红霉素与水杨基荧光酮胶束增敏荷移反应光度分析

本文提出了一种基于胶束增敏荷移反应测定红霉素的光度分析法.研究了在阴离子表面活性剂十二烷基硫酸钠(SDS)胶束体系中红霉素作为电荷供体与电荷受体水杨基荧光酮(SAF)之间的荷移络合物的光谱性质.发现SDS对该体系有增敏作用(ε=3.95×104 L·mol-1·cm-1提高近3倍),红霉素浓度在0.73mg/L～51.4mg/L范围内符合比尔定律,r=0.9999.本方法用于片剂中红霉素含量的测定,回收率为99.7%,9次测定的相对标准偏差为0.24%.     

阳离子表面活性剂与茜素红的荧光反应及其分析应用

应用荧光光谱法研究了3种阳离子表面活性剂(CS)与茜素红(Alizarin red,AR)间的相互作用.在pH 6.60的Britton-Robinson(B-R)缓冲溶液中,当CS的浓度较低时,CS的加入使AR的荧光猝灭,而高浓度时却使荧光增强.因此认为低浓度时CS单体与AR形成稳定离子缔合物使体系荧光猝灭,而高浓度时则形成胶束抑制缔合物的形成而表现出胶束的增溶增敏特性.在0.1～30.0 mg/L的质量浓度范围内荧光强度变化与CS浓度呈良好的线性关系,检出限分别为0.018 mg/L(十六烷基三甲基溴化铵,CTMAB)、0.025mg/L(氯化十六烷基吡啶,CPC)和0.032 mg/L(氯化十四烷基二甲基苄铵,Zeph).该方法用于水样中CS含量的测定,回收率为99%～103%.     

三聚氰胺的共振散射光谱分析

在pH 3.8的醋酸盐缓冲溶液中,三聚氰胺（MA）可与阴离子表面活性剂十二烷基苯基磺酸钠（SDBS）形成稳定的缔合物微粒.该缔合物微粒体系在472 nm处存在较强的共振散射峰.三聚氰胺浓度在1.0-23.3 mg/L范围内与472 nm处共振散射光强度成线性,检出限为32μg/L MA.研究了共存物质对SDBS共振散射测定三聚氰胺的影响,方法的选择性比较好,应用于合成废水测定,结果满意.     

乙基紫-阴离子表面活性剂体系的共振瑞利散射光谱及其分析应用

在弱酸性介质中,乙基紫(EV)与阴离子表面活性剂(ASF)反应形成离子缔合物,导致共振瑞利散射增强,并产生新的RRS光谱,最大RRS峰位于330nm和508nm。方法有很高的灵敏度,对于ASF的检出限分别为1．1μg／L十二烷基苯磺酸钠(SDBS)、2．5μg/L十二烷基硫酸钠(SDS)和270mg／L十二烷基磺酸钠(SLS),可用于痕量ASF的测定。研究了离子缔合反应的适宜条件,讨论了离子强度、有机溶剂、温度的影响,考察了方法的线性范围和选择性。方法用于合成水样和环境水样中阴离子表面活性剂的测定,获得了满意结果。     

维多利亚蓝B-双波长分光光度法测定垃圾渗滤液中十二烷基磺酸钠

在pH 7.3的B-R缓冲溶液中,阴离子表面活性剂十二烷基磺酸钠(SDS)与维多利亚蓝B(VBB)以物质的量比2:1反应生成具有正吸收和负吸收的蓝色离子缔合物,最大正吸收波长为690 nm,最大负吸收波长为615 nm,线性范围分别为0.2～8.2 mg·L-1(正吸收)和0.2～6.8 mg·L-1(负吸收),表观摩尔吸光率为3.48×104L·mol-1·cm-1(正吸收)和2.14×104L·mol-1·cm-1(负吸收),采用双波长叠加测定,灵敏度可达5.60×104L·mol-1·cm-1,据此建立了测定SDS含量的双波长分光光度法.探讨了适宜的反应条件及垃圾渗滤液的预处理方法.该法用于垃圾渗滤液中SDS含量的测定,回收率在98.5 0A～101.0H之间,测定值的相对标准偏差(n=5)在0.8%～1.5%之间.     

Cu(Ⅰ)-2,2′-联喹林-荧光素三元缔合配合物萃取光度性质研究

对Cu(I)-2,2′-联喹林与四嗅四碘、四氯四碘荧光素所形成的三元缔合配合物的萃取光度性质进行了较全面的研究.因离子对的等色性、缔合物的增敏效应以及向氯仿萃取液中加入乙醇或丙酮的增敏作用,大大提高了测定的灵敏度(ε>1×10~5).萃取体系又因保留了Cu(Ⅰ)专属试剂的整合反应,从而具备良好的选择性.     

