头孢氨苄降解产物荧光性质的研究及分析应用

详细研究了头孢氯苄在酸，碱介质中的降解反应，建立了酸，碱降解的荧光分析法，线性范围是０．５０－１００ｎｇ／ｍＬ（酸降解）和２．０－７０ｎｇ／ｍＬ（碱降解）。从精密度和准确度看，酸降解优于碱降解的荧光分析，将酸降解荧光分析应用于血清和尿样中头氨苄的测定，结果良好。     

Sequential fluorometric quantification of malic acid enantiomers by a single line flow-injection system using immobilized-enzyme reactors

A method for the sequential enantiomeric quantification of d-malate and l-malate by a single line flow-injection analysis was developed using immobilized-enzyme reactors and fluorescence detection. An immobilized d-malate dehydrogenase (d-MDH) reactor and an immobilized l-malate dehydrogenase (l-MDH) reactor were introduced into the flow line in series. Sample and coenzyme (NAD⁺ or NADP⁺) were injected into the flow line by an open sandwich method. d-Malate was selectively oxidized by d-MDH when NAD⁺ was injected with a sample. When NADP⁺ was injected with a sample, l-malate was oxidized only by l-MDH. NADH or NADPH produced by the immobilized-enzyme reactors was monitored fluorometrically at 455 nm (excitation at 340 nm). Linear relationships between the responses and concentrations of d-malate and l-malate were observed in the ranges of 1 × 10⁻⁶-1 × 10⁻⁴ M and 1 × 10⁻⁶-2 × 10⁻⁴ M, respectively. The relative standard deviations for ten successive injections were less than 2% at the 0.1 mM level. This analytical method was applied to the sequential quantification of d-malate and l-malate in fruit juices and soft drinks, and the results showed good agreement with those obtained using conventional method (F-kit method).     

A sequential injection fluorometric procedure for the determination of procaine in human blood and pharmaceuticals

An automated procedure for the assay of procaine hydrochloride in human blood and pharmaceuticals was developed using a sequential injection (SI) technique with fluorometric detection and fluorescamine as the fluorescence probe. A few microliters of fluorescamine and procaine hydrochloride solutions were used in the SI system leading to the formation of a derivative, which was then excited by a 400-nm LED and whose emitted fluorescence was monitored at a wavelength of 494 nm. A linear calibration graph was obtained with 10–200 ng mL⁻¹ (procaine) by loading 10.0 μL of sample solution and 5.0 μL of fluorescamine solution (both 0.125 % m/v). A detection limit of 2.6 ng mL⁻¹, defined as 3 times the blank standard deviation (3σ), was achieved along with a sampling frequency of 25 h⁻¹ and a precision of 2.1 % RSD at the 50.0 ng mL⁻¹ level. Procaine contents in injection solutions from various pharmaceutical manufactures were analyzed and reasonable agreement was achieved between the values obtained by using the present procedure and the documented spectrophotometry, and both were coincident with the nominal concentrations. In addition, the degradation of procaine in human blood was investigated. A fast degradation of procaine in human blood was observed for the first 30 min, while afterwards the degradation was retarded.     

纳米增强型毛细管酶柱用于葡萄糖液滴生物传感器的研究

葡萄糖的检测在临床医学以及食品工业等领域中十分重要.以往的检测方法主要包括化学发光法_{[1]、吸光光度法[2]、电化学法[3]和荧光法[4]等.固定化酶柱的制作是发展葡萄糖传感器的关键技术之一.传统的固定化方法主要是将具有生物活性的酶通过物理吸附、共价键合和交联的方法固定于载体基质上或包埋于有机聚合物的基质中.近期研究[5,6]表明,采用溶胶凝胶(Sol-gel)法将蛋白质和酶等生物活性物质包埋于无机陶瓷或玻璃材料内,保持生物组分的活性,且SiO2作为基质材料具有较好的坚固性、抗磨性、化学惰性以及高的光稳定性和透过性,但目前该法多用于电化学型生物传感器[7,8].本文利用纳米颗粒的比表面积大和吸附能力强等特点,将酶吸附在SiO2纳米颗粒表面,用易成膜的聚乙烯醇缩丁醛(PVB)作辅助基质在毛细管上固定酶,并采用分立式酶柱,克服了以往混合型酶柱普遍存在的酶促效率不高和使用寿命较短的局限性.所制得的酶柱具有表面反应活性高、表面活性中心多和催化效率高等特点.结合自行设计的液滴光化学传感装置[9,10],建立了一种高效、快速、微量的葡萄糖实时检测方法.}     

天然水中痕量铜的荧光测定

8-苯胺基-1-萘磺酸(ANS)可作为蛋白质研究的荧光探针^[1~3],ANS与可溶性的聚乙烯亚胺在微酸性溶液中以缔合物的形式结合,产生强烈的荧光并使ANS在水中的荧光激发和发射光谱分别产生红移和紫移,斯托克斯位移减小.当有痕量铜存在时,聚乙烯亚胺将与铜离子键合成聚合阳离子,它同ANS阴离子生成离子对后,由于ANS微环境极性的增强,导致荧光熄灭^[4],利用这一性质将水中痕量和超痕量的铜用巯基棉分离富集后进行测定,获得了满意结果,铜的检测下限为4.7ppb,对5至100ppb含量范围内铜的测定,相对标准偏不大于2.0%。