胶束液相色谱

胶束液相色谱(micellar liquid chromatography),又叫假相液相色谱(pseudophase liquid chromatography),使用高于临界胶束浓度(CMC)的表面活性剂溶液作流动相,代替液相色谱传统的水-有机物流动相。胶束流动相不仅具有毒性小(避免使用甲醇、乙腈)、消     

胶束反相高效液相色谱最佳化研究

本文介绍以YWG-C_(18)为固定相,十二烷基硫酸钠(SDS)胶束溶液为移动相,探讨了SDS浓度和柱温对胶束反相高效液相色谱分离最佳化的影响。测定了胶束体系中苯胺的热力学函数ΔH~0值及SDS的临界胶束浓度(C.M.C.),还讨论了非极性和极性溶质的保留机理。     

阴离子型胶束液相色谱的溶质保留行为

以SDS阴离子表面活性剂作流动相,酸性、中性及两性药物为受试药物,运用三相平衡理论考察影响阴离子型胶束液相色谱（AMLC）溶质保留行为的几个因素。保留由溶质与胶束相及修饰后固定相的综合作用决定。有机调节剂正丙醇的加入改变了溶质从水相到固定相或到胶束相的平衡,保留取决于溶质疏水性和静电性间的平衡。此外对羟基苯甲酸酯类同系物的亲脂性与3种细菌最小抑菌浓度具有显著相关性,提示其抑菌机理主要取决于药物与生物膜的亲和性。     

胶束溶液在液相色谱中作为流动相的研究——Ⅰ.在药物薄层色谱分离中的应用

1979年,Armstrong等开始将胶束溶液作为薄层色谱和高效液相色谱的流动相。     

胶束溶液体系对毛细管电动色谱酸性化合物分离的影响

以阴离子表面活性剂十二烷基硫酸钠（SDS）、非离子表面活性剂吐温20（ Tween 20）及两者组成的混合胶束体系作为毛细管胶束电动色谱（MECC）的分离介 质，进行4种结构相似的酸性化合物的MECC分离研究，考察了胶束的类型、表面活 性剂的浓度、缓冲溶液的pH值及有机改性剂乙醇对分离的影响。结果表明各因素对 酸性药物的MECC分离有不同的影响规律。SDS胶束体系对溶质的保留值最大， Tween 20体系的保留值最小，二者的分离选择性正好相反，混合胶束体系的分离行 为则介于两者之间；在SDS和Tween 20体系中，表面活性剂浓度增加，溶质的保留 时间均随之递增，混合胶束体系中，总浓度一定，随Tween 20配比的增加，溶质的 保留时间先减少后增加；缓冲溶液的pH值增大，使溶质的分离效果均能变差；有机 改性剂乙醇的加入对容量因子的影响主要与溶质的疏水性有关，并对分离作用机理 进行了探讨。在SDS和Tween 20 MECC体系下，分别进行了实样测定，取得了满意的 结果。     

一种新型的色谱法——毛细管胶束电动色谱法

本文介绍了毛细管胶束电动色谱法的原理,建立了一套电动色谱实验装置。采用十二烷基硫酸钠(SDS)胶束溶液。对电中性有机化合物进行了电动色谱试验,获得了较好的结果。并考察了实验条件如电压、SDS浓度等对分离的影响。     

胶束电动毛细管色谱双通道电化学检测尼群地平

创建了尼群地平的胶束电动毛细管色谱双通道电化学检测的分析新方法。采用 两台安培检测器并联构成双通道检测系统，采用单一碳糊工作电极，两台安培检测 器的检测电位分别设为+0.7V和-0.8V(vs.SCE)同，同时对尼群地平进行氧化和还原 测定，并实时对数据进行采集、处理，以图形方式显示。采用NH3－NH4Cl为背景电 解质，并加入十二烷基硫酸钠（SDS）和甲醇组成运行电泳介质，应用氧化、还原 双通道检测系统对尼群地平及其片剂进行了胶束电动毛细管色谱分离检测；对工作 电极的选择、电极电位的选择、SDS的浓度、甲醇浓度、运行缓冲溶液种类以及工 作电压和进样时间对分离检测的影响进行了研讨，取得满意结果。     