Cu（Ⅰ）—2,2‘—联喹林—荧光素三元缔合配合物萃取光度性质研究

对Ｃｕ（Ⅰ）－２,２’－联喹啉与四溴四磺、上氯四碘荧光素所形成的三元缔合配合物的萃取光度性质进行了较全面的研究,因离子对的等色性、缔合物的增敏效应以及向氯仿萃取液中加入乙醇或丙的增敏作用,大大提高了测定的灵敏度。萃取体系又因保留了Ｃｕ（Ⅰ）专属试剂的螯合反应,从而具备良好的选择性。     

Cu(Ⅱ)-头孢羟氨苄的荧光光谱性质及应用

采用不同的表面活性剂对Cu(Ⅱ)与头孢羟氨苄生成的配合物在胶束体系中的荧光性质进行了研究,发现在pH6.2的Tris缓冲溶液中阴离子表面活性剂十二烷基硫酸钠对其配合物的荧光有显著的增敏作用,据此建立了胶束增敏荧光光谱法测定头孢羟氨苄的新方法。在最佳实验条件下其线性范围为0.03~1.14μg/mL,检出限为0.03μg/mL,经实际样品测定,其平均回收率为97.3%~101.4%,相对标准偏差为1.1%~1.3%。     

胶束增稳荷移反应紫外分光光度法测定洛美沙星

提出了一种基于胶束增稳荷移反应测定洛美沙星的紫外分光光光度法 ,研究了在阳离子表面活性剂溴化十六烷基吡啶 (CPB)胶束体系中电子给体洛美沙星与电子受体四氯对苯醌之间的荷移反应产物的紫外光谱性质。发现CPB对洛美沙星与四氯对苯醌的荷移反应络合物有显著的增稳效应。洛美沙星的浓度在0 .8～ 5 4mg L范围内符合比尔定律 ,r =0 .9994。在测定波长 32 3nm处 ,络合物的表观摩尔吸光系数为 3.5 6×10 - 4L·mol- 1 ·cm- 1 。本方法用于片剂中洛美沙星含量的测定 ,其回收率为 97.8%～ 10 0 .5 % ,相对标准偏差为0 .9%～ 2 .4 %。     

胶束在线扫集毛细管电泳法测定三聚氰胺

研究胶束在线扫集毛细管电泳法测定三聚氰胺的可行性,结果表明,与区带毛细管电泳相比,胶束在线扫集毛细管电泳法富集倍数提高约60倍。缓冲体系为140 mmol/L SDS+20 mmol/L NaH2PO4(pH 2.20)+10%(体积分数)甲醇,分离电压-18 kV,进样时间30 s,测量波长214 nm。考察了SDS浓度、pH、进样时间、运行电压等因素对分离测定的影响情况。在优化条件下,三聚氰胺在9 min时出峰,峰面积RSD≤3.7%。方法检出限、线性范围、相关系数分别为:0.13μg/mL、0.50~32.0μg/mL、0.9997。方法可用于奶粉中三聚氰胺的分离测定。     

茜素红S-硼酸体系对单糖的双光谱识别

利用硼酸与茜素红S和糖中的邻二羟基可逆结合的特点,以硼酸为中介运用竞争结合作用机理构建单糖分析法.在pH7.4的KH2PO4-NaOH缓冲溶液中,茜素红S作为指示剂与硼酸结合生成ARS-BA配合物,其结合常数为5.09×102L/mol.糖与指示剂ARS竞争结合硼酸使指示剂游离出来,产生明显的颜色变化,据此建立糖的识别方法.考察了D-葡萄糖、D-山梨醇、D-半乳糖、D-甘露糖、D-果糖、D-阿拉伯糖和L-阿拉伯糖对上述ARS-BA体系光谱的影响.结果显示:该体系对D-山梨醇和D-果糖有较好的光谱响应,其光谱变化灵敏度依D-山梨醇＞D-果糖＞D-阿拉伯糖～D-半乳糖＞D-葡萄糖＞D-甘露糖＞L-阿拉伯糖之序.     

茜素红 S与蛋白质的反应机理研究

应用UV光谱法研究在pH4.35的缓冲溶液中, 茜素红 S(ARS)与牛血清蛋白(BSA)间的相互结合反应。测定了平均结合数n=8, 分配结合常数K~c=1.5×10^5。研究了小分子探针与蛋白质的反应机理, 相互间的结合部位及结合力。该复合物结合前后的等吸收波长红移28nm, 这是目前此类结合反应研究中, 其分子间结合力较大的一例。进一步研究了ARS与多种蛋白质的结合反应, 以及离子强度对该体系的影响。提出了合适的反应模型。     

