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1.
表面活性剂阴离子双水相新体系及其对卟啉、染料的萃取 总被引:1,自引:0,他引:1
由阴阳离子型表面活性剂水溶液混合形成的双水相[1,2]是水相分离技术中的一个新分支.ZHAO等[2]将阴阳离子表面活性剂过量的体系分别称为阴阳离子双水相.由溴化十二烷基三乙铵(C12NE)和十二烷基硫酸钠(SDS)组成的阳离子双水相对蛋白质[1]、酶[3]、氨基酸[4]和卟啉[5,6]等的萃取分离已有报道.与阳离子双水相比较,阴离子双水相分相时间慢,其萃取应用研究尚未见报道.本文在详细研究了SDS-C12NE阴离子双水相的基础上,将全氟型阴离子表面活性剂全氟辛酸钠(SPFO)引入这类水相分离体系… 相似文献
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HDEHP萃取Ga(Ⅲ)的动力学 总被引:3,自引:0,他引:3
用生长液滴法研究了HDEHP在盐酸介质中萃取Ga(Ⅲ)的动力学,结果表明,萃取反应速率取决于发生在界面区域内两步连续反应Ga3++Ai-=GaAi2+GaAi2++Ai-=GaA2+i研究了阴离子表面活性剂SDS、ABS对HDEHP萃取Ga(Ⅲ)的影响,二者均不改变HDEHP萃取Ga(Ⅲ)的分配比,但使其正向萃取初始速率降低,原因是表面活性剂与萃取剂在界面上发生了竞争吸附;其次是表面活性剂的加入导致了界面膜上分子排列更致密和界面膜增厚,产生了更大的传质阻力。 相似文献
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DTAB-月桂酸钠体系表面活性剂双水相研究 总被引:4,自引:0,他引:4
绘制和分析了十二烷基三甲基溴化铵(DTAB) 月桂酸钠(SL)组成的表面活性剂混合体系相图,系统研究了温度和无机盐等因素对该体系表面活性剂双水相 (ASTP) 影响的规律性.结果表明:与富含负离子表面活性剂双水相 (ASTP A) 相比较,富含正离子表面活性剂双水相(ASTP C)区域更大、更稳定;温度升高,无机盐(NaBr)的浓度增大,都引起 ASTP 体系上相体积的减小和下相体积的增加;囊泡普遍存在于ASTP的上下相之中. 相似文献
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外加盐作用形成的正负离子表面活性剂双水相 总被引:1,自引:0,他引:1
癸基三乙基溴化铵-癸基磺酸钠(C10NE-C10SO3)等摩尔混合均相体系(即使在表面活性剂总浓度高达0.2 mol•L-1时仍然可形成稳定的均相溶液)在外加盐NaF、Na2SO4和Na3PO4的作用下可自发分离成两个水相(双水相).研究了该类双水相体系的形成、相行为及其对牛血清蛋白(BSA)的分配,并与普通的正负离子表面活性剂混合双水相体系进行了比较.结果表明,该类双水相体系克服了普通的正负离子表面活性剂混合双水相体系的一些不足,具有一些独特的优点.该类双水相体系的相行为可以通过外加盐进行调控,通过外加盐的种类来调控和优化BSA的分配行为.图1表2参8 相似文献
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盐酸溶液中阴离子表面活性剂在铝表面上的吸附 总被引:2,自引:0,他引:2
用失重法研究了盐酸溶液中阴离子表面活性剂十二烷基磺酸钠(DSASS),十二烷基苯磺酸钠(DBSAS)以及十二烷基硫酸钠(SDS)在铝表面上的吸附作用,提出这种吸附作用与铝的失重量有关,且符合Lang-muir方程,计算出吸附热,吸附熵和吸附自由能等热力学参数。认为这种吸附主要靠静电作用,根据接触角的变化讨论了阴离子表面活性剂分子在铝表面上的吸附取向。 相似文献
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meso—四(4—磺基苯基)卟啉双波长分光光度法测定阳离子表面活性剂 总被引:10,自引:0,他引:10
在酸性条件下,阳离子表面活性剂使meso-四(4-磺基苯基)卟啉(TPPS4)发生J-型聚合,在490nm处出现J-型聚集吸收并导致位于434nm的Soret吸收带降低。阴离子表面活性剂如十二烷基硫酸钠(SDS)使聚集更一步增强,据此建立起水中痕量阳离子表面活性剂的双波长分光光度测定,方法成功地应用于合成和实际水样分析。 相似文献
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本文报道N,N-二乙基甲酰胺代甲基膦酸二正己酯(简称E)萃取金(Ⅱ)的各种参数,如分配比、振荡时间、相比、水相酸度及酰的种类,以及其它离子对萃取金(Ⅲ)分配比的影响。并求得了达到平衡时化合物E萃取金反应的焓变(OH)和熵变(OS)。 相似文献
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A simple and simultaneous analysis method for four (anionic, amphoteric, nonionic, and cationic) classes of surfactants in shampoo and hair conditioner was newly developed. Analysis of the surfactants was performed using a reversed-phase HPLC (RPLC) combined with evaporative light scattering detection (ELSD) without any pre-treatment. An optimum analysis condition for the resolution of both four main surfactant mixtures used in shampoo and five main surfactants used in hair conditioner could be established under a gradient mobile phase condition with acetonitrile, tetrahydrofuran and water. The detection limits were 2.5-30 μg mL−1 except for SLES (150 μg mL−1), and the calibration curves, i.e. the log-log plots, were linear in the working range of 2.5-5250 μg mL−1 with R2 values of above 0.998. The observed precision was less than 5% R.S.D. The elution peaks were identified by a liquid chromatography-mass spectrometer (LC-MS) equipped with an electrospray interface operating in mixed-mode. 相似文献
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A simultaneous separation of cationic, amphoteric and nonioinc nine surfactants (DMDS, DMDP, DMDM, DMDL, BZC, CDE, A/O, SUNC, IMD) has been performed by a reverse phase-HPLC method utilizing a single J'sphere ODS (250 mm × 4.6 mm, 4 μm) column and a methanol-water containing 0.2% TFA eluent system within 60 min. The observed precision in determination of concentration was less than 5% R.S.D., which revealed that ELSD was an effective tool to detect the various studied surfactants of low volatility without chromophore. In addition, the detection limits were in the concentration range of 3.5-10 μg/mL, and the calibration curves, i.e. the log-log plots, were linear in the working range of 5-4600 μg/mL with the slopes of 1.321-1.668. The application of the analytical procedure to three household products without pretreatment supported that the presented chromatographic method was simple to be practical for a routine analysis of commercial products. 相似文献