二苯胺重氮盐,重氮树脂与表面活性剂的相互作用及基于重氮树脂的超薄感光膜的研究

重氮树脂(DR)是二苯胺-4-重氮盐(DDS)与甲醛的缩合产物,它是最重要的阴图胶印版的感光剂.DR和DDS的缺点是热稳定性差,特别是在水中.本论文第一部分内容是关于DDS和DR与表面活性剂相互作用的研究.研究结果表明:DR和DDS的热稳定性在阴离子表面活性剂十二烷基硫酸钠(SDS)水溶液中得到显著提高.原因是DDS和DR分子与SDS分子间的疏水相互作用和静电吸引作用使它们可以进入SDS的胶束相,同SDS分子共同形成混合胶束.所以DR和DDS在S DS水溶液中存在胶束相和水相的分配平衡.处于胶束相的DDS或DR,由于胶束的静电及极性效应使它们的重氮基得到保护.进入胶束相的DDS和DR的量越多,它们水溶液的热稳定性提高越显著.由于DDS和DR与SDS间较强的相互作用使SDS浓度(≈10-5mol/L)在远低于临界胶束浓度(8×10-3mol/L)时形成了混合预胶束,预胶束对DDS和DR同样具有保护作用.     

泽泻乙醇提取物的HPCE分离研究

采用高效毛细管电泳的胶束电动毛细管色谱的分离模式(MEKC),对泽泻的乙醇(95％)提取物进行分离研究。以十二烷基硫酸钠(SDS)胶束为准固定相．硼砂为缓冲体系,甲醇为有机添加剂,考察了SDS浓度、硼砂浓度、pH、甲醇用量、电泳电压、电泳温度等对分离的影响。结果表明：硼砂缓冲体系为运行缓冲溶液(pH：9．18～9．20)、硼砂浓度30mmoL／L、SDS浓度45mmol／L、甲醇体积分数30％,分离电压25kv、分离温度25℃时分离效果最好。在此条件下,得到分离度和重现性均较好的泽泻乙醇提取物的HPCE色谱图。     

静电离子色谱用于硼酸溶液中硼不同形态组分分离的研究

改进了把胆汁酸诱导体胶束(CHAPSO)涂覆在ODS载体上制备静电离子色谱固定相的方法.以纯水为流动相,采用示差折光检测器,研究了硼酸溶液中硼的形态、分离条件,并对色谱峰进行了解析.此外,还对硼酸溶液中硼离子、硼分子的色谱保留行为进行了探讨.     

High-performance liquid chromatographic determination of diuretics in urine by micellar liquid chromatography.

The use of micellar liquid chromatography for the determination of diuretics in urine by direct injection of the sample into the chromatographic system is discussed. The retention of the urine matrix at the beginning of the chromatograms was observed for different sodium dodecyl sulphate (SDS) mobile phases. The eluent strengths of a hybrid SDS-methanol micellar mobile phase for several diuretics were compared and related to the stationary phase/water partition coefficient with a purely micellar mobile phase. The urine band was appreciably narrower with a mobile phase of 0.05 M SDS-5% methanol (v/v) at 50 degrees C (pH 6.9). With this mobile phase the determination of bendroflumethiazide and chlorthalidone was adequate. Acetazolamide, ethacrynic acid, furosemide, hydrochlorothiazide and probenecid were overlapped by the urine matrix, and the retention of amiloride and triamterene was too long.     

Conventional and thermal lens spectrophotometric determination of p-aminobenzoic acid and arylamine diuretics previous azodye formation in a micellar medium

The determination of the diuretics hydrochlorothiazide, bendroflumethiazide and furosemide by both conventional and thermal lens spectrophotometry (TLS, 100 mW of pump power at 514.5 nm) following previous hydrolysis, diazotization and coupling with N-(naphthyl)ethylenedine (NED) in a sodium dodecyl sulphate (SDS) micellar medium of pH approximately 1 was studied. p-Aminobenzoic acid (PABA) was used as a model compound to optimize the derivatization procedures. 3-Substituted indoles, such as 5-hydroxyindole-3-acetic acid and tryptophan, gave N-nitroso derivatives which interfered with the determination of the diuretics in urine. The derivatized diuretics in urine were separated using HPLC with a Spherisorb ODS-2 C(18) column, and a 0.1M SDS mobile phase containing 5% n-propanol and 0.001M sodium dihydrogen phosphate (pH 3). The diuretics gave limits of detection (LODs) of ca. 5 x 10(-9)M for the TLS procedure. The LODs were 20-50-fold higher for the corresponding spectrophotometric procedure.     

