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1.
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   

2.
多元络合物中混合胶束的形成及其分析应用——Fe-CAS体系   总被引:2,自引:2,他引:2  
近年来,不同类型的表面活性剂在分析化学中得到广泛应用,显示出较好的优越性。尤其混合表面活性剂的应用,虽然研究工作不多,却呈现出较大的特点。其反应不但灵敏度高,选择性好,而且反应条件宽容,体系稳定。目前已用于Sc、U、Pb、Pd的测定中,取得了较好的效果。本文把两性-非离子混合表面活性剂应用于Fe-CAS体系,研究其光化学性质及形成条件,以期寻求高灵敏度、高选择性测定铁的新方法。实验结果表明,混合表面活性剂比单纯两性、非离子表面活性剂应用于Fe-CAS体系灵敏度高,选择性好,使原来与CAS显色的元素:Zr、Ti、Ga、In、Cu、RE、Ni、Co等均不干扰;体系稳定,能允许  相似文献   

3.
表面活性剂对Me-5-Br-DEPAP及Me-5-Cl-PADAB显色反应作用的研究   总被引:1,自引:0,他引:1  
我们曾研究了离子型-非离子型混合表面活性剂对Ag2+-5-Cl-PADAB和Cu2+-5-Cl-PADAB等显色反应的作用。本文研究了阴离子、阳离子、非离子及阴-非混合表面活性剂对一系列Me-5-Br-DEPAP及Me-5-Cl-PADAB显色反应的作用,试图寻求表面活性剂对显色体系增敏作用及协同增敏作用的原因,并对其作用机理作一初步探讨。  相似文献   

4.
我们曾研究了离子型-非离子型混合表面活性剂对显色反应的作用.本文通过测定显色剂在表面活性剂胶束相和水相中的分配系数,考察了分配系数和显色反应灵敏度的关系,进一步探讨了阳离子型-非离子型混合表面活性剂对显色反应协同增敏作用的机理. 根据析相模型,显色剂(配位体)在胶束相和水相中的分配系数可表示如下:  相似文献   

5.
王瑜  曹以诚  韩玉淳 《化学通报》2011,(11):982-982
本文以构建有效的非病毒基因载体为目的,研究了C12C6C12Br2/C12E10混合表面活性剂组成对其与DNA之间相互作用的影响,并对混合表面活性剂与DNA形成的聚集体结构和形貌进行了表征。结果表明,当固定混合表面活性剂的总浓度为1.0 mmol/L时,混合表面活性剂组成的改变会引起混合体系浊度、聚集体表面电荷和聚集体...  相似文献   

6.
本文研究了在SDBS和TPB阴阳离子混合表面活性剂存在下镧与偶氮硝羧的显色反应,两种表面活性利在等摩尔附近时具有显著的增敏作用,其ε_(730)为3.00×10~5l,mol~(-1),cm~(-1),用电导法测定了混合表面活性剂的临界胶束浓度。  相似文献   

7.
荧光分析中应用表面活性剂的报导不多,但已可看出,加入适宜的表面活性剂可提高方法的灵敏度和选择性。为研究阳离子表面活性剂的增敏作用,我们选择了钪-8-羟基喹啉-5-磺酸-溴化十六烷基三甲铵(CTMAB)体系进行了试验,确定了三元络合物的组成,拟定了混合稀土中微量钪的测定方法。灵敏度达5×10~(-8)M,这在测定钪的荧光方法中是比较高的。  相似文献   

8.
王腾芳  尚亚卓  彭昌军  刘洪来 《化学学报》2009,67(11):1159-1165
研究了离子液体型表面活性剂C12mimBr与阳离子表面活性剂Gemini 12-3-12, DTAB及阴离子表面活性剂SDS复配体系的性质, 并分别采用Rubingh-Margules模型和Rubingh-正规溶液模型计算了临界胶束浓度和混合胶团组成. 研究发现, 两表面活性剂分子结构的匹配性及带电头基之间的相互作用是影响混合溶液性质的主要因素. 对于分子结构差别较大的C12mimBr与Gemini 12-3-12的混合, 其行为远远偏离理想混合性质; 对疏水链长相同仅亲水头基不同的C12mimBr与DTAB则接近于理想混合; 而对C12mimBr+SDS的复配体系, 正、负电荷间强烈的相互吸引使得混合体系大大偏离理想行为. 计算发现, 两种理论模型得到的混合胶团组成基本一致, 但Rubingh-Margules模型预测的临界胶束浓度比Rubingh-正规溶液模型要好  相似文献   

