稀土铽离子与去甲肾上腺素的荧光反应及其分析应用

实验发现稀土铽离子能与去甲肾上腺素发生络合反应 ,并发射出铽离子的特征荧光。在对铽离子与去甲肾上腺素的络合发光反应进行了详细研究的基础上 ,提出了一种简便、快速、灵敏检测去甲肾上腺素的新方法。在激发波长为 30 0nm ,发射波长为 5 4 5nm处测定其荧光强度 ,去甲肾上腺素浓度在 0 0 1～ 5 0 μg·mL-1范围内与体系的荧光强度具有良好的线性关系 ,相关系数为 0 9990 ,检出限为 1 0ng·mL-1(S/N=3)。该法应用于去甲肾上腺素药物的测定 ,结果令人满意。     

CdSe/ZnS电化学发光法测定去甲肾上腺素

以巯基丙酸为稳定剂制备了水溶性CdSe/ZnS量子点,并采用滴涂法制备了CdSe/ZnS修饰的金电极（CdSe/ZnS/GE）,研究其电化学发光（ECL）性质,考察了pH、CdSe/ZnS浓度、扫描速度、静置时间等实验条件对ECL强度的影响。结果表明,在碱性溶液中,去甲肾上腺素（NE）在鲁米诺溶液中对CdSe/ZnS的电化学发光信号有明显的增敏作用,由此建立了一种检测去甲肾上腺素的新方法。当去甲肾上腺素的浓度（C_NE）在2.3×10^-5~1.0×10^-8 mol/L范围内时,去甲肾上腺素的浓度与相对电化学发光强度呈现良好的线性关系。线性回归方程为ΔI_ECL=118.788C_NE-15.333（R=0.994 4）,最低检测限（S/N=3）为0.33×10^-8 mol/L。     

电化学氧化-荧光分析法测定肾上腺素

通过电化学氧化肾上腺素,使其生成羟基吲哚类荧光物质(λem=490nm),实现了药物中肾上腺素含量的电化学氧化-荧光检测。研究结果表明,荧光强度与肾上腺素浓度分别在2.00×10-7—1.00×10-6mol/L和1.00×10-6—4.00×10-5mol/L范围内呈良好的线性关系,检出限为6.70×10-8mol/L。该方法用于药物制剂中肾上腺素含量的测定,相对标准偏差小于1.88%(n=7),加标回收率为88.4%—116.6%。     

荧光光度法直接测定盐酸异丙肾上腺素的含量

盐酸异丙肾上腺素在伯瑞坦-罗比森缓冲溶液(pH=6.80)介质中有很强的荧光。其最大激发波长和发射波长为287nm和622nm。荧光强度与纯盐酸异丙肾上腺素浓度在0.1—2.3mg/L范围内呈线性关系。回归方程F=351.91C(mg/L) 139.02,r=0.9995,检出限为0.0087mg/L。测定注射用针剂中盐酸异丙肾上腺素的含量,方法简单,快捷,灵敏度高,结果令人满意。     

血浆和组织中皮质酮的荧光测定法

皮质酮是肾上腺皮质激素之一。本文试验研究了用荧光分光光度法测定小哺乳动物血浆和组织中皮质酮含量的方法。方法的线性范围为０．０１－０．２４μｇ／ｍＬ，标准回收率平均为９６．０％，相对标准偏差为４．２％。本法具有快速，准确和灵敏度特点，能同时运用于血浆或肾上腺组织中皮质酮的测定。     

