胶束增敏荧光光度法测定土霉素的研究

提出了表面活性剂增敏的酸性降解荧光法测定土霉素的新方法。土霉素与浓H2SO4反应,生成强荧光降解物一脱水土霉素,在pH10.0的NH3 NH4Cl缓冲溶液中,CTMAB的存在对脱水土霉素的荧光有较强的增敏和增稳作用,土霉素含量在1.21×10-8mol/L～4.83×10-6mol/L范围内与荧光强度成正比,方法的检出限为6 66×10-9mol/L。应用本法测定片剂中的土霉素,平均回收率为99.6%(n=5)。     

荧光光度法测定环境水样中的苯酚和对苯二酚

建立了荧光光度法直接测定环境水样中的苯酚和对苯二酚的新方法.通过β-环糊精增敏,三维荧光扫描选择测量波长,在波长对为λex/λem=273/307 nm时测定苯酚,苯酚的线性范围为0～1×10-4 mol/L,检出限为6.6×10-8 mol/L;在波长对为λex/λem=295/331 nm时测定对苯二酚, 对苯二酚的线性范围为0～1.5×10-5 mol/L,检出限为5.2×10-9 mol/L,回收率达到93.5%～103.5%.     

流动注射化学发光法测定肉桂酸

碱性条件下,肉桂酸对Luminol-H2O2-纳米银化学发光体系有较强的增敏作用,据此,结合流动注射技术,建立了测定肉桂酸的新方法。该法线性范围为2.5×10-8～2.5×10-6mol/L,检出限为6.0×10-9mol/L,对1.0×10-7 mol/L的肉桂酸平行测定9次,相对标准偏差为2.5%。该法可用于尿液中肉桂酸的测定。     

蛋白质对溴鼠灵的荧光增敏及分析应用

实验发现, 牛血清白蛋白可以大大增强杀鼠剂溴鼠灵的荧光. 利用荧光猝灭法考察了溴鼠灵和牛血清白蛋白的相互作用. 结果表明溴鼠灵对牛血清白蛋白的内源荧光有较强的猝灭作用, 两者形成了新的复合物, 属于静态荧光猝灭. 跟据荧光增敏现象, 建立了水溶液中测定溴鼠灵的荧光方法. 在优化实验条件下, 线性范围为5.0×10-8～4.0×10-7 mol/L和4.0×10-7～1.5×10-5 mol/L, 检出限为5.9×10-9 mol/L. 该方法用于渠水中微量溴鼠灵的测定, 回收率为94.1%～101.3%.     

铕-速尿-TOPO荧光配合物的研究及速尿的测定

在pH7.8的缓冲溶液中,铕离子、速尿和三辛基氧膦(TOPO)反应生成稳定的三元配合物,该配合物溶解在Triton X-100胶束中。以280 nm光波激发,配合物发射出铕离子的特征荧光。分析了三元配合物的紫外及荧光光谱,对配合物的生成及TOPO和Triton X-100的荧光增敏机理进行了探讨。采用时间分辨荧光法测定配合物的荧光强度,其荧光强度和速尿的浓度在一定范围内呈线性关系,建立了工作曲线的线性回归方程。方法的检出限为6.6×10-8mol/L,测定精度RSD为1.3%(4.00×10-6mol/L,n=11)。用此方法测定尿液中痕量速尿,回收率为93.0%～103%。     

Fe3+-H2O2-二氯荧光素化学发光体系测定药物中的扑热息痛

酸性介质中,Fe3+催化H2O2分解生成羟基自由基,进而氧化扑热息痛产生微弱的化学发光,二氯荧光素对该发光强度有较强的增敏作用。研究了影响化学发光强度的各种因素,并探讨了其可能的发光机理。在最佳化学发光条件下,其化学发光强度与扑热息痛的浓度在8.0×10-8～5.0×10-5mol/L范围内呈良好的线性关系,检出限为5.0×10-9mol/L,对3.5×10-6mol/L的扑热息痛平行测定9次,其相对标准偏差为2.2%。该法用于片剂中扑热息痛含量的测定,结果满意。     

