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Ultrasonic extraction followed by sonolysis-ozonolysis as a sample pretreatment method for determination of reactive arsenic toward sodium tetrahydroborate by flow injection-hydride generation AAS

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ANALYTICAL CHEMISTRY 2001年第15期73卷 3732-3736页

作者： Capelo, JL Lavilla, I Bendicho, C Univ Vigo Fac Ciencias Quim Dept Quim Analit & Alimentaria Vigo 36200 Spain

A new sample pretreatment method based on ultrasonic extraction in HCl medium and subsequent oxidation of the extracts by sonozone (i.e., sonolysis-ozonolysis) has been developed for determination of reactive arsenic toward sodium tetrahydroborate [mainly As(III) + As(V)] by flow injection-hydride generation atomic absorption spectrometry. This method avoids the use of intensive treatments with concentrated and corrosive acids, high pressures, and temperatures that are inherent with traditional wet or dry ashing procedures and entails reduced waste production and reagent consumption. A sonozone process at room temperature was optimized to break the bond of As to proteins and macromolecular constituents which was an essential requirement for effective reduction by L-cysteine prior to arsine generation. Spiking experiments showed that As(III), As(V), MMA, and DMA were fully recovered from several matrixes on applying the above treatment. On the other hand, a nonreducible As species such as arsenobetaine that is predominant in some biological samples remained unchanged. Application of the method to sediment, soil, fly ash, and plant CRMs demonstrated that, in general, a good agreement existed between certified and found As contents, thereby indicating the absence of nonreducible As forms. Low As recoveries were observed for fish CRMs, as a result of the nondegradability of arsenobetaine by sonozone. The detection limit of As in the samples investigated was in the range 0.19-2.8 mug g(-1).

关键词：砷/分析砷剂/分析氢硼化物/化学半胱氨酸/化学鱼类流动注射分析/方法海螯虾科氧化还原臭氧/化学分光光度法原子超声学动物

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Detection in the liquid phase applying chemiluminescence

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BIOMEDICAL CHROMATOGRAPHY 2000年第3期14卷 166-172页

作者： García-Campaña, AM Baeyens, WRG Zhang, XR Smet, E Van der Weken, G Nakashima, K Calokerinos, AC Univ Granada Fac Sci Dept Analyt Chem E-18071 Granada Spain State Univ Ghent Fac Pharmaceut Sci Dept Pharmaceut Anal Lab Drug Qual Control B-9000 Ghent Belgium Tsing Hua Univ Dept Chem Anal Ctr Beijing 100084 Peoples R China Nagasaki Univ Sch Pharmaceut Sci Nagasaki 852 Japan Univ Athens Dept Chem Analyt Chem Lab Athens 15771 Greece

Several chemiluminescence-based reactions are applicable to the determination of various bio-pharmaceutically important analytes, and they can be applied for monitoring chemiluminescence emission using flow injection, liquid chromatographic and capillary electrophoretic analysis, as well as for the development of chemiluminescence-based sensors or in immunoassays. As in general the emission intensity is linearly proportional to the concentration of any of the reagents, the technique allows the analysis of different species involved in the light-producing reaction, amongst which are the chemiluminescent reagent, oxidants, inhibitors, cofactors, catalysts, some fluorophore, etc. The present overview illustrates some important applications of the last decade on this rather unfamiliar luminescence technique to detectional challenges in the liquid phase. The required instrumentation is limited as no external light source is needed. Also, the technique opens perspectives for increasing detection sensitivity in miniaturized flowing streams. On the other hand, several drawbacks still limit full application, eg dependence of the emission signal upon a number of environmental factors forcing the analyst to make a compromise between separating and measuring conditions, a lack of selectivity in specific cases, the critical detection of the signal at strictly defined periods, especially in the case of sharp emission vs time profiles, and the development of detection devices in capillary electrophoresis. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词：化学发光测定法化学分析/方法色谱法液相/方法电泳毛细管/方法流动注射分析/方法免疫测定/方法指示剂和试剂氧化剂药用制剂/分析人类

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A reusable and specific protein A-coated piezoelectric biosensor for flow injection immunoassay

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BIOTECHNOLOGY PROGRESS 2000年第1期16卷 116-124页

作者： Lu, HC Chen, HM Lin, YS Lin, JW Natl Taiwan Univ Sci & Technol Dept Chem Engn Taipei 106 Taiwan Chang Gung Univ Dept Chem Engn Tao Yuan 333 Taiwan