9.
研究了在高盐油藏中, 利用两性/阴离子表面活性剂的协同效应获得油水超低界面张力的方法. 两性表面活性剂十六烷基磺基甜菜碱与高盐矿化水具有很好的相容性, 但在表面活性剂浓度为0.07%-0.39%(质量分数)范围内仅能使油水界面张力达到10-2 mN·m-1量级, 加入阴离子表面活性剂十二烷基硫酸钠后则可与原油达到超低界面张力. 通过探讨表面活性剂总浓度、金属离子浓度、复配比例对油水动态界面张力的影响, 发现两性/阴离子表面活性剂混合体系可以在高矿化度、低浓度和0.04%-0.37%的宽浓度范围下获得10-5 mN·m-1量级的超低界面张力, 并分析了两性/阴离子表面活性剂间协同获得超低界面张力的机制.  相似文献   

10.
聚酰胺-胺(PAMAM)是目前最具应用前景的树枝状大分子(Dendrimer),它与表面活性剂相互作用后能够形成聚集体,这种聚集体能有效地改变体系的微观环境和物理化学性质。本文综述了小分子表面活性剂与Dendrimer相互作用研究方面所取得的进展,重点讨论了阴离子表面活性剂和阳离子表面活性剂与Dendrimer混合体系中溶液的疏水环境、浊度以及形成的聚集体的中值粒径等物理化学性质的变化,在此基础上,讨论了Dendrimer与小分子表面活性剂相互作用机理研究所取得的进展,为进一步扩大Dendrimer的应用领域提供参考。  相似文献   

11.
Mori I  Fujita Y  Ikuta K  Nakahashi Y  Kakimi E  Kato K 《Talanta》1989,36(6):688-690
Complex formation between uranium or tungsten and o-hydroxyhydroquinonephthalein (Qnph) in various micellar surfactant media has been investigated fluorometrically, and determination of uranium and tungsten based on the difference between the relative fluorescence intensities of Qnph and the metal complex at 535 nm, with excitation at 400 nm in the presence of poly(vinyl) alcohol as a non-ionic surfactant. The calibration curves were linear up to 1.0 mu/ml uranium and 0.9, mu/ml tungsten. The relative standard deviations (5 replicates) were 2.6% for tungsten and 3.0% for uranium, and recovery tests gave relatively good results (97-104%).  相似文献   

12.
Hung SC  Qu CL  Wu SS 《Talanta》1982,29(7):629-631
A highly sensitive method for spectrophotometric determination of uranium has been devised. The method is based on formation of a red-violet 1:2 (metal:ligand) complex from the reaction of uranium(VI) with 2-(3,5-dibromo-2-pyridylazo)-5-diethylaminophenol (3,5-diBr-PADAP) in the presence of an anionic surfactant, sodium lauryl sulphate. Its molar absorptivity is found to be 9.1 x 10(4)l.mole(-1).cm(-1). The absorbance is constant in the range pH 8.4-9.9 Beer's law is obeyed for 0-1.4 mug/ml concentrations of uranium. In the presence of DCTA the method is selective for uranium, and can be used for the determination of trace amounts of uranium in water samples.  相似文献   

13.
Carvalho MS  Fraga IC  Neto KC  Silva Filho EQ 《Talanta》1996,43(10):1675-1680
The present work describes a selective, rapid and economical method for the determination of cobalt using the 2-(2-benzothiazolylazo)-p-cresol (BTAC) as a spectrophotometric reagent associated with a solid extraction on polyurethane foam. The BTAC reacts with Co(II) in the presence of Triton-X100 surfactant forming a green complex with maximum absorption at 615 nm. The reaction is used for cobalt determination within a pH range of 6.50-7.50, with an apparent molar absorptivity of 1.62 x 10(4) L mol(-1) cm(-1). Beer's Law is obeyed for a concentration of at least 1.60 microg ml(-1). A selective procedure is proposed for cobalt determination in the presence of Fe(II), Hg(II), Zn(II) and Cu(II) up to milligram levels using masking agents. Polyurethane foam is used for the preconcentration and separation of cobalt from thiocyanate media and this procedure is applied to its determination in nickel salts and steel alloys.  相似文献   

