本方法检测尿碘并与国家卫生行业标准方法(WS/ T107-2006)进行比较,测定结果无显著性差异(P>0.05). 相似文献
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《Analytical letters》2012,45(5):1375-1387
Abstract The principles of a new sample focusing technique in capillary gas chromatography are described. A solidsorbent trapped sample is thermally released from the sample tube, transfered to a membrane chamber by a carrier gas and there retained by a gas separation membrane which is highly permeable to the carrier gas. After focusing in the membrane chamber the sample is brane chamber geometry to increase the membrane surface and thereby the carrier gas flow is promising too. The major advantage of a membrane focusing system as compared to the cryofocusing technique would be no need for a cooling agent. Such a system would be favourable for hydrocarbon analyses at remote sites. 相似文献
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《Analytical letters》2012,45(1-3):446-456
A novel simple method for separation of vitamins A-acetate (all-trans retinol acetate), D2 (ergocalciferol), or D3 (cholecalciferol) and E-acetate (tocopherol acetate) using short monolithic column in the sequential injection chromatography system is described. Separation was carried out using FIAlab® 3000 system under following conditions: Onyx? Monolithic C18 column (25 × 4.6 mm), mobile phase acetonitrile:methanol:H2O 20:20:1 (v/v/v)), flow rate 0.9 mL min?1, detection at 265 nm (D), 290 nm (E), and 325 nm (A). The method was validated with respect to peak asymmetry, resolution, number of theoretical plates, repeatability, linearity, precision, and accuracy. Analysis time was 5.5 min. 相似文献
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A sequential injection (SI) spectrophotometric method for the determination of oxprenolol in pharmaceutical products was developed. The method is based on the oxidation of oxprenolol on-line with Ce(IV) in sulfuric acid medium and the subsequent monitoring of the absorbance of the oxidized form of the drug at 480 nm. The procedure was optimized by the orthogonal array design at two and four levels. The factors included in the optimization were Ce(IV) concentration, sulfuric acid concentration, and the stop time of the composite zone at the reaction coil. The optimized SI system with a linear dynamic range of 50–400 ppm was found to be suitable for the assay of oxprenolol in pharmaceutical products. 相似文献
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《液相色谱法及相关技术杂志》2012,35(15):3365-3376
Abstract Two injection procedures for open tubular liquid chromatography have been evaluated for their ability to directly sample biological components in minute volumes of body fluids. The techniques provided R.S.D.s in peak heights of less than 12% for injections of low nL volumes of human serum spiked with a test compound. A dynamically modified open tubular column was employed to separate the anti-tumor drug doxorubicin hydrochloride and two of its metabolites. 相似文献
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发展了一种新型进样技术,使样品直接进入位于炉箱内的色谱柱内,样品的汽化,溶质聚焦和分离过程都在炉箱里一次控制完成,不再需要对进样器的温度和其它流量进行控制,极大地简化了进样器的设计和制作 ,改善了定量重复精度,减少了沸点歧视效应在炉箱里一次汽化 相似文献
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离子色谱仪流动注射电导法测定过氧化氢 总被引:2,自引:0,他引:2
以H2S03与H2O2反应生成H2SO4产生的电导变化与H202的量呈线性关系为理论依据,根据流动注射原理将现有离子色谱仪进行改装成流动注射仪测定过氧化氢。此方法有很好的重现性,8次进样所得相对标准偏差小于2.6%,所得结果稳定,其检测下限为0.5mg/L,标准曲线的相关系数达0.9995。本实验对某些分析条件,诸如H2SO3的浓度和流速、样品用量及反应管长度等因素进行了探讨。由于实际样品中存在不同离子而具有不同背景电导,因而在测定实际样品时采用经过过氧化氢酶处理的样品作空白,以此消除背景电导的干扰。 相似文献
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Shah Hiten J. Rathod Ishwarsinh S. Shah Shailesh A. Savale Shrinivas S. Shishoo Chamanlal J. 《平面色谱法杂志一现代薄层色谱法》2003,16(1):36-44
JPC – Journal of Planar Chromatography – Modern TLC - Two fundamentally different analytical methods have been validated and used to monitor release of diclofenac and acetaminophen... 相似文献
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《液相色谱法及相关技术杂志》2012,35(11):2383-2391
Abstract Serum was injected directly on an HPLC column packed with C1, 6.5 μm particle size, 300 Å pore-packing material for carbamazepine determination. The use of a wide-pore column with low hydrophobicity eliminated excessive pressure buildup in the column from protein precipitation which is usually caused by the high concentration of organic solvents in the mobile phase. This simple approach can be utilized for the determination of other drugs and endogenous compounds in serum. 相似文献