A hydrophilic matrix of periodate-oxidized dextran was used as a double-sided linker to covalently immobilize Staphylococcus aureus protein A (SpA) molecules onto a poly-L-lysine-modified piezoelectric crystal surface to improve their stability, activity, and binding specificity with human immunoglobulin G (IgG) in flow injection assays. The prepared sensing crystals displayed best sensitivity and reusability at a flow rate of 140 mu L/min. A human IgG concentration as low as 0.3 nM can be detected by this system. Up to 19 successive assay repetitions were achieved without significant loss of sensitivity using the same crystal. The analysis of adsorption kinetics indicates that such a preparation can greatly increase the amount of available active human IgG binding sites on immobilized SpA. Hardly any response arising from unspecific binding was detected. In addition, the sensing crystal prepared by this method was found to retain activity better than one prepared via direct deposition when stored in either wet or dry states. Finally, the prepared SpA-coated crystals were applied to the affinity immobilization of polyclonal goat anti-Schistosoma japonicum glutathione-S-transferase (GST) and were able to subsequently detect GST and its genetically engineered mutant either in a purified form or in the crude cell lysate.

关键词：抗体蠕虫生物传感技术生物技术设备重复使用大肠杆菌/遗传学流动注射分析/方法谷胱甘肽转移酶/分析谷胱甘肽转移酶/遗传学谷胱甘肽转移酶/免疫学免疫测定/方法免疫球蛋白G/分析免疫吸附技术重组蛋白质类/分析重组蛋白质类/遗传学重组蛋白质类/免疫学血吸虫日本/酶学血吸虫日本/遗传学血吸虫日本/免疫学葡萄球菌蛋白质A 动物人类

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Flow injection monitoring and analysis of mixtures of hydrazine compounds using filter-supported bilayer lipid membranes with incorporated DNA

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ANALYTICAL CHEMISTRY 2000年第1期72卷 180-186页

作者： Siontorou, CG Nikolelis, DP Krull, UJ Univ Athens Dept Chem Analyt Chem Lab GR-15771 Athens Greece Univ Toronto Dept Chem Chem Sensors Grp Mississauga ON L5L 1C6 Canada

This work describes a technique for the rapid and sensitive electrochemical flow injection monitoring and analysis of mixtures of hydrazine compounds using stabilized systems of filter-supported bilayer lipid membranes (BLMs) composed of egg phosphatidylcholine (egg PC) with incorporated DNA. Injections of hydrazines were made into flowing streams of a carrier electrolyte solution, and a transient current signal with a duration of seconds reproducibly appeared in less than one min after exposure of the DNA-modified lipid membranes to the hydrazines. The magnitude of this signal was linearly related to the concentration of hydrazines, which could be determined at sub-micromolar levels. Repetitive cycles of injection of hydrazines have shown no signal degradation during each cycle (30 sequential injections), The time of appearance of the transient response was different for each hydrazine and increased in the order of hydrazine, methylhydrazine or dimethylhydrazine, and phenylhydrazine. The difference in time of response has snowed selective detection and analysis of these hydrazines in mixtures.

关键词： DNA/化学电化学/方法过滤/仪器和设备流动注射分析/方法肼类/分析脂双层/化学

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Polymerization of rod-like macromolecular monomers studied by stopped-flow, multiangle light scattering: Set-up, data processing, and application to fibrin formation

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BIOPHYSICAL JOURNAL 2000年第1期79卷 561-583页

作者： Bernocco, S Ferri, F Profumo, A Cuniberti, C Rocco, M Ctr Biotecnol Avanzate Grp Biostruct I-16132 Genoa Italy Ctr Biotecnol Avanzate Ist Nazl Ric Canc Serv Biol Mol I-16132 Genoa Italy Univ Genoa Dipartimento Chim & Chim Ind I-16146 Genoa Italy Univ Insubria Como Dipartimento Sci Chim Fis & Matemat I-22100 Como Italy INFM I-22100 Como Italy

Many biological supramolecular structures are formed by polymerization of macromolecular monomers. Light scattering techniques can provide structural information from such systems, if suitable procedures are used to collect the data and then to extract the relevant parameters. We present an experimental set-up in which a commercial multiangle laser light scattering photometer is linked to a stopped-flow mixer, allowing, in principle, the time-resolved extrapolation of the weight-average molecular weight M-w and of the z-average square radius of gyration [R-g(2)](z) of the polymers from Zimm-like plots. However, if elongated structures are formed as the polymerization proceeds, curved plots rapidly arise, from which M-w and [R-g(2)](z) cannot be recovered by linear fitting. To verify the correctness of a polynomial fitting procedure, polydisperse collections of rod-like or worm-like particles of different lengths, generated at various stages during bifunctional polycondensations of rod-like macromolecular monomers, were considered. Then, the angular dependence of their time-averaged scattered intensity was calculated in the Rayleigh-Gans-Debye approximation, with random and systematic noise also added to the data. For relatively narrow size distributions, a third-degree polynomial fitting gave satisfactory results across a broad range of conversion degrees, yielding M-w and [R-g(2)](z) values within 2% and no greater than 10-20%, respectively, of the calculated values. When more broad size distributions were analyzed, the procedure still performed well for semiflexible polymers, but started to seriously underestimate both M-w and [R-g(2)](z) when rigid rod-like particles were analyzed, even at relatively low conversion degrees. The data were also analyzed in the framework of the Casassa approximation, from which the mass per unit length of the polymers can be derived. These procedures were applied to a set of data taken on the early stages of the thrombin-catalyzed p

关键词：色谱法高压液相计算机模拟评价研究(主题) 纤维蛋白/化学合成纤维蛋白/化学纤维蛋白原/化学纤维蛋白原/分离和提纯流动注射分析/仪器和设备流动注射分析/方法光模型理论聚合物/化学试验预期值回归分析可重复性结果散射辐射信号处理计算机辅助人类

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Flow injection spectroscopic analysis of model drugs using on-line UV-diode array, FT-infrared and ¹H-nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry

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ANALYST 2000年第5期125卷 927-931页

作者： Louden, D Handley, A Taylor, S Lenz, E Miller, S Wilson, ID Sage, A AstraZeneca Pharmaceut Macclesfield SK10 4TG Cheshire England LGC Runcorn WA7 4QD Cheshire England Micromass UK Ltd Manchester M23 9LZ Lancs England

A prototype flow injection analysis (FIA) system for the characterisation of compounds via a combination of diode array UV, H-1 NMR, FT-IR spectroscopy and time-of-flight (TOF) mass spectrometry has been investigated using a number of pharmaceuticals and related compounds as model compounds. This combination of spectrometers allowed the on-flow collection of UV, H-1 NMR, IR and mass spectra together with atomic composition data, enabling almost complete structural characterisation to be performed. Practical detection limits with the current system were in the region of 50 mu g, however, the use of state of the art spectrometers would result in a significant reduction in the amount of material required.

关键词：流动注射分析/方法磁共振波谱学/方法质谱分析法/方法药用制剂/分析

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A flow injection renewable surface technique for cell-based drug discovery functional assays

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ANALYTICAL CHEMISTRY 1999年第6期71卷 1160-1166页

作者： Hodder, PS Ruzicka, J Univ Washington Dept Chem Seattle WA 98195 USA

A novel now injection-renewable surface (FI-RS) technique is introduced for the execution of automated pharmacology-based assays on living cells. Cells are attached to microcarrier beads, which serve as the disposable and renewable surface with which the assay-is performed. The feasibility of this FI-RS technique is demonstrated by performing a functional assay using Chinese hamster ovary cells transfected with the rat muscarinic receptor (M1). The intracellular calcium elevation resulting from the agonist-receptor interaction is measured via a calcium-sensitive fluorescent probe (fura-2) and a fluorescence microscope photometry system. The FI apparatus allows reproducible and precise control of the concentration gradient of chosen muscarinic receptor agonists (carbachol, acetylcholine, pilocarpine) delivered to cells attached to microcarrier beads. The RS methodology eliminates problems associated with diminishing biological response vis-a-vis traditional functional assays that are performed repetitively on the same group of cells. Using this technique, reproducible responses are measured and pharmacologic parameters quantified that compare favorably to literature values. In addition, the use of the FI-RS functional assay as an analytical method for discrimination of agonists based on kinetic parameters is proposed.

关键词： CHO细胞仓鼠亚科流动注射分析/方法荧光染料动力学毒蕈碱激动剂/分析动物大鼠

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Immunoaffinity layering of enzymes - Stabilization and use in flow injection analysis of glucose and hydrogen peroxide

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APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 1999年第3期52卷 373-379页

作者： Farooqi, M Sosnitza, P Saleemuddin, M Ulber, R Scheper, T Univ Hannover Inst Tech Chem D-30167 Hannover Germany Aligarh Muslim Univ Fac Life Sci Dept Biochem Aligarh 202002 Uttar Pradesh India