钇(Ⅲ)-莫西沙星配合物的荧光性质及分析应用

钇(Y3+)与莫西沙星(MoxifloxacinMXFX)形成的配合物能显著地增敏莫西沙星的荧光强度,据此,建立了测定莫西沙星的新方法。该方法的检出限为8.5×10-10mol/L;莫西沙星的浓度在1.0×10-8～1.0×10-6mol/L范围内与配合物体系的荧光强度呈良好的线性关系。对1.0×10-6mol/L莫西沙星平行测定12次,RSD为1.1%。该法可用于测定尿样中的莫西沙星。对荧光增强机理作了简要的探讨。     

巴洛沙星-Tb3+-ATP荧光体系的建立及其分析应用

在二元配合物巴洛沙星-Tb3+中加入ATP,Tb3+在其特征波长545 nm处的荧光强度增强,据此建立了新的巴洛沙星-Tb3+-ATP荧光体系.在最优化实验条件下,增强的荧光强度与ATP的浓度呈良好的线性关系,线性范围为2.0×10-6～3.0×10-5 mol/L,检出限为8.0×10-7 mol/L.详细的机理研究表明,ATP能与巴洛沙星-Tb3+形成大的三元络合物荧光体系.新建立的荧光体系成功地应用于ATP注射液中ATP的定量检测.对不同批次ATP注射液进行加标回收试验,回收率为101％～106％,测定结果的相对标准偏差为1.1％～1.9％(n=5).     

洛美沙星的铕离子荧光探针时间分辨荧光法测定

采用时间分辨荧光法,以铕离子为荧光探针,依据Eu3+-La3+-LMX-SDS稀土共发光体系,建立了测定洛美沙星(LMX)含量的新方法。研究了配合物的紫外及荧光光谱,分析了配合物的发光机理,考察了溶液pH值、缓冲溶液种类及反应试剂加入量对配合物荧光强度的影响。在优化的实验条件下,配合物荧光强度和洛美沙星浓度呈线性关系,相关系数为0.999 0,线性范围为5.0×10-7~1.0×10-5mol/L。方法的检出限为6.8×10-8mol/L,对5.0×10-6mol/L的洛美沙星溶液测定11次,RSD为0.6%。将该方法用于尿液中洛美沙星含量的测定,回收率为94%~104%。     

流动注射化学发光法测定中药材中没食子酸

建立快速简便的流动注射化学发光分析法,用于中药材中没食子酸含量的测定.利用酸性介质中Fe3+-H2O2体系生成羟基自由基氧化没食子酸产生微弱的化学发光,用罗丹明6G来增敏化学发光.研究了影响化学发光的各种因素,探讨了可能的机理.结果表明,0.18 mol/L HCl,0.04 mol/L FeCl3,1.0 mol/L H2O2与1.0×10-4 mol/L罗丹明6G溶液组成最优的化学发光体系,没食子酸浓度在1.0×10-5～1.0×10-2 g/L和0.01～1.0 g/L范围内与化学发光强度呈很好的线性关系,r分别为0.9984和0.9947,检出限为3.0×10-6 g/L.对1.0×10-4 g/L没食子酸平行测定11次的相对标准偏差为3.8%.利用本方法成功地测定了中药材诃子和没食子中的没食子酸含量.     

A new spectrofluorometric probe for the determination of trace amounts of CoA in injection, human serum and pig livers.

A new spectrofluorometric method has been developed for the determination of trace amounts of coenzyme A (CoA). Using europium (Eu3+)-tetracycline (TC) complex as a fluorescent probe in the buffer solution of pH 6.80, CoA could remarkably enhance the fluorescence intensity of the Eu3+-TC complex at lambda = 612 nm after adding H(5)IO(6) and the enhanced fluorescence intensity is in proportion to the concentration of CoA. Optimum conditions for the determination of CoA were also investigated. The dynamic range for the determination of CoA is 6.08 x 10(-8) - 1.84 x 10(-5) mol L(-1) with detection limit of 4.62 x 10(-8) mol L(-1). This method is simple, practical and relatively free of interference from coexisting substances and can be successfully applied to determination of CoA in injection, human serum and pig liver samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu3+-TC system and the CoA-Eu3+-TC system have been also discussed.     

表面活性剂对镧、钇-8-羟基喹啉-5-磺酸萤光反应的敏化作用

本文讨论了阳离子表面活性剂——溴化十六烷基三甲基铵(CTMAB)对萤光反应敏化作用的机理;提出了镧、钇的萤光分析方法,并确定了萤光反应的最佳条件。镧、钇的三元络合物与其二元络合物相比,萤光强度分别增强了四倍和十倍。表面活性剂的引入也大大地增加了方法的选择性。在此基础上,设计了先测定钇含量,然后用简单的作图法测定镧含量的镧、钇联合测定法。用本法测定了混合稀土样中谰、钇的含量,方法简便,结果令人满意。     

Development of selective,visible light-excitable,fluorescent magnesium ion probes with a novel fluorescence switching mechanism

Novel fluorescent Mg2+ probes, 2'-carboxyfluorescein (2'-CF) and its derivatives, that are excitable by visible light, were designed, synthesized and characterized. After complexation with Mg2+, the absorption and emission maxima of these fluorescent probes were red-shifted and the fluorescence intensity was increased 11-fold at neutral pH. The apparent dissociation constant (Kd) of the Mg2+-2'-CF complex was 15.8 mM at neutral pH. The Kd of the Ca2+-2'-CF complex was about 10 times larger than that of the Mg2+ complex and the other derivatives showed similar characteristics. In contrast, all the commercially available fluorescent Mg2+ probes have a higher affinity for Ca2+ than Mg2+. 2'-CF fluoresced in alkaline solution (pH > 8) and the pK, value was 8.8. The pKa value of the Mg2+-2'-CF complex was 6.8, and the fluorescence intensity was increased in the neutral conditions. Thus, the addition of Mg2+ resulted in a lowering of the pKa, and also an increase of the fluorescence intensity.     

Al(III)- CTMAB增敏酸性降解荧光法测定土霉素

The fluorescence characteristics of acid degraded product of oxytetracycline with aluminium(III) in micellar system has been studied.The experiment indicated that oxytetracycline reacts with hydrochloric acid and produces more strong fluorescent species.After CTMAB and aluminium(III)are added in this species,its fluorescence intensity can be enhanced greatly in pH 7.20 Na2HPO4-KH2PO4 buffer solution.Based on this,a new fluorimetric method involving acidic degradation and enhancement by surfactant and aluminium(III)is proposed for the determination of oxytetracyline.The maximum excitation and emission wavelengths are 392nm and 492nm,respectively.The fluorescence intensity is proportional to the concentration of oxytetracycline over the range of 2.01×10-8mol/L～2.10×10-6mol/L with the detection limit of 1.0×10-8 mol/L.The method has been used to the determination of oxytetracycline in tablets with satisfacoty results.     

Spectrofluorimetric determination of superoxide dismutase using a Europium-tetracycline probe

Superoxide dismutase (SOD) can enhance the characteristic fluorescence of europium in europium (Eu(3+))-tetracycline (TC) system. According to this, a new spectrofluorimetric determination of SOD was developed. Under the optimum conditions, Eu(3+)-TC formed a ternary complex in close proximity with SOD and then intra-molecular energy transfer from TC-SOD complex to Eu(3+), which resulted in the enhancement of characteristic peak of Eu(3+) at 612 nm. The enhanced fluorescence intensity is in proportion to the concentration of SOD, and the linear range was 0.0553-38.71 microg mL(-1) with the limit of detection of 5.53 ng mL(-1). The developed method was practical, simple, sensitive and relatively free from interference coexisting substances and has been successfully applied to the determination of SOD in the plant and blood samples. The mechanism of fluorescence enhancement between Eu(3+)-TC complex and SOD was also studied.     

表面活性剂对金属荧光反应的增敏作用

研究了各种类型的表面活性剂对铪-栎精、锆-栎精、锡-桑色素、镁-8-羟基喹啉-5-磺酸(镁-H_QS)、锌-H_2QS、镉-H_2QS、铽-EDTA-磺基水杨酸体系荧光光谱的影响.结果表明:在适当的表面活性剂存在下,各种配合物的荧光强度均大大增强.确定了在有表面活性剂参与下三元配合物的最佳形成条件;以荧光法测定了这些荧光配合物的组成.用相对法测定了有表面活性剂和没有表面活性剂存在时荧光配合物的量子效率,并计算了在激发波长下各自的摩尔吸光系数.发现在有表面活性剂存在时,由于生成了有固定组成的三元离子缔合物,荧光配合物的量子效率和摩尔吸光系数都有不同程度的提高,从而大大增强了它们的荧光强度.讨论了表面活性剂胶束的作用以及表面活性剂的分子结构对荧光反应的影响.指出只有那些分子中带电荷基团与共轭大π键不相邻的表面活性剂才能对荧光反应起增敏作用.利用表面活性剂的增敏作用有可能建立一些高灵敏度的金属荧光分析法.     

