首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 593 毫秒
1.
将阳离子表面活性剂、非离子表面活性剂和阴阳离子表面活性剂应用于铝(Al)-铬天青S(CAS)体系以测定微量铝,已有不少报导,对提高反应的灵敏度,改善反应条件取得了良好的效果,有的体系已用于钢铁中微量铝的测定。我们曾把两性表面活性剂用于稀士元素的分析,表现出灵敏度高,选择性强,水溶性、稳定性好等优点。本文试图把两性表面活性剂应用于Al-CAS体系,研究其分光光度性质和反应机理,并寻求一个高灵敏度测定微量铝的新方法。试验证明,两性表面活性剂:N-十二烷基二甲基铵基乙酸(DDMAA),N-十二烷基二聚氧乙烯铵基乙酸(DDPAA)均能与铝、铬天青S形成三元胶束络合物,并表现出突出  相似文献   

2.
使胶束增溶分光光度法在保持已有灵敏度的基础上,再提高其显色反应的选择性,是一个既有理论意义又有应用价值的新课题.作者在研究两性表面活性剂的分析应用时发现,如在其显色体系中同时引入非离子表面活性剂Triton X-100,则对体系的光化学性质有明显影响,有的灵敏度提高,有的选择性改善.实验表明,两性-非离子混合型表面活性剂的存在,可以扩大不同显色体系的差别,对提高增溶光度法的灵敏度,特别是选择性,是一种有效的途径.基于此,作者曾在钪、铀、钍等元素的分析测定方面作过一些研究. 本文以金属-铬天青S(CAS)-烷基二甲基乙酸铵两性表面活性剂的显色反应为例,研究非离子表面活性剂Triton X-100在体系中的作用;以及两性表面活性剂与大过量Triton X-100共存,提高CAS显色反应选择性的可能性;并对其作用机理进行初步探讨.  相似文献   

3.
文献报导了基于利用非离子表面活性剂胶束增溶离子对缔合物所建立的水相测磷、砷和锗的分光光度法,为发展此类高灵敏度的显色反应和扩大非离子表面活性剂在光度分析中的应用提供了新的途径。本文研究在乳化剂OP存在下,孔雀绿-磷钼杂多酸缔合物分光光度法测定微量磷。为非离子表面活性剂对离子对缔合物的增溶作用又提供了一例。  相似文献   

4.
正负离子表面活性剂与两性表面活性剂的相互作用   总被引:3,自引:0,他引:3  
本文研究正负离子表面活性剂与两性表面活性剂混合水溶液的表面性质, 以及两性表面活性剂对正负离子裘面活性剂溶解度的影响。结果表明: (1) 两性表面活性剂的加溶作用,有助于正负离子表面活性剂的溶解; (2) 加入两性表面活性剂的量适当, 混合溶液基本保持原正负离子表面活性剂的表面活性; (3) 正负离子表面活性剂与两性表面活性剂在表面层和胶团中分子间的相互作用比正负离子表面活性剂与非离子表面活性剂分子间的相互作用稍强HC-FC正负; 离子表面活性剂与两性表面活性剂混合体系在表面层中有可能形成双分子或多分子层结构。  相似文献   

5.
离子型-非离子型混合表面活性剂对显色反应能产生协同增敏作用,我们曾应用Ag~+-5-Cl-PADAB-SDS-Peregal O体系测定Ag~+和CN~-,获得了满意的结果。本文以Cd-1-(2-吡啶偶氮)间苯二酚(PAR)-CTMAB-非离子表面活性剂和Al-CAS-CTMAB Peregal O体系为例,进一步研究了阳离子-非离子混合表面活性剂对显色体系的作用特征和规律,以期待有助于发展高灵敏、高选择性的分光光度法。  相似文献   

6.
——本文研究在Be~(2+)、Cu~(2+)和Al~(3+)的铬天青S(CAS)络合物可见光度法中,表面活性剂一诱导变色的机理。在阳离子表面活性剂(溴化十六烷基三甲铵、CTAB)存在下,对所有三种金属络合物,均观察到摩尔吸光系数的增加和最大吸收波长的红移。在非离子表面活性剂(TritonX-100,即TX-100)存在下,对Be~(2+)及Cu~(2+)的络合物,也观察到相同情况。在高离子强度时,发现阴离子表面活性剂(十二烷基硫酸钠,SDS)有类似的效应。在使用TX-100和SDS时,只涉及到严格意义下的胶束相互作用。而在使用CTAB时,既观察到包括表面活性剂单体在內的三元络合物的形成,也观察到了胶束相互作用,即在低浓度CTAB时,形成具有明确组成的络合物;到临界胶束浓度以上时,则为胶束相互作用。所有“表面活性剂增敏”体系的光谱都很类似,意味着生色团在三元络合物中和在胶束中有类似的微环境。  相似文献   

7.
本文用分光光度和核磁共振两种实验方法研究非离子表面活性剂(记作n-Sf)胶束对漂蓝6B(ECAB)及其金属络合物的增溶增敏作用。n-Sf对金属络合物的增溶增敏作用发生在胶束的极性部分与非极性部分的交界处,故n-Sf分子中的烷基链与聚氧乙烯链是否直接相联,会影响到金属-ECAB络合物的吸收光谱形状、λ_(max)和ε值。n-Sf胶束增溶ECAB,会抑制ECAB的酸式离解。  相似文献   

8.
近年来非离子表面活性剂应用于光度分析日益增多,但其胶束增溶显色反应机理的研究,还很少报导。 本文以分光光度法研究了Ni~(2 )-1-(2-吡啶偶氮)-2-萘酚(PAN)-TritonX-100体系,并与溶剂萃取法进行了比较;同时结合体系的浊点试验、PAN在聚乙二醇和乙醇溶液中的光谱特性等结果,对聚氧乙烯型非离子表面活性剂胶束增溶显色反应的机理,进行了初步讨论。  相似文献   

9.
用聚合表面活性剂作增敏试剂分光光度测定钼和钨   总被引:2,自引:0,他引:2  
刘昆元  俞汝勤 《化学学报》1987,45(6):584-589
采用表面活性剂的分光光度分析法应用日趋广泛。这方面的研究工作虽极活跃,但较多工作限于已有经典表面活性剂的研究与应用,为分析化学的特定需要设计与合成新型表面活性剂的研究尚少。作者曾用环氧氯丙烷和长链烷基叔胺合成了以聚乙二醇为主链含有若干个带长链烷基的季氮支链的低聚合表面活性剂——聚(氧化丙烯)-α-十八烷基二甲基氯化铵(PPOSA)。实验表明,这类表面活性剂兼有阳离子和非离子表面活性剂的某些特性。本文  相似文献   

10.
近年来应用表面活性剂,提高铬天青S(CAS)光度法测定铍的灵敏度的报道日益增多,但多数是应用阳离子表面活性剂作增感剂。本文应用非离子表面活性剂-聚乙二醇辛基苯基醚(乳化剂OP),在溶液pH4.0~6.0的条件下,铍与CAS及OP生成三元络合物,最大吸收峰在620毫微米处,摩尔吸收系数ε=8.75×10~4。采用EDTA作掩蔽剂消除干扰离子的影响。本法可不经分离直接用于矿石中微量铍的测定,结果良好。  相似文献   

11.
The chelation reactions of Sc3+, Y3+, and some lanthanides with Eriochrome azurol B in the presence and absence of cetyltrimethylammonium bromide has been studied in detail. The complexes show a marked bathochromic shift in their λmax at pH 6.0. The composition of the complexes in the absence and presence of cetyltrimethylammonium bromide was found to be 1:2 (Metal:ligand). The values of the conditional formation constants have also been evaluated. The studies were further extended to the analytical aspects of the complex equilibria and a suitable procedure has been recommended for the spectrophotometric microdetermiantion of Sc3+, Y3+, and some lanthanides under study using Eriochrome azurol B in the presence of cetyltrimethylammonium bromide which considerably increases the sensitivity of the color reaction. The use of Eriochrome azurol B in the presence of cetyltrimethylammonium bromide as a complexometric indicator has also been reported.The effect of surfactant concentration and the effect of mineral salts on the absorption spectra of Eriochrome azurol B at pH 11.6 and 6.0 have also been reported.  相似文献   

12.
The interaction of Cr(III) with Chrome azurol S (CAS) in water–glycerol binary mixtures has been investigated by spectrophotometry. The absorption electronic spectra of Chrome azurol S and its complex with Cr(III) in water–glycerol media with glycerol contents from 10 to 50% by vol. have been measured. The stability constant of the complex in water–glycerol binary mixtures has been determined. It has been shown that the rate of reaction increases as the organic solvent content increases.  相似文献   

