蒽醌衍生物在痕量汞固体基质室温燐光猝灭法测定中的应用

该文合成了2,3-二氢-9,10-二羟基-1,4-蒽醌(R),并借助核磁共振谱、红外光谱、质谱及紫外光谱等方法确定其结构.基于R在醋酸纤维素膜固体基质上能产生强而稳定的固体基质室温燐光(SS-RTP),α,α'-联吡啶可活化Hg2+催化H2O2氧化R转化成无燐光化合物,导致固体基质室温燐光急剧猝灭,建立了催化H2O2氧...     

动力学荧光猝灭法测定痕量铜

研究了在稀盐酸介质中，铜（Ⅱ）催化过硫酸钾氧化磺化钾，生成的Ｉ＾－３与罗丹明６Ｇ生成缔合物而使罗丹明，６Ｇ荧光猝灭，建立了催化荧光法测定痕量铜的方法，线性范围为４－５４检出限为１．６μｇ／Ｌ。     

硫化镉纳米荧光探针荧光猝灭法测定痕量铜

制备了无机纳米溶胶CdS，研究了纳米粒子的大小和荧光性质，以该纳米粒子为探针，建立了荧光猝灭法测定铜离子的新方法。该方法已成功用于人发样品测定，方法简单，快速，选择性好，灵敏度高，在最佳实验条件下，测定铜离子的线性区间为2．0－24．0μg/L，检出限为0．23μg/L。     

荧光猝灭法测定痕量砷?

根据在稀盐酸介质中,碘酸钾可与As?发生氧化还原反应生成I2,I2与荧光试剂吡咯红Y作用,使其荧光猝灭,提出了一种新的测定痕量As?的荧光分析法.该方法的线性范围为24.0～248 μg/L,检出限为14.1 μg/L,方法用于自来水、尿液、血清及合成样中痕量As?的测定,均获得满意结果.     

催化碘酸钾氧化异硫氰酸荧光素荧光猝灭法测定痕量硒

基于异硫氰酸荧光素(FITC)可发射强而稳定的荧光信号,KIO3能氧化FITC而发生荧光猝灭,Se(Ⅳ)使FITC的荧光强烈猝灭,Se(Ⅳ)的含量与ΔF值呈线性关系,建立催化KIO3氧化FITC荧光猝灭法测定痕量硒的新方法.方法的线性范围为0.012～2.000×10-15g Se(Ⅳ)/mL,工作曲线回归方程ΔF=1.18+72.74CSe(Ⅳ)(×10-15g/mL)(n=6,r=0.9997),检出限为2.1×10-18g/mL(n=11).分别对Se(Ⅳ)浓度0.012和2.000×10-15g/mL进行7次测定,RSD依次为2.8%和3.5%.用于实际样品中痕量硒的测定和人体疾病的诊断与预报,结果满意.同时探讨了催化荧光猝灭法测定痕量硒的反应机理.     

二溴苯基荧光酮荧光猝灭法测定铟

１引言自１９７８年合成了４，５－二溴苯基荧光酮（简称ＤＢＰＦ）以来，ＤＢＰＦ作为一种高灵敏显色剂得到了广泛的应用。该试剂在胶束增溶光度分析中灵敏度非常高，广泛用于光度法测定金属离子。但利用ＤＢＰＦ作为荧光剂测定痕量Ｉｎ（Ⅲ）的方法尚未见报道。本文研究了在表面活性剂ＣＴＭＡＢ存在下·Ｉｎ（Ⅲ）与ＤＢＰＦ的荧光猝灭体系，在ｐＨ４.０的ＨＣｌ／ＮａＡｃ介质中，以４００ｎｍ为激发波长，体系在５３５ｎｍ处荧光强度达到最大，痕量钢的加入对该体系荧光有很强的猝灭作用。在０～１６０μｇＩｎ（Ⅲ）／Ｌ范围内呈线性…     

荧光猝灭法测定痕量亚硝酸根

研究了用荧光猝灭法测定了亚硝酸根。本方法是基于亚硝酸根与碘化钾反应生成了单质碘,碘可以使２’,７’０二氯荧光素（ＤＣＦ）发生荧光猝灭,从而间接测定亚硝酯根。亚硝酸根浓度在１０￣１２０μｇ／Ｌ范围内,荧光强度差值与亚硝酸根浓度呈线性关系。检测限为５．６μｇ／Ｌ。本法简便、灵敏度较高,已用于合成样和分析纯试剂中亚硝酸根的测定。     

吖啶红荧光猝灭法测定痕量硒

在稀盐酸溶液中,Se(Ⅳ)与碘化钾反应生成碘分子,碘分子与吖啶红反应,使其发生荧光猝灭反应,荧光猝灭值在一定范围内与硒(Ⅳ)浓度呈线性关系,据此建立了测定痕量硒的荧光猝灭方法。方法的测定范围为0.01～O.20μg·ml-1。方法用于金属锰中痕量硒的测定,结果满意。     