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Separation of inorganic anions by capillary electrophoresis (CE) is usually conducted in co-electroosmotic mode due to the large electrophoretic mobilities of inorganic anions. Semipermanent surfactant coatings have been shown to be effective for CE of inorganic anions due to their strong capability of electroosmotic flow (EOF) manipulation. However, semipermanent coatings often suffer from their unsatisfactory stability. In addition, organic solvent additives are usually required to adjust the selectivity, which also aggravate the degradation of coating. In this work, a novel semipermanent coating consisting of cationic Gemini surfactant 18-10-18 and nonionic surfactant Tween 20 was developed to separate inorganic anions in CE. This coating is easy to prepare and more stable than pure Gemini coating. The introduction of nonionic surfactant in the coating not only suppresses the reversed EOF but can also adjust the selectivity of separation. Good separations of six model anions were achieved, the separation efficiency was as high as 65040-169700 plates/m and the RSDs of the migration times were less than 0.5 and 2.5% for run-to-run and day-to-day assays, respectively. Calibration curves were linear in the range of 0.05-5.0 mM; the detection limits ranged from 20 to 50 μM. More importantly, no organic solvents are required in the background buffer to achieve the satisfactory separations. This guarantees the coating stability and makes the method greener than most of other methods for CE of inorganic anions. 相似文献
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《Analytical letters》2012,45(1):87-99
Abstract A simple method is described for the determination of residual organic acids, used as catalyst neutralizers, in alkylphenolethoxylates. The detection limit is 12 ppm. Method validation data is included. Commercially produced surfactants were analyzed and found to contain acetate in the range 600 ppm to 2300 ppm. 相似文献
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The desorption kinetics of sodium dodecyl sulfate (SDS) from nylon particles was investigated by applying the stopped-flow technique. A stopped-flow spectrophotometer commercially available was modified in order to study the desorption kinetics of ionic surfactants from solid surfaces in aqueous solutions. The modification provided a mixing cell with platinum electrodes for electric conductivity detection. Nylon particle suspensions containing various concentrations of SDS were rapidly diluted with distilled water by using the modified mixing apparatus. The changes in specific electric conductivity with time were monitored by a memory-recorder system. It was found that the rate constant in the early stage of desorption could be accurately determined by the modified stopped-flow method. 相似文献
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Determination of nucleic acid based on increased resonance light-scattering of fluorinated surfactants 总被引:1,自引:0,他引:1
Ling Li 《Journal of fluorine chemistry》2009,130(6):567-728