罗丹明类荧光探针的合成及对铜离子的检测

合成了罗丹明类Cu2+荧光增强型分子探针3',6'-双(二乙氨基)-2-(N-乙叉基氨基)螺[异吲哚-1,9'-占吨]-3-酮（RA）,并研究了它的光谱性能及对铜离子的识别作用.在乙腈/水（体积比1/1）的介质中,当加入Cu2+后探针RA显玫瑰红色,最大吸收波长为548 nm,最大发射波长为571 nm,且荧光强度显著增强,但是,其它常见离子如Na+, K+, Mg2+, Ca2+, Mn2+, Cd2+, Cr3+, Co2+, Ni2+, Ag+, Pb2+, Zn2+, Fe3+, Hg2+不引起或引起很小的紫外/可见或荧光光谱变化.RA的选择性荧光增强主要是由于Cu2+诱导分子中的酰胺闭环结构发生开环,导致分子结构的共轭程度增大.在6.5×10-8～2.9×10-6 mol?L-1范围内RA可以有效检测Cu2+,检测限为5.0×10-8 mol?L-1.RA对Cu2+的识别不可逆,而且探针RA对pH值不敏感,可以在比较宽的范围内（pH=4.1～10.5）高灵敏、高选择性检测Cu2+.     

碘化钾-十六烷基三甲基溴化铵-水体系液固分离银的研究

本文利用碘化钾-十六烷基三甲基溴化铵-水微晶吸附体系研究了银离子的液固分离行为.分别考察了KI用量、CTMAB用量、溶液酸度、盐和放置时间对分离效率的影响,结果表明,当2％碘化钾溶液溶液和2.0×10-3 mol·L-1 CTMAB溶液的用量均为1.0 mL时,Ag+、I-、CTMAB+形成的三元缔合物AgI2-·CT...     

Investigation on hyperin-cetyltrimethylammonium bromide-fibronectin system by resonance light-scattering technique

A simple, highly sensitive assay for fibronectin (Fn) was reported using resonance light-scattering (RLS) technique based on the enhanced RLS intensity of hyperin-cetyltrimethylammonium bromide (CTMAB)-Fn system. The interaction system of hyperin-CTMAB-Fn was investigated using spectral methods. Mechanistic investigations show that the main reason of the enhanced RLS intensity of Fn is the formation of three-component complex (hyperin-CTMAB-Fn), in which CTMAB acts as a bridge between hyperin and Fn. The effects of pH, surfactant, concentration of CTMAB and hyperin, incubation time and foreign substances on the enhancement of RLS intensity were studied. Under the optimum conditions, the enhancement of RLS intensity is in proportion to the concentration of Fn in the range of 1.9-248ng/ml. The synthetic samples containing Fn were analyzed and results obtained were satisfied.     

A tryptophan-containing open-chain framework for tuning a high selectivity for Ca2+ and 13C NMR observation of a Ca2+-indole interaction in aqueous solution

Two molecular architectures featuring the cation-responsive tryptophan indole were designed and investigated for the development of a novel fluorescent chemosensor for Ca2+. We observed that the Trp-based open-framework chemosensor EW2 exhibits remarkable selectivity for Ca2+ over Mg2+, Ba2+, K+, Na+, and Li+ in water between pH 4.6 and 7.0 on the basis of Ca2+-induced high fluorescence enhancement of the Trp residue. A combined 13C NMR and CD spectroscopic study has demonstrated a dynamic reorientation of the indole ring due to the cation-indole interaction accompanying the Ca2+-induced dramatic fluorescence enhancement. The results suggest that the highly sensitive, metal-ion-dependent Trp indolyl C(3) chemical shifts may serve as a promising indicator for monitoring metal ion-indole noncovalent interaction in solution.