茜素红可见分光光度法测氯霉素的含量

研究了氯霉素与茜素红之间的络合反应,确定了最佳反应条件,建立了一种快速、简便测定氯霉素含量的可见分光光度法。研究表明,在pH=11.41的B-R介质中,氯霉素与茜素红在室温条件下即可形成1∶1型络合物,该络合物的λmax=474 nm,表观摩尔吸光系数ε为1.19×104L/(mol.cm)。氯霉素的浓度在2.0×10-7～3.0×10-5mol/L范围内服从比耳定律,相关系数r为0.9985。测定结果的相对标准偏差为0.86%(n=10),回收率为99.4%～101.2%。     

茜素紫分光光度法测定锌合金中的微量锡

在酸度0.15N、波长570nm处,消除干扰元素的情况下,利用葛素紫与锡形成稳定紫红色赘合物,用分光光度计测定锌合金中的微量锡。经比对实验证明,该方法准确可靠。     

Spectrophotometric determination of zirconium with alizarin red S in the presence of polyvinylpyrrolidone

The absorbance of the microcolloidal zirconium/alizarin red S/polyvinylpyrrolidone complex is measured at 525 nm in acetate buffered medium at pH 4.75. The molar absorptivity is 3.8 × 10⁴ l mol^?1 cm^?1, which is much greater than that of the classical method. Sulphate and fluoride do not interfere.     

茜素红荷移光度法测定阿魏酸哌嗪

研究了茜素红与阿魏酸哌嗪的显色反应,建立了阿魏酸哌嗪含量测定的分光光度法.在水溶剂中阿魏酸哌嗪与茜素红发生荷移反应生成紫红色的复合物,其最大吸收波长为524nm,表观摩尔吸光系数为1.86×103 L·mol-1·cm-1.阿魏酸哌嗪的浓度在1.60⁴8.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%48.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%¹00.9%之间.     

Flow-injection spectrophotometric determination of fluoride by using the zirconium/alizarin red S complex

A spectrophotometric flow-injection procedure is described for fluoride in aqueous samples. The method is based on the decrease in absorbance of the zirconium/alizarin red S complex at 520 nm; linear response is obtained for the range 0.1–10 mg l^?1 fluoride at a sampling rate of 100 h^?1. Aluminum(III), iron(III) and phosphate interfere.     

A voltammetric method for fluoride

A voltammetric method for the determination of micro amounts of fluoride is described. It is based on the measurement of the amount of free alizarin red S liberated by the fluoride ion from a zirconium-alizarin red S complex. The free dye measurement carried out at 0.7 V vs. S.C.E. depends on the anodic reaction of alizarin red S at the rotating pyrolytic graphite electrode. The method is simple, sensitive and suffers from relatively few interferences.     

Dynamic interaction between melamine and cyanuric acid in artificial urine investigated by quartz crystal microbalance

The dynamic interaction between melamine (M) and cyanuric acid (CA) in artificial urine was investigated by a flow injection analysis-quartz crystal microbalance (FIA-QCM) system. Melamine was used as the recognition element and immobilized onto the QCM gold surface. The process of M and CA interaction was recorded by FIA-QCM in real-time. The multilayer complex of M and CA was successfully formed on the crystal surface of the QCM when CA and M were introduced into the FIA-QCM system alternately. The influence of pH on the M and CA interaction indicated that the M-CA multilayer complex possesses high stability over a wide range of pH values, especially in physiological urine condition. The association and dissociation rate constants were determined under artificial urine condition and the association constant for M and CA was calculated as 10(2) L mol(-1). The M-CA complex was further characterized by Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM). Mechanism study suggested that the formation of the multilayer complex in artificial urine was mainly attributed to the intermolecular hydrogen bonding between M and CA. The work provides direct insight into the dynamic interaction between M and CA under physiological conditions and would be helpful for the research of kidney stones induced by melamine contamination.     

Site-selective probe for investigating the asynchronous unfolding of domains in bovine serum albumin

A convenient method is proposed for precise investigation of the asynchronous structural transition of the domains in bovine serum albumin (BSA) during unfolding process. The method is based on a site-selective probe, alizarin red S (ARS), which has a high affinity to the subdomain IIA of BSA. BSA-ARS complex was formed and gradually unfolded by urea from 0 to 8.0 M. The unfolding occurred in different domains of BSA resulted in distinct alterations of the microenvironment of the bound ARS. The spectral response of BSA-ARS complex, including the color, the UV absorption at 530 and 432 nm, and the intrinsic fluorescence at 342 and 310 nm with the excitation wavelength of 280 nm, showed slight changes in the urea concentration from 0 to 4.5 M, drastic changes from 4.5 to 6.0 M, and almost no changes from 6.0 to 8.0 M. The redox behavior of bound ARS between 0.3 and 0.8 V also showed the same trend. Consequently, a two-step, three-state transition process was monitored by naked eyes, UV-vis spectroscopy and electrochemistry. It is the first report to realize the indicator of the intermediate state during the unfolding process of BSA through convenient methods instead of expensive approaches. The work provides a facile method for the investigation of the unfolding process of multidomain proteins.