血浆中游离还原型及氧化型谷胱甘肽的荧光测定法

文章建立了快速、可同时检测血浆中游离的还原型和氧化型谷胱甘肽(即GSH和GSSG)的方法, 并评价了血浆中GSH/GSSG的氧化还原状态。利用二硫苏糖醇将GSSG还原成两分子的GSH,使GSH在pH 8.0时与邻苯二甲醛(OPA)结合生成荧光产物GSH-OPA,用荧光分光光度仪测定其荧光值,从而对GSH和GSSG进行定量分析。并运用此方法测量青年健康志愿者静脉血中的游离GSH和GSSG。该法最低可检测出测定管中11.4 pmol·L-1GSH以及5.7 pmol·L-1GSSG。测量GSH批内和批间变异系数分别4.6%和3.9%,GSSG批内和批间变异系数分别为3.5%和4.1%,GSH,GSSG加标准品后的回收率分别为(99.77±5.70)%和(99.28±4.73)%。测定健康青年志愿者血浆中游离GSH,GSSG的含量分别为(16.5±2.4) nmol·mL-1和(1.7±0.35) nmol·mL-1。     

心脏组织的自体荧光研究

测量并研究了家兔心脏组织自体荧光的三维光谱和发射光谱。果表明：冰冻前后心室和心房组织的三维荧光光谱差异较主动脉明显,说明冰冻后其NADH和黄素的含量改变。心房、心室和主动脉组织在340 nm激发光下的自体荧光光谱具有特定的差异,其主要荧光峰位于460 nm 的NADH,以及290～400 nm之间的胶原蛋白和弹性蛋白。根据心房和心室组织的高斯拟和光谱发现,光谱的峰位、相对荧光强度和半宽等参数各不相同。由此,可以根据荧光光谱的谱形和峰强比可以显著区分出不同的心脏组织类型。此外,研究首次发现心室组织NADH的荧光强度会随心肌死亡时间增加而衰减,可作为死亡时间确定的新方法。     

人体胃粘膜组织中过氧化脂质的荧光测定法

本文介绍了用荧光法测定了人体胃粘膜组织中过氧化脂质的含量。该方法用样量少,操作简单,灵敏度高。经回收和重复性实验表明,方法的准确度和精密度均符合要求。     

荧光光谱法测定大鼠组织中辣椒碱的浓度

在激发波长λex=283nm,发射波长λem=320nm下,采用荧光光谱法测定大鼠的几种组织中辣椒碱的浓度.辣椒碱的荧光值基本不受各组织的影响;线性范围为0.01-0.8μg/mL,检出限为5ng/mL;平均回收率均大于90%,RSD均小于7%.该方法快速、简便,适用于辣椒碱的体内研究.     

肿瘤组织自体荧光光谱测量与分析

首先介绍了对人工培养鼠肿瘤组织的激光诱导荧光光谱的实验测量结果，并与同一机体正常组织的自体荧光光谱进行了比较，然后对肿瘤组织自体荧光的来源，与正常组织光谱特征差异的本质进行了详细分析，从而得出结论，生物组织自体荧光光谱能够反映肿瘤组织的特异性，可以作为组织诊断的依据。     

氯氧化锆-氯化铵荧光光谱法测定葡萄糖共存下的果糖

文章根据ZrOCl₂水解产生的[ZrO(OH)]+能与果糖作用产生荧光的原理,建立了果糖的定量测定方法。在NH₄Cl介质中,体系的荧光强度有所增强,产物在408 nm处发荧光,在0.5～25 μg·mL-1范围内荧光强度与果糖浓度成正比,当反应温度为70 ℃、反应时间15 min时,葡萄糖不干扰测定。该法成功用于水果中果糖的测定,灵敏度高,检出限达0.071 μg·mL-1,方法稳定性好,结果满意。     

基于裂开型核酸适体非标记荧光法检测ATP

基于裂开型核酸适体序列短、能有效降低因探针形成二级结构产生假阳性信号等优点,选择裂开型核酸适体作为特异性识别探针,核酸染料噻唑橙（TO）为信号探针,用单壁碳纳米管（SWCNTs）降低背景信号,利用“适配体-目标分子-适配体”的“三明治”夹心方式,建立了一种检测ATP的新方法。在pH 8.0的Tris-HCl缓冲溶液中,裂开成两段的ATP适体特异性识别ATP分子,生成稳定的“适配体-ATP-适配体”复合结构。单壁碳纳米管对该复合结构的吸附力较弱,因此该复合物游离在溶液中,TO与其结合而产生强荧光。当不存在ATP时,核酸适体探针以单链状态存在,可通过π-π共轭作用结合到SWCNTs表面,进而不能与TO结合,TO游离在溶液中荧光非常微弱。反应体系中ATP浓度越高,形成的“适配体-ATP-适配体”夹心识别结构复合物越多,检测到的荧光强度越大,据此实现对ATP的检测。在优化实验条件下,在最大荧光发射波长550 nm处,ATP的浓度在9.0×10-9～1.0×10-7 mol·L-1范围内与ΔF/F₀值成线性关系,r=0.996 4。该方法加标回收率为95.2%～104%,相对标准偏差（RSD）为1.02%～4.54%,检出限达到2.67×10-9 mol·L-1。该方法基于功能核酸对目标物亲合力强、选择识别性高的特点,对ATP的检测表现出很好的选择性,实验结果表明,当相对误差控制在±5%以内时,200倍的UTP,GTP和CTP均不干扰ATP的测定。另外,该方法操作简单、快速、无需标记、灵敏准确,可用于血清样品中ATP的测定,在快速检测小分子物质领域中有较好的应用前景。     

Spectrofluorimetric Estimation of Norepinephrine Using Ethylenediamine Condensation Method

A simple and sensitive method for the determination of norepinephrine is described. Norepinephrine (NE) was oxidized by mercury (II) nitrate and the oxidation product was condensed with ethylenediamine (EDA) to form a strong fluorescent compound. The addition of acetone enhances the light intensity. The measurement was carried out at 507 nm with excitation at 420 nm. A linear relationship was obtained between the fluorescence intensity and norepinephrine concentration in the range of 0.01 μM–0.014 mM; the correlation coefficient and the detection limit are 0.99813 and 2.5 nM, respectively. The interference from dopamine (DA) can be eliminated by first derivative synchronous fluorimetric method using peak to zero technique. The recovery efficiency was performed using known amounts of norepinephrine in urine sample and the results indicate a 95–98.62% recovery. The proposed method was also applied to the determination of norepinephrine in injections solution. The reaction mechanism was also described.     

A Novel Benzimidazole-Based Chemosensor for Fluorometric Determination of Zinc Ions

A simple and novel Schiff base chemosensor (BMHM) based on benzimidazole was synthesized. In ethanol–water (1:1, v/v) medium on varying concentrations of Zn²⁺ chemosensor exhibited a strong and quick turn on fluorescence response. The Zn²⁺ recognition was based on the Chelation–enhanced fluorescence effect. The binding constant and limit of detection for BMHM-Zn²⁺ complexation were estimated to be 7.99?×?104 M^?1 and 0.148 µM, respectively. The extreme fluorescent enhancement caused by Zn²⁺ binding in chemosensor BMHM occurred at a pH range of 6–7. The practical use of chemosensor BMHM was tested by determination of Zn²⁺ in real water samples and comparing the results with the data obtained using high resolution inductively coupled plasma mass spectrometry.

     

A Validated High-Throughput Fluorometric Method for Determination of Omeprazole in Quality Control Laboratory via Charge Transfer Sensitized Fluorescence

A high-throughput 96-microwell plate fluorometric method was developed and validated to determine omeprazole (OMZ) in its dosage forms. The method was based on the charge-transfer (CT) sensitized fluorescence reaction of OMZ with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ). This fluorescence reaction provided a new approach for simple, sensitive and selective determinations of OMZ in pharmaceutical preparations. In the present method, the fluorescence reaction was carried out in 96-microwell plates as reaction vessels in order to increase the automation of the methodology and the efficiency of its use in quality control laboratories. All factors affecting the fluorescence reaction were carefully studied and the conditions were optimized. The stoichiometry of the fluorescence reaction between OMZ and DDQ was determined and the reaction mechanism was suggested. Under the optimum conditions, the linear range was 100–6000 ng/ml with the lowest LOD of 33 ng/ml. Analytical performance of the proposed assay, in terms of accuracy and precision, was statistically validated and the results were satisfactory; RSD was <2.6 % and the accuracy was 98.6–101.6 %. The method was successfully applied to the analysis of OMZ in its dosage forms; the recovery values were 98.26–99.60 ± 0.95–2.22 %. The developed methodology may provide a safer, automated and economic tool for the analysis of OMZ in quality control laboratories.     

基于化学荧光测定的板蓝根抗病毒效价检测方法的建立

荧光测定法在化学分析和生物检测中已广泛应用,将该法引用到中药的生物效价检测中则是一种新的尝试。而生物效价检测与药效直接相关联,是研究中药质量控制与品质评价方法的新趋势。为了建立与抗病毒药效相关的板蓝根质量控制和评价方法,采用化学荧光测定法考察了板蓝根提取物对流感病毒神经氨酸酶(NA)的体外抑制活性,分析了其药理作用的量效曲线变化趋势和作用规律。在此基础上并根据生物检定的统计学原理,以“质反应平行线”法设计和优化检测条件,建立了板蓝根抗病毒生物效价荧光检测方法。实际测试结果能够灵敏、定量表征样品间的品质差异,方法的可靠性和可重复性较好。以此作为板蓝根质量生物控制和评价方法,能够体现中药药效特点。     

荧光光度法测定蜂胶中黄酮

研究了用荧光光度法测定蜂胶中黄酮。以芦丁为标准样品 ,以 4 33nm和 4 95nm为激发和发射波长 ,测定了蜂胶中总黄酮含量。回归方程式为 y=2 .9618+0 .7599× 10 -3x,相关系数 r=0 .9987。方法简便、快速、准确。     

荧光光度法测定二氧化硫的基础研究

利用荧光光度法测定于氧化硫,研究其实验条件的变化对实验结果的影响,并确定它的响应范围。     

Fluorometric and Derivative Spectrophotometric Determination of Norfloxacin

The method for the direct determination of norfloxacin, without prior separation, in serum and pharmaceutical formulations, by means of fluorometry and second derivative u.v. spectrophotometry, was developed. Fluorometric assay of norfloxacin in serum was carried in 0.1 M HCl, with the adition of sodium-dodecylsulphate, at emission wavelength 450 nm (excitation 320 nm). Linear calibration curve was obtained in the concentration range 20 – 320 μg/L with the detection limit 2μg/L. The second derivative spectrophotometry was used for the determination of the norfloxacin in tablets at 337 nm using 0.05 M NaOH as solvent. Detection limit was 30μg/L.     

Second-derivative Synchronous Fluorometric Method for the Simultaneous Determination of Cinnarizine and Domperidone in Pharmaceutical Preparations. Application to Biological Fluids

A rapid, simple and highly sensitive second derivative synchronous fluorometric method has been developed for the simultaneous analysis of binary mixture of cinnarizine (CN) and domperidone (DOM). The method is based upon measurement of the native fluorescence of these drugs at Δλ = 80 nm in aqueous methanol (50% V/V). The different experimental parameters affecting the native fluorescence of the studied drugs were carefully studied and optimized. The fluorescence-concentration plots were rectilinear over the range of 0.1 to 1.3 μg mL⁻¹ and 0.1–3.0 μg mL⁻¹ for CN and DOM, respectively with lower detection limits of 0.017 and 5.77 × 10⁻³ μg mL⁻¹ and quantification limits of 0.058 and 0.02 μg mL⁻¹ for CN and DOM. The proposed method was successfully applied for the determination of the studied compounds in synthetic mixtures and in commercial tablets. The results obtained were in good agreement with those obtained with reference methods. The high sensitivity attained by the synchronous fluorometric method allowed the determination of CN in real and spiked human plasma. The mean % recoveries in case of spiked human plasma (n = 3) were 96.39 ± 1.18 while that in real human plasma (n = 3) was 104.67 ± 4.16.