Two novel surfactants perfluoroalkanesulfonyl quaternary ammonium iodides (FC134) and potassium perfluorooctanesulfonate (FC95) were successfully used as new probes for detection of DNA by resonance light-scattering (RLS) technique. Resonance light-scattering characteristics of the binding of fluorinated surfactants FC134 and FC95 to calf thymus nucleic acid (ctDNA) were studied. After DNA was added, aggregation of FC134 on the molecular surface of DNA in the pH 3.0-6.0 and aggregation of FC95 on the surface of DNA in the pH 3.5-6.0 occurred, both of which resulted in an enhanced resonance light-scattering peak at 370 nm. The intensity of resonance light-scattering was found to be proportional to the concentration of DNA. The determination limits were 3.5 and 20.0 μg L−1, respectively. UV-vis spectra and IR-spectra both proved the binding of fluorinated surfactants to DNA. 相似文献
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A simple, rapid and low-costing new mixed surfactant MEKC method has been developed for the analysis of five neutral anabolic steroids in this paper. It was found that the bile salt coupling with Triton X-100 was a suitable bi-micellar surfactant for the separation of these anabolic steroids with similar structure. The separation conditions were optimized in detail. The five natural and synthetic anabolic steroids, such as androstenedione (AD), 19-norandrostenedione (NAD), 1,4-androstadiene-3,17-dione (ADD), methandrostenolone (MA) and methyltestosterone (MT) were separated and detected in an alkaline buffer system (pH 9.0) containing 15 mM Britton-Robinson (BR) buffer, 50 mM sodium cholate (SC) and 0.1% (v/v) Triton X-100 with detection wavelength at 241 nm and 18 kV of separation voltage. Under the optimal conditions, five coexistence neutral steroids were completely separated within 12 min with the detection limits ranged from 0.20 to 0.51 μg/mL. This method was successfully used for detection and confirmation of the anabolic steroid methandrostenolone in methandrostenolone tablets and in the real human urine, GC-MS method was applied to confirm the free methandrostenolone existence in the urine sample in order to validate the reliability of MEKC method. 相似文献
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对GB/T 7494–1987测定地表水中阴离子表面活性剂含量的方法进行优化。对萃取次数、磷酸二氢钠溶液反洗以及pH调节等进行了试验研究,将萃取用的三氯甲烷总量降为25 mL,两次萃取定容后一次反洗。结果表明,萃取两次可以满足分析需求,反洗能够有效去除亚硝酸盐氮等离子干扰,中性地表水样品无需调节pH,非中性样品须调为中性后测定。方法优化后线性良好,线性相关系数大于0.999,检出限为0.012 mg/L。测定结果的相对标准偏差为0.8%~3.3%(n=6),加标回收率为92.0%~110.0%。优化后方法满足地表水分析要求,能有效降低三氯甲烷用量并简化分析步骤。 相似文献
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IntroductionTriazenereagentsareinterestingbecauseoftheirstrongcomplexationabilitieswithtransitionmetals .1 6However,littledecolorationofthemcatalyzedbysilverionhasbeenstudiedinanalyticalchemistry .Manyanal ysistshavereportedtheuseofcatalyticreactionsfort… 相似文献
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Ozge Selcuk Cem Erkmen Dr. Burcin Bozal-Palabiyik Prof. Dr. Bengi Uslu 《Electroanalysis》2021,33(5):1290-1298
In this study, a differential pulse voltammetry method was designed for the simultaneous determination of etodolac and thiocolchicoside in a tablet dosage form. This method is a sensitive, costless and reproducible one initially designed for the simultaneous determination of etodolac and thiocolchicoside using bare/unmodified glassy carbon electrode in the presence of sodium dodecyl sulfate. At optimized conditions, the method showed linear responses with etodolac and thiocolchicoside concentration in the range of 1 μM to 80 μM. The limits of detection and quantification were calculated as 0.11 μM and 0.38 μM for etodolac and 0.20 μM and 0.67 μM for thiocolchicoside, respectively. 相似文献