Formation of Oxygen Vacancies on the {010} Facets of BiOCl and Visible Light Activity for Degradation of Ciprofloxacin

BiOCl nanosheets with oxygen vacancies on the exposed {010} facets were assistant-synthesized by triethanolamine(TEOA) via hydrothermal method. We explored the surface properties, crystal structure, morphology and optical absorption ability of the prepared samples via various characterization technologies. The results indicate that the morphologies and microstructures of the obtained samples depend on the amount of TEOA in the synthesis. The addition of TEOA induces the production of oxygen vacancy on the surface of the samples. Therefore, the synthesized samples with TEOA-assistance hold higher photoactivity for the degradation of colorless antibiotic agent ciprofloxacin(CIP) under visible light(λ ≥ 420 nm). The obtained sample upon the addition of 20 mL of TEOA exhibits the highest photocatalytic performance, which is nearly 14 times as high as that of the sample prepared without TEOA and twice as high as that of the prepared samples with NaOH or NH₃·H₂O. The possible degradation mechanism was discussed on the basis of the experiment results.     

流动注入式乳酸生物传感器

研制了一种测定L－乳酸的生物传感器,将乳酸氧化酶（LOD）通过共价键固定在尼龙钢上制备乳酸氧化酶膜,将制得的酶膜固定在氧电极上构成乳酸生物传感器;将透析膜放在氧化酶膜上产生对L－乳酸扩散高度限制来改变该生物传感器的响应;酶膜机械强度高,在氧电极上反复装卸而不损坏,所构成的乳酸生物传感器的校正曲线的乳酸定量上限达5mmol/L,响应时间小于30s;初步血样测试的结果显示该乳酸生物传感器用于临床血乳酸的测定具有可行性。     

流动注射抑制化学发光法测定盐酸环丙沙星

在碱性介质中,环丙沙星对鲁米诺-KIO4-Co2 反应体系产生的化学发光明显地受到抑制,且化学发光强度的抑制强度与环丙沙星的浓度成正比关系.基于上述现象,提出了环丙沙星的流动注射-化学发光测定法.环丙沙星的质量浓度在3.0×10-7～1.0×10-5g·L-1之间成线性关系,检出限为2.0×10-7g·L-1.对浓度水平为1.0×10-6g·L-1的盐酸环丙沙星进行11次平行测定,得到RSD(n=11)值为2.7%.应用此方法分析了环丙沙星药片,所得结果与按中国药典方法所得测定值保持一致,回收率试验的结果在98.5%～101.2%之间.     

Determination of the antibacterial enrofloxacin by differential-pulse adsorptive stripping voltammetry

Two new methods for the determination of enrofloxacin in commercial formulations and canine urine samples, based on adsorptive stripping voltammetry (AdSV), are proposed. One of the proposed method uses univariate calibration to analyse enrofloxacin in commercial formulations and the other applies principal component regression (PCR) to the voltammetric measurements to determine enrofloxacin in the presence of its metabolite ciprofloxacin. The linear concentration ranges of application were 4-25 and 18-55 ng ml⁻¹ by using an accumulation potential of −0.3 V and a 180 or 60 s accumulation time, respectively for the univariate method. The first concentration range was used for the multivariate method. Both methods were successfully applied to the analysis of commercial formulations and spiked canine urine samples, respectively.     

微波-超声波协同萃取-高效液相色谱检测鱼肉中两种沙星类药物残留

本文报道了微波-超声波协同萃取(MWUS)前处理技术处理样品,高效液相色谱法同时测定鱼肉中环丙沙星(CPFX)和恩诺沙星(ENFX)药物残留的快速分析方法。该法简化了样品的前处理过程,缩短了前处理时间。环丙沙星和恩诺沙星在5～200μg/L范围内,其回收率在76.8%～107.5%之间。     

光散射分析技术测定盐酸环丙沙星含量

在pH 4.6的乙酸-乙酸钠缓冲溶液中,环丙沙星能与四苯硼钠作用生成沉淀产生光散射信号(LS)能应用普通荧光分光光度计检测,从而建立了环丙沙星的光散射分析法.LS光谱在385.0 nm处,具有特征散射峰,且增强的光散射强度(ΔILS)与0.03～0.2 μg/mL,0.2～2.5 μg/mL两个范围内的环丙沙星溶液呈线性关系,相对应的检出限分别为7.4,2.7 ng/mL.本实验中研究了酸度、聚乙二醇600溶液的浓度、四苯硼酸钠溶液的浓度以及共存物质对LS强度的影响.方法已用于盐酸环丙沙星片剂中环丙沙星的测定,RSD为0.3%～0.6%.     

光谱法研究环丙沙星与牛血清白蛋白的相互作用

用荧光光谱法、紫外光谱法研究了生理条件下环丙沙星(CPFX)与牛血清白蛋白(BSA)相互作用的光谱特性。测定了CPFX与BSA在18、28℃两个温度下的结合常数KA(18℃:5.75×105L.mol-1,28℃:1.54×105L.mol-1)和结合位点数n(18℃:0.99,28℃:0.93)。结果表明:CPFX对BSA有明显的猝灭作用,其方式为静态猝灭。由热力学参数分析其结合力主要是氢键和范德华力。同步荧光分析的结果表明CPFX的存在改变了牛血清白蛋白的分子构象。     

Monitoring of extracellular pyruvate, lactate, and ascorbic acid during cerebral ischemia: a microdialysis study in awake gerbils

In vivo microdialysis coupled with liquid chromatography was developed for the continuous monitoring of brain neurochemicals during cerebral ischemia in awake, free moving gerbils. The dead volume of the microdialysis system was estimated to be less than 30 μl. The detection limits of the present assay were 0.2 to 2.0 μM for analytes at a signal to noise ratio of five. To validate this assay, a focal cerebral ischemia was produced by occlusion of one common carotid artery for 60 min and then reperfusion for additional 3 h in awake gerbils. A microdialysis probe was inserted into the striatum of the gerbil. Dialysates were autoinjected and analyzed extracellular pyruvate, lactate, and ascorbic acid by liquid chromatography with a UV detector during cerebral ischemia. Significant changes of pyruvate and the lactate/pyruvate ratio were observed. Biphasic and dynamic changes in ascorbic acid and lactate were proposed to correlate a secondary damage. This assay can be used as a tool to study dynamic changes of brain neurochemicals in awake animals.     

Determination of quinolones by fluorescent excitation emission

In this work the viability of a fluorescent technique for the determination of quinolones is studied. This analytical technique allows one to analyze the effect of the increasing order of the analytical signal from a univariate calibration (zero order data) to partial least squares (PLS) calibration (first order). The comparison has been done through the figures of merit of the analytical procedure (technique and calibration) in accordance with the ISO norm and the 2002/657/EC European Decision about residuals.     

电聚合修饰碳纤维电极及乳酸脱氢酶活性的测定

用电聚合方法将亚甲基绿 (MG)修饰在碳纤维电极 (直径 7μm)上 ,并用该修饰电极测定了乳酸脱氢酶 (LDH)活性。在烟酰胺腺嘌呤二核苷酸 (NAD+ )浓度为 6 .0× 10 - 4mol L ,乳酸浓度为 5 .0× 10 - 3mol/L的pH7.0NaOH KH2 PO4 缓冲介质中 ,电位恒定在 +0 .10V下 ,用电流法测定乳酸脱氢酶活性 ,线性范围为 15～ 2 4 0U/mL ,检测限为 10U/mL ,响应时间为 15s。该修饰微电极稳定性好、灵敏度高、测定干扰小