Use of micellar mobile phases and microbore column switching for the assay of drugs in physiological fluids

The feasibility of directly assaying drugs in physiological fluids using on-line preconcentration and microbore high-performance liquid chromatography has been demonstrated. The untreated sample is injected onto a hydrophobic pre-column, using micellar sodium dodecyl sulfate (SDS) in the case of serum or phosphate buffer in the case of urine, as the load mobile phase. This traps the components of interest which are then backflushed onto a microbore analytical column using a stronger mobile phase. This procedure was then applied to diazepam in serum and phenobarbital in urine. Recovery was linear and quantitative over the range 30-3000 ng/ml for diazepam in serum and 2-200 micrograms/ml for phenobarbital in urine. The diazepam method was specific against caffeine and the three major metabolites of diazepam: oxazepam, temazepam, and nordiazepam. The effects of varying pre-column dimensions, pre-column loading time, and SDS concentration volume were evaluated.     

Use of a three-factor interpretive optimisation strategy in the development of an isocratic chromatographic procedure for the screening of diuretics in urine samples using micellar mobile phases

Screening of diuretics in urine is feasible through direct injection of the samples into the chromatographic system and isocratic reversed-phase liquid chromatography (RPLC) with micellar-organic mobile phases of sodium dodecyl sulfate (SDS) and 1-propanol. The surfactant coverage of the chromatographic column makes the addition of organic competing amines less necessary than in conventional aqueous-organic RPLC to achieve well-shaped peaks. Also, the range of elution strengths of micellar mobile phases required to elute mixtures of hydrophobic and hydrophilic diuretics is smaller. This allows the isocratic separation of the diuretics within adequate analysis times. An interpretive methodology is applied to optimise the resolution of a mixture of 15 diuretics of diverse polarity and acid-base behaviour (althiazide, amiloride, bendroflumethiazide, benzthiazide, bumetanide, canrenoic acid, chlorthalidone, ethacrynic acid, furosemide, piretanide, probenecid, torasemide, triamterene, trichloromethiazide and xipamide), using pH and concentrations of surfactant and organic modifier in the mobile phase as separation factors. Twelve diuretics were resolved in 25 min using 0.055 M SDS-6.0% 1-propanol at pH 3.0. The mixture of 15 diuretics was also resolved with two mobile phases showing complementary behaviour: 0.05 M SDS-5.6% 1-propanol at pH 5.4 and 0.11 M SDS-5.4% 1-propanol at pH 4.2. The results were applied to the analysis of urine samples with limits of detection similar to those usually reported for aqueous-organic RPLC, taking into account that the samples were injected without any previous treatment to separate or preconcentrate the analytes.     

Determination of Steroids in Human Urine by Micellar Liquid Chromatography

Abstract

A simple and sensitive method for the determination of steroids using micellar liquid chromatography is described. The steroids, including hydroxycorticosterone. corticosterone, northisterone, testosterone, mexdroprogesterone acetate and progesterone, were separated by reversed-phase using a micelles mobile phase following UV detection at 245 nm. The parameters affecting retention of the test solutes such as the concentration of sodium dodecyl sulfate (SDS) and n-butanol-1 in the mobile phase were investigated. It was found that the retention of the solutes was dependent on the composition of mobile phase. The linear calibration plots range from 0.1 to 10 μg ml^?1 in mobile phase containing 5.0 × 10^?2 mol l^?1 SDS/9 % n-butanol-1 at pH 6.0, and the detection limit in order of 0.1 μg ml^?1 was obtained. The proposed method was used for the determination of steroids in urine using direct injection of samples without previous treatment.     

Development and validation of a method to determine amoxicillin in physiological fluids using micellar liquid chromatography

A simple and robust method was developed for the routine identification and quantification of amoxicillin by micellar LC. Amoxicillin, a beta-lactamase inhibitor, is one of the most commonly prescribed drugs in the treatment of urine and skin structure infections. In this work, amoxicillin was determined in urine samples without any pretreatment step in a phenyl column using a micellar mobile phase of 0.10 M SDS and 4% butanol at pH 3. A UV detection set at 210 nm was used. Amoxicillin was eluted at 5.1 min with no interference by the protein band or endogenous compounds. Linearities (r >0.9998), