FIA-near-infrared spectrofluorimetric trace determination of hydrogen peroxide using tricarchlorobocyanine dye (Cy.7.Cl) and horseradish peroxidase (HRP)

A new kind of near-infrared fluorescence agent, tricarbochlorocyanine dye (Cy.7.Cl), had been synthesized in house and used for near-infrared spectrofluorimetric determination of hydrogen peroxide (H₂O₂) by flow injection analysis (FIA) for the first time. The oxidation reaction of Cy.7.Cl with H₂O₂ occurred under the catalysis of horseradish peroxidase (HRP) and it was studied in detail. The possible reaction mechanism was discussed. Under optimal experimental conditions, fluorescence from Cy.7.Cl displayed excitation and emission maxima (ex/em) at 780 and 800 nm, respectively. The two linear working ranges were 1.86 × 10⁻⁷ to 4.11 × 10⁻⁷ mol L⁻¹ and 4.11 × 10⁻⁷ to 7.19 × 10⁻⁶ mol L⁻¹, respectively. The detection limit was 5.58 × 10⁻⁸ mol L⁻¹ of H₂O₂. The effect of interferences was studied. The proposed method was successfully applied to the determination of hydrogen peroxide in rainwater, serum and plant samples.     

水发食品中痕量甲醛的测定

为建立催化动力学荧光法测定痕量甲醛的新方法,基于在酸性介质中,甲醛催化KBrO3氧化藏红T的褪色反应,使其荧光猝灭的原理,将反应体系在沸水浴中加热8 min,流水冷却3min,采用动力学荧光法测定痕量甲醛。结果表明,甲醛在0.02~0.14μg/mL范围内与△F值呈良好的线性关系,线性方程为△F=-1.642 8+274.12C(μg/mL),r=0.996 9,检出限为0.011μg/mL。该法简便,快速,常见共存物质干扰小,可用于水发食品及其它食品中甲醛含量的测定,加标回收率为84.63%~94.93%。     

β-环糊精与萘普生的包络反应及荧光分析

采用荧光光谱法系统地研究了萘普生的自身荧光现象及其与β-环糊精因包络反应而产生的荧光增敏作用,试验了在不同条件下的荧光性质,提出了测定萘普生含量的高灵敏荧光光度分析新方法. 荧光激发峰λex =229 nm ,荧光发射峰λem = 353 nm ,荧光强度(F)与萘普生的浓度在6.14×10- 8m ol·L- 1 ～1.36×10- 5m ol·L- 1范围内呈线性关系,分析方法操作简便、快速,重现性好,结果令人满意.     

交替三线性分解荧光二阶校正法同时直接测定口服液中氨基酸

酪氨酸(TYR)和色氨酸(TRY)的荧光光谱相互重叠,用常规方法难以同时直接测定。本研究将交替三线性分解二阶校正算法与激发发射矩阵荧光法相结合,对氨基酸口服液中共存的酪氨酸和色氨酸进行了同时分辨和直接定量测定,并用加入标准法对结果进行验证,TYR和TRY的回收率分别为(96.9±2.5)%和(93.2±1.0)%。结果表明,该方法以“数学分离”替代“化学分离”,其它成分及背景不影响其测定。     

偏振—同步荧光法研究

本文叙述一种新的偏振-同步荧光法,该法能有效地抑制同步扫描过程中散射光的影响,从而提高信噪比和改善检测限。以萤光黄、罗丹明6G和罗丹明B混合物为例,采用=βnm的偏振-同步荧光法时,其检测限改善近四倍。     

水杨醛—5—溴—水杨酰腙与锌的高灵敏度荧光反应及其应用

合成了新荧光试剂水杨醛－５－溴－水杨酰腙（ＳＡＢＳＨ），详细研究了试剂与锌的荧光反应新体系的最适宜条件．在ｐＨ７．９的异丙醇／水（体积比１∶１）溶液中，该试剂与Ｚｎ２＋形成配合物，组成比为１∶２（金属∶试剂），λｅｘ／λｅｍ＝３９３ｎｍ／４６５ｎｍ．所建立锌的荧光分析方法的线性范围为０～４００μｇ／Ｌ，相对标准偏差为１．２％，检出限为１．３μｇ／Ｌ．考察了３６种离子的干扰情况．方法成功地用于面粉、大米、人尿和矿泉水中痕量锌的测定．     

二极管阵列检测-激光诱导荧光光度法测定食品中痕量铜

为了建立食品中痕量铜的新分析方法,本文利用自行组装的激光诱导荧光－CCD二极管阵列检测器－计算机联用装置,研究了铜催化H2O2氧化罗丹明B的反应体系,在氨－氟化铵（pH=9.0)缓冲溶液中,激发波长532．0nm,发射波长580．0nm条件下,采用催化荧光光度法实现了食品样品中痕量铜的测定,方法的线性范围0．5－4．0ug/L,方法的检出限为0.5ug/L,加标回收率为86．9％－108．6％,s相对偏差不大于9．70％。     

The Use of β-Cyclodextrin Inclusion Complexes for the Analysis of Bisphenol a Residues in Water by Spectrofluorimetry

Abstract

The application of β-cyclodextrin inclusion complexes to determine trace levels of bisphenol A (BPA) in aqueous solution by spectrofluorimetry was investigated. A 1:1 stoichiometry of the host-guest complex between β-CD and BPA, as well as the association constant was determined by using the changes in the fluorescence of BPA that occur when it is included in the hydrophobic cyclodextrin cavity. A simple and sensitive spectrofluorimetric method for the determination of BPA residues is presented; the applicable concentration range was 10.0 to 200.0 μgL^?1. The detection limit obtained was 0.5 μg.L^?1. The accuracy of the proposed method, was checked in the analysis of water samples from different sources previously spiked with different amounts of BPA.     

偏振-同步荧光法同时测定(艹屈)、蒽和苝

在荧光分光光度计的激发和发射光路中分别置入偏振互为垂直的偏振片,能有效地抑制同步扫描过程中散射光的影响。建立了(艹屈)蒽和苝的同时偏振-同步荧光分析法,其检出限改善3.9倍,相对标准偏差小于3.1%。     

Gatifloxacin-铕荧光探针测定DNA

在pH 7.0±0.1的Tris-HCl缓冲溶液中,Eu3 与加替沙星形成的络合物受270 nm紫外光激发发出Eu3 的特征荧光峰,加人脱氧核糖核酸(DNA)能大大增强体系的荧光强度,由此建立GFLX-Eu3 络合物探针测定核酸的方法.与GFLX-Eu3 二元络合物相比.GFLX-Eu3 -DNA三元体系荧光强度显著增强,且最大吸收波长紫移5 nm,表明形成三元络合物.研究了反应的最佳条件,并初步探讨了GFLX-Eu3 络合物探针和DNA结合机制.