A general procedure for the high yield immobilization of enzymes with the help of specific anti-enzyme antibodies is described. Polyclonal antibodies were raised against Aspergillus niger glucose oxidase and horseradish peroxidase in rabbits and the gamma globulin (IgG) fraction from the immune sera isolated by ammonium sulphate fractionation followed by ion-exchange chromatography. Immobilization of glucose oxidase and horseradish peroxidase was achieved by initially binding the enzymes to a Sepharose matrix coupled with IgG isolated from anti-(glucose oxidase) and anti-(horseradish peroxidase) sera, respectively. This was followed by alternate incubation with the IgG and the enzyme to assemble layers of enzyme and antibody on the support. The immunoaffinity-layered preparations obtained thus were highly active and, after six binding cycles, the amount of enzyme immobilized could be raised about 25 times over that bound initially. It was also possible to assemble layers of glucose oxidase using unfractionated antiserum in place of the IgG. The bioaffinity-layered preparations of glucose oxidase and horseradish peroxidase exhibited good enzyme activities and improved resistance to heat-induced inactivation. The sensitivity of a flow injection analysis system for measuring glucose and hydrogen peroxide could be remarkably improved using immunoaffinity-layered glucose oxidase and horseradish peroxidase. For the detection of glucose, a Clark-type oxygen electrode, constructed as a small flow-through cell integrated with a cartridge bearing immunoaffinity-layered glucose oxidase was employed. The hydrogen peroxide concentration was analysed spectrophotometrically using a flow-through cell and the layered horseradish peroxidase packed into a cartridge. The immunoaffinity-layered enzymes could be conveniently solubilized at acid pH and fresh enzyme loaded onto the support. Immunoaffinity-layered glucose oxidase was successfully used for the on-line monitoring of the gluco

关键词：抗体真菌/免疫学曲霉菌黑/酶学校准色谱法亲和/方法电极酶类固相流动注射分析/仪器和设备流动注射分析/方法真菌蛋白质类/免疫学真菌蛋白质类/代谢葡萄糖/分析葡糖氧化酶/免疫学葡糖氧化酶/代谢辣根过氧化物酶/免疫学辣根过氧化物酶/代谢过氧化氢/分析氢离子浓度免疫血清免疫球蛋白G/免疫学免疫吸附技术植物蛋白质类/免疫学植物蛋白质类/代谢敏感性与特异性分光光度法温度动物兔

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Flow injection determination of vitamin K₃ by a photoinduced chemiluminescent reaction

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ANALYST 1999年第2期124卷 197-201页

作者： Pérez-Ruíz, T Martínez-Lozano, C Tomás, V Martín, J Univ Murcia Fac Chem Dept Analyt Chem E-30071 Murcia Spain

The determination of vitamin K-3 using the coupling between a photochemical reaction and a chemiluminescent reaction in a flow system is described. The method is based on the photooxidation of ethanol sensitized by vitamin K-3 to yield hydrogen peroxide, which is monitored through the chemiluminescent reaction with luminol catalysed by hematin. The new approach allows the determination of vitamin K-3 in a wide concentration range (1 x 10(-7)-5 x 10(-4) mol l(-1)) with a throughput of 30 samples h(-1). The applicability of the method was demonstrated by the determination of vitamin K-3 in pharmaceutical preparations.

关键词：流动注射分析/方法止血药/分析发光测定法维生素K/分析人类

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Flow injection Fourier transform infrared determination of nicotine in tobacco

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ANALYST 1999年第5期124卷 783-786页

作者： Garrigues, JM Pérez-Ponce, A Garrigues, S de la Guardia, M Univ Valencia Dept Analyt Chem E-46100 Burjassot Valencia Spain

A fully automated procedure is proposed for the Fourier transform infrared (FTIR) determination of nicotine in tobacco. The method is based on the on-line extraction of nicotine with CHCl3. Samples, weighed inside empty extraction cartridges, were humidified with NH3 and the cartridges were installed in a flow manifold in which they were extracted with 2 ml CHCl3 for 2 min, then 400 mu l of the extract were introduced into a micro-flow cell using a carrier of CHCl3 and the DR spectrum was registered continuously. The absorbance, in the wavenumber range 1334-1300 cm(-1), was measured, obtaining a peak as a function of time. The area of this peak was interpolated on a calibration line established from Standard solutions of nicotine in chloroform treated in the same way as samples. The method provided a limit of detection of 0.1 mg ml(-1) nicotine, an RSD lower than 2% and a sampling frequency of the whole procedure of 6 h(-1). Results obtained for natural samples of cut tobacco and cigar compared well with those obtained by a batch FTIR procedure, involving an off-line extraction with a total time of 16 min. However, for yellow tobacco cigarette, an on-line extraction time of 10 min was required to obtain a good recovery of nicotine.

关键词：流动注射分析/方法傅里叶分析尼古丁/分析植物有毒烟草/化学人类

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