2,3,4,9-四氢-9-羟基-1,10-蒽醌的合成及荧光猝灭法测定痕量砷

荧光动力学分析法常以罗丹明类、荧光素类、桑色素等作为指示物,用蒽醌作为指示物较少见。本文报道了以2,3,4,9-四氢-9-羟基-1,10-蒽醌(简称R)为指示物,荧光动力学分析法测定痕量砷的新方法。实验直接用硼酸代替三氯化铝加硫酸封环一步法制得1,4-二羟基-9,10-蒽醌,再经冰醋酸和     

荧光猝灭法测定痕量亚硝酸根

基于在酸性介质中,NO-2与藏红T直接反应,使藏红T的荧光猝灭,加入强碱弱酸盐对体系有增敏作用,据此提出了荧光法测定痕量NO-2的新方法。方法的线性范围为2.8～294ng/mL,方法的检出限为2.8ng/mL。可直接用于水样及蔬菜中痕量NO-2的测定。     

荧光猝灭法测定痕量NO2-

在HCl介质中,NO2-与5-氨基-1,2,3,4-四氢-1,4酞嗪二酮(ATPD)发生亚硝化反应,使ATPD的荧光猝灭,且其荧光猝灭程度与NO2-量呈线性关系,从而建立了测定痕量NO2-的新方法。该法线性范围为0.067~1.172μg/mL,方法检出限为0.70μg/L。本法已用于雨水中痕量NO2-的测定。     

荧光猝灭法测定壳聚糖含量

在pH 6.3的NaH2PO4-Na2HPO4缓冲溶液中,壳聚糖对荧光素的荧光强度具有明显的猝灭作用,且在一定浓度范围内,其猝灭程度与加入的壳聚糖浓度成线性关系,据此建立了一种新的测定壳聚糖含量的荧光猝灭分光光度法。该方法的回归方程为ΔF=64.02+42.28ρ(mg/L),R2=0.9942,线性范围为0.50~10.0 mg/L,检出限为0.27 mg/L。样品测定的RSD为4.5%(n=6),平均回收率为99.3%。采用该方法可测定复杂样品中的壳聚糖含量。     

荧光猝灭法测定次黄嘌呤及机理研究

研究了次黄嘌呤猝灭伊文思蓝的荧光猝灭机理并根据次黄嘌呤对伊文思蓝荧光的猝灭作用建立了测定次黄嘌呤的新方法.线性回归方程为:ρ=6.292×103F-1-26.49,相关系数为0.9990,线性范围为0.20～20.0 μg/mL,检出限为0.14 μg/mL,相对标准偏差(RSD)为2.5%.求算了伊文思蓝与次黄嘌呤的形成常数K=2.63×102L/moL,实验了pH、放置时间、干扰离子等对测定的影响.     

液膜分离富集二甲氧基羟基苯基荧光酮荧光猝灭法测定微量钼的研究

研究了在pH5．0～6．4的HAC-NaAC缓冲介质中和CTMAB存在下,Mo(Ⅳ)对二甲氧基羟基苯基荧光酮(DMH-PF)的荧光猝灭效应,建立了荧光猝灭法测定微量Mo(Ⅳ)的新体系,DMH-PF最大激发波长为λex=514nm、最大发射波长为λem=547nm,DMH-PF与Mo(Ⅵ）形成1：2配合物使荧光猝灭,荧光猝灭量与Mo(Ⅵ)在0～0．072mg／L范围内呈线性关系,方法的检出限为0．0022mg／L,体系稳定,灵敏度高,采用液膜分离富集钼,可应用于合金钢和石墨中微量钼的测定。     

Fluorescence resonance energy-transfer affects the determination of the affinity between ligand and proteins obtained by fluorescence quenching method

The interaction between esculin and serum albumins was investigated to illustrate that the fluorescence resonance energy-transfer (FRET) affects the determination of the binding constants obtained by fluorescence quenching method. The binding constants (K_a) obtained by the double-logarithm curve for esculin–BSA and esculin–HSA were 1.02 × 10⁷ and 2.07 × 10⁴ L/mol, respectively. These results from synchronous fluorescence showed that the Tyr and Trp residues of HSA were affected more deeply than those in BSA. The excitation profile of esculin showed that in the presence of BSA and HSA, the S₀ → S₁ transition of esculin () appears, which is similar to the of BSA and HSA. The critical distance (R₀) between BSA and esculin is higher than that of HSA, which showed that the affinity of esculin and HSA should be higher than that of BSA. After centrifugation, the concentrations of esculin bound to albumins were determined by means of the fluorescence of esculin. It was found that much more esculin was bound to HSA than to BSA. However, the bound models for BSA and HSA are almost the same. The concentration of esculin bound to serum albumin at first decreased with the addition of esculin and then increased. From above results, it can be concluded that the affinity of esculin and HSA should be higher than that of esculin and BSA. This example showed that in the presence of FRET, the binding constants between ligands and proteins based on fluorescence quenching might be deviated.     

