酶催化荧光光谱法测定盐酸多巴胺

利用盐酸多巴胺对血红蛋白酶催化荧光体系的猝灭作用,建立了酶催化荧光光谱法测定盐酸多巴胺的新方法.研究了该猝灭体系的最佳实验条件及动力学行为,测定的线性范围为2.1×10-8--8.4×10-4mol/L,检出限为8.2×10-9mol/L.对浓度为5.2×10-6mol/L的盐酸多巴胺进行11次平行测定,其相对标准偏差...     

Determination of Floctafenine in Presence of its Degradation Product Floctafenic Acid by Direct and Synchronous Spectrofluorimetry

ABSTRACT

A simple, rapid and sensitive spectrofluorimetric method for the determination of floctafenine I (FL) in the presence of its degradation product floctafenic acid II (FLA) is developed. The method involves measuring the fluorescence intensity of FL in acetonitrile and in the presence of triethylamine (TEA) at an emission wavelength of 470 nm (excitation at 360 nm) by direct spectrofluorimetry and at an emission 465 nm (excitation 355 nm) by synchronous spectrofluorimetry. At these conditions FLA does not interfere. FLA is determined alone by measuring the fluorescence intensity of its solution in acetonitrile, without addition of TEA, at emission wavelength 460 nm (excitation 355 nm). The proposed method has been used for the assay of FL in tablets, plasma, urine and in mixtures with FLA. It gave highly accurate results for recovery of FL in the presence of its related acid.     

Spectrofluorimetric Determination of Germanium Traces Using 1,2,4-Trihydroxyantraquinone

ABSTRACT

A new spectrofluorimetric method for determination of germanium traces based on its reaction with 1,2,4-Trihydroxyantraquinone, at an apparent pH 8.8 provided by an ammonia/ammonium chloride buffer, in a 80:20(v/v) ethyleneglycol water medium is proposed. The calibration graph is linear over the range 70–725 ng/ml and features a detection limit of 2.5 ng/ml. The effect of potential major interferences has been investigated and the proposed method was successfully applied to the determination of germanium in synthetic samples and industrial concentrates, after extraction with CCl₄, in an 9 M HCl medium.     

Flow Injection Analysis Determination of Ascorbic Acid with Spectrofluorimetric Detection

Abstract

A flow injection system for the fluorescence determination of low level of ascorbic acid is proposed. The method is based on the rapid oxidation of ascorbic acid by thallium(I). The fluorescence signal at 419 nm is proportional to the amount of ascorbic acid in the range of (1.4–28.0) × 10^?7 mole. The relative standard deviations for ten replicate measurements of 1.4 × 10^?6 mole of ascorbic acid was 1.3%. The sample rate of 45 ± 5 sample per hour was achieved. The usefulness of the method was tested in the determination of ascorbic acid in fruit juices and vitamin C tablets.     

荧光分光光度法同时测定多元素的研究──以P－矩阵法计算混合体系中痕量磷和砷

本文研究了磷，砷钼杂多酸－罗丹明６Ｇ荧光猝灭反应，以Ｐ－矩阵计算混合体系中痕量磷和砷。本法灵敏度高，选择性好，简便快速，应用于铜合金中的痕量磷和砷测定，获得满意结果。     

Simultaneous fluorimetric determination of glyphosate and its metabolite, aminomethylphosphonic acid, in water, previous derivatization with NBD-Cl and by partial least squares calibration (PLS)

The reactions of 4-chloro-7-nitrobenzofurazan (NBD-Cl) with glyphosate (GLY) and with its main metabolite, aminomethylphosphonic acid (AMPA), have been studied. The resolution of binary mixtures of glyphosate and aminomethylphosphonic acid has been accomplished by partial least squares (PLS) multivariate calibration. The method of determination is based on the fluorescence emission of the derivatives formed in presence of NBD-Cl at 90 °C, in methanol and in basic medium. The dynamic ranges of the methods were comprised between 10 and 150 μg l⁻¹ for GLY and between 10 and 200 μg l⁻¹ for AMPA, being the detection limits 2 and 5.4 μg l⁻¹ for GLY and AMPA, respectively. The total luminiscence information of the derivatives has been used to optimize the spectral data set to perform the calibration, by analysis of the three-dimensional excitation-emission matrices. A comparison between the predictive ability of the multivariate calibration method, partial least squares type 1 (PLS-1), on two spectral data sets, emission and synchronous spectra, has been performed. The PLS-1 method, applied to the emission spectra, has been selected as optimum. The proposed method has been applied to the simultaneous determination of GLY and AMPA in river water. For concentrations ranging from 100 to 600 μg l⁻¹ of each compound in the samples, analytical recoveries range from 83 to 94% for GLY and from 104 to 120% for AMPA.     

以碘为受体的荷移络合物的荧光光谱研究及应用

采用荧光光谱法研究了诺氟沙星与碘形成荷移络合物的荧光性质,发现碘对诺氟沙星有强烈的荧光增敏效应。据此,建立了一种高灵敏的测定诺氟沙星的荷移荧光光谱新方法。优化了影响反应的不同变量和参数,在最佳实验条件下,方法线性范围为0.04~1.5μg/mL,检出限为0.01μg/mL。该方法用于药物制剂中诺氟沙星含量的测定,其回收率为98.09%~99.97%。     

稀土元素悬浮液荧光体系的研究——铕-钆-二本甲酰甲烷-二乙胺体系

系统研究了明胶对铕-钇-二苯甲酰甲烷-二乙胺沉淀悬浮液荧光体系的稳定化作用和钆对铕的荧光增强效应,使荧光强度提高约2个数量级,Eu的检出限达8.5×10~(-13)mol/L(k=3),该体系可用于Gd_2O_2中痕量Eu的测定,结果满意.     

Spectrofluorimetric determination of aliphatic amines using a new fluorigenic reagent: 2,6-dimethylquinoline-4-(N-succinimidyl)-formate

A new amino fluorescence probe, 2,6-dimethylquinoline-4-(N-succinimidyl) formate (DMQF-OSu) has been synthesized. Based on the selective reaction of DMQF-OSu with primary and secondary aliphatic amines to yield strong fluorescence, a new spectrofluorimetric method for the determination of total aliphatic amines has been developed. At λ_ex/λ_em=324.4/416 nm, the linear calibration range was 6×10⁻⁸-6×10⁻⁶ mol l⁻¹ with the detection limit (3σ) of 1.94×10⁻¹⁰ mol l⁻¹ for the determination of aliphatic amines in weak basic media. The proposed method has been applied to the determination of aliphatic amines in tap water and lake water with the recoveries of 99-104%. Compared with the reported methods, the method presented here is rapid, simple, sensitive and feasible.     

Indirect determination of superoxide anion radical in the plant of red sage based on vanillin-8-aminoquinoline with fluorescence

A novel spectrofluorimetric method using vanillin-8-aminoquinoline (VAQ) as fluorescent probe was developed for the determination of superoxide anion radical (O₂⁻). The new fluorescent probe was characterized by elemental analysis and IR spectra. Under the optimum conditions of the determination, the linear calibration range and the detection limit of the developed method for superoxide anion radical were in the range (0.0-1.0)×10⁻⁵ and 2.0×10⁻⁸ mol l⁻¹, respectively. The effect of interferences was studied. The proposed method was applied to determine the generation rate of superoxide anion radical in the course of aging in red sage successfully.