14.
A flow injection system for the simultaneous determination of uranium and thorium has been developed by using selective masking and a spectrophotometric detector with two flow cells aligned with the same optical path. The injected sample solution was first mixed with a reagent solution containing Chromazurol S (CAS) and cetyltrimethylammonium chloride (CTMAC), and the total absorbance of uranium- and thorium-CAS complexes was measured in the first flow cell at 620 nm. The sample stream was then mixed with an EDTA solution in order to convert the thorium-CAS complex to a thorium-EDTA complex, and the absorbance of the uranium-CAS complex was measured in the second flow cell. The detection limits were 10 microg dm(-3) for uranium and 7 microg dm(-3) for thorium. The calibration graphs were linear (r < 0.9998) at least over the ranges of 0.1 to 10 mg dm(-3) for uranium and 0.08 to 8 mg dm(-3) for thorium. The RSDs were less than 1.5% (n = 3) in the calibration range. Uranium and thorium of up to the 6-fold concentration to each other could be determined in admixtures with relative errors of less than 3.3%. The sample throughput was 24 per hour. The proposed system was successfully applied to the analysis of a uranium-thorium ore mock solution by coupling with anion-exchange in a magnesium nitrate medium to eliminate interference from coexisting elements.  相似文献   

15.
在微酸性溶液中钪与甘氨酸邻甲酚红(GCR)和溴化十六烷基三甲铵(CTMAB)形成红紫色的三元络合物。在其最大吸收波长540nm处的表观摩尔吸光系数为4.14×104。三元络合物的络合比为SC:GCR:CTMAB=1:2:2。当以乙酰丙酮及邻菲啰啉为联合掩蔽剂时,大量稀土元素及10余种共存元素不干扰钪的测定。用本法测定了合成的混合稀土样品中的少量钪,得到了较满意的结果。  相似文献   

16.
头发中微量铜和锌的 5-Br-PADAP 分光光度法测定   总被引:5,自引:1,他引:4  
研究了测定铜和锌时多种掩蔽剂联合掩蔽头发中的干扰离子。测定铜时用六偏磷酸钠和焦磷酸钾联合掩蔽;测锌时用柠檬酸钠、六偏磷酸黄和铜试剂联合掩蔽。在表面活性剂OP存在下,5-Br-PADAP显色,不经分离,直接在水事测定斑秃患者头发中的铜和锌。铜络合物的最高吸收峰在558nm,锌络合物的最高吸收峰在560nm,在25mL溶液中,铜在0-37.5mg/L,锌在0-238mg/L范围内符合beer定律。斑秃患者头发中锌和铜低于正常人。  相似文献   

17.
《Analytical letters》2012,45(10):1989-1998
Abstract

A sensitive and selective spectrophotometric flow injection analysis (FIA) method with chlorophosphonazo-mN has been developed for the determination of uranium(VI) in standard ore samples. Most of interfering ions are effectively eliminated by the masking reagent of diethylenetriaminepentaacetic acid (DTPA). In the U(VI)-chlorophosphonazo-mN system, the maximum absorption wavelength is at 680 nm and Beer's law is obeyed in the range of 1 to 15 μg ml?1. The correlation coefficient of the calibration curve is 0.9998, the sampling frenquency is 60 h?1, and the detection limit for uranium(VI) is 0.5 μg ml?1. The composition of the U(VI)-chlorophosphonazo-nN complex was established to be 1:2 by flow-through spectrophotometric and conventional molar ratios methods.  相似文献   

18.
本文研究了铀-2-(3,5-二溴-2-吡啶偶氨)-5-二乙氨基苯酚(3,5-diBr-PADAP)-Triton X-100析相光度体系,建立了矿石中微量铀的测定方法,在pH 7.5三乙醇胺-盐酸介质中,将胶束溶液在 95±1℃加热 1h.络合物即被Triton X-100相完全富集.络合物最大吸收峰位于565nm.摩尔吸光系数为1.02×10~5L·mol~(-1)·cm~(-1),铀含量在0~12μg/5mL服从比耳定律.采用TBP萃淋树脂分离干扰离子,测定矿石中微量铀,结果满意.  相似文献   

19.
铀的高灵敏高选择性的光度法尚少见。最近有人合成过二溴苯基萤光酮(下简称Br-PF),但未见用于测定铀的报导。为此,本文研究了在吐温-60存在下用Br-PF测定铀的条件,结果表明,本法的灵敏度较高(ε=1.79×105),是迄今为止铀最灵敏的显色反应(见表1)。采用三辛胺(TOA)萃取分离铀,并用于岩矿中铀的测定。  相似文献   

20.
An improved spectrophotometric determination of uranium(VI) is proposed using 4-(2-pyridylazo)resorcinol(PAR) in the presence of benzyldimethylstearyltrimethylammonium chloride(BSTAC) as a cationic surfactant. The calibration graph is linear in the range of 0.3-60 microg/10 ml uranium(VI), measuring the absorbance at 550 nm. The reproducibility for 19.0 microg/10 ml uranium(VI) is 0.57%. The third-derivative method using the third-derivative distance (d(3)A/dlambda(3)) among lambda(1) 530 nm, lambda(3) 594 nm and lambda(2) 565 nm was also investigated.  相似文献   

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