13.
蛋白质与铁(Ⅲ)-铬天青S结合反应的研究   总被引:7,自引:0,他引:7  
蛋白质与铁(Ⅲ)-铬天青S结合反应的研究魏永巨,李克安,童沈阳(北京大学化学系,北京,100871)关键词血清白蛋白;γ-球蛋白;铁(Ⅲ)-铬天青S配合物;吸收光谱某些金属配合物与蛋白质的结合反应已被用于蛋白质的定量分析[1~4]。我们用吸收光谱法研...  相似文献   

14.
A comprehensive investigation of the spcctrophotometric determination of aluminium with chrome azurol S is described. No heating is required for colour formation, and the method is considerably more reproducible and selective than either the eriochrome cyanine R or aluminon methods. In the presence of suitable masking agents, only Be2+, Zr4+, and F-cause serious interference. A molar absorptivity of 21,500 at 567.5 mμ was found for the aluminium-chrome azurol S lake, with a relative standard deviation of ± 0.4% at the 20 μg Al level. Beer's law is obeyed from 0 to 1.2 mg Al/ml.  相似文献   

15.
一阶导数光谱法测定指示剂类多元酸离解常数   总被引:2,自引:0,他引:2  
张淑芳  秦梅 《分析化学》1998,26(8):931-934
研究了铬天青S在不同PH缓冲溶液中的吸收光谱及一阶导数光谱,并据此拟定出一个测定各有离解常数的方法,推导出计算公式。测定方法简单,结果与文献值比较令人满意。  相似文献   

16.
An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(III) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(III):chrome azurol S: cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×104 L·mol?1-cm?1 and a linear range of 0.1–6.0 μmol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.  相似文献   

17.
A simple and sensitive method for assay of human serum albumin (5–80 μg) is based on binding of chrome azurol S by the albumin and determination of the bound dye spectrofluorimetrically. The method is sufficiently sensitive for application to spinal fluid (20–100 μl).  相似文献   

18.
《Analytical letters》2012,45(12):2289-2304
Abstract

A flow injection analysis system which employs a visible absorption detector is used for the determination of beryllium. Be(II) ions are detected by means of a complexation reaction between Be(II) and chrome azurol s as the chomogenic reagent. The reaction forms a stable 1:1 complex which appears dark red-violet. The optimum conditions for the determination are pH 4.15, 35% chrome azurol s, 3% buffer, 62% HCI and 1,3-phenylenediamine, flow rate of 1.0 mL/min, and wavelength at 570 nm. A concentration limit of 0.1 μg/mL (or 2 ng in 25 μ of a sample injected) of Be(II) can be detected, and the linear dynamic range extends to 100 μg/mL. Some interference limits are established in the presence of EDTA and thiosulfate which are used as masking agents.  相似文献   

19.
海洋细菌中铁载体的分离纯化和活性研究   总被引:1,自引:0,他引:1  
游美羡  张惠平  胡昌奇 《中国化学》2008,26(7):1332-1334
从海洋来源的细菌发酵液中分离得到三个铁载体,其中化合物3为新化合物,化合物1和2为已知化合物nocardamine和schizokinen A。 通过CAS液体检测的方法测定了三个化合物的最低活性浓度,分别为:5, 4 及156μg/mL。  相似文献   

20.
Optimum conditions for the formation of ternary complexes of scandium, ytrium and lanthanum ions with chrome azurol S, eriochrome cyanine R and pyrocatechol violet in the presence of cetyltrimethylammonium, cetypyridinium and tetradecyldimethylbenzyl-ammonium (zephiramine) ions are described. The spectrophotometric determination of scandium with chrome azurol S and zephiramine exhibits the greatest sensitivity (? = 1.50 × 105 l mol?1 cm?1 at 610 nm). In the spectrophotometric determination of scandium with eriochrome cyanine R and cetylpyridinium ion (? = 9.2 × 104 at 600 nm), the interference caused by yttrium is the least. In the best method for yttrium (with pyrocatechol violet and zephiramine), the molar absorptivity is 3.3 × 104 at 660 nm. Lanthanum does not form ternary complexes of analytical interest in these systems. Some aspects of the formation of ternary complexes with cationic surfactants are discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号