Fluorescence quenching method for determination of trace tungsten in environmental samples with dibromohydroxyphenylfluorone

A highly sensitive and selective fluorescence quenching method has been developed for the determination of trace tungsten in environmental samples using dibromohydroxyphenylfluorone (DBHPF) as an emission reagent. In the presence of 0.04?mol/L of sulphuric acid and acetyltrimethylammonium bromide, tungsten(VI) reacts with DBHPF to form a 1?:?3 red complex within 5.0?min. In order for the DBHPF–tungsten(VI) complex to form, the fluorescence intensity of the reagent solution was quenched linearly by adding 0.1 to 1.0?µg of tungsten(VI) in 25?mL of solution. This was measured at 528?nm with excitation at 495?nm. In this work, a standard addition method was investigated and used for sample analysis. The decrease in fluorescence intensity of the reagent solution (ΔF) was linear for 0?～?0.9?µg of tungsten(VI) in 25?mL of solution, and the detection limit (3?s) of the standard addition method was found to be 0.012?ng/mL of tungsten(VI). The effects of various metal and nonmetal ions were studied in detail. The experiments clearly showed that most foreign ions can be tolerated in considerable amounts; in particular, 50-fold Mo(VI), V(V), Zr(VI) and Ti(IV) do not interfere, and the selectivity of the proposed method is better than other previously described methods. Moreover, the method proposed here is very stable and simple, the fluorescence intensity of the solution can remain almost unchanged for 2.0?h at room temperature, and the method has been used successfully to determine tungsten in environmental samples.     

亚甲基蓝荧光猝灭法测定抗坏血酸

在稀H2SO4介质中,抗坏血酸与亚甲基蓝发生反应,使其荧光猝灭,建立了荧光光度法测定痕量抗坏血酸的新方法,用正交法确定最佳测定条件。方法的激发波长为660 nm,发射波长为694 nm,在最佳条件下该法测定抗坏血酸的线性范围为0.1~40 mg/L,检出限为0.23 mg/L。方法可用于药品、饮料、果蔬中抗坏血酸的测定。     

CdSe/CdS量子点荧光猝灭法测定芹黄素的研究

以巯基乙酸为稳定剂,在水溶液中合成了具有特殊光学性质的水溶性CdSe/CdS量子点。以该量子点为荧光探针,基于荧光猝灭法对芹黄素进行了定量检测。考察了缓冲体系、反应时间、量子点浓度等多种因素的影响。实验结果表明,在0.001 mol/L、pH为6.80的KH2PO4-Na2HPO4缓冲液中,当量子点浓度为1.2×10^-4mol/L、反应时间为20 min时,该方法的线性范围为0.16-27.02μg/mL,其线性回归方程为F0/F=0.99665＋0.11067ρ（μg/mL）,相关系数r=0.998,检出限为0.13μg/mL,并用于合成样品的分析。     

CdTe量子点荧光猝灭法测定奥沙利铂中微量银

以谷胱甘肽作为稳定剂,100℃恒温回流,直接合成水溶性CdTe量子点。基于Ag+对合成的CdTe量子点的荧光猝灭效应,建立了测定抗癌药物奥沙利铂中微量银的方法。考察了量子点浓度、缓冲液种类、缓冲液浓度、缓冲液pH和反应时间对银离子测定的影响。当量子点浓度为0.004 g/L时,在0.10 mmol/LpH7.4的磷酸缓冲溶液中,反应时间为5 min,体系的相对荧光强度与Ag+的质量浓度呈良好的线性关系,其线性范围为16.42～98.50μg/L,线性相关系数为0.9975,检出限为0.12μg/L。     

Studies of interaction between colchicine and bovine serum albumin by fluorescence quenching method

We investigated the interaction between colchicine and bovine serum albumin (BSA) by fluorescence and UV–Vis absorption spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by colchicine is a result of the formation of colchicine–BSA complex; van der Waals interactions and hydrogen bonds play a major role in stabilizing the complex. The modified Stern–Volmer quenching constant K_a and corresponding thermodynamic parameters ΔH, ΔG, ΔS at different temperatures were calculated. The distance r between donor (BSA) and acceptor (colchicine) was obtained according to fluorescence resonance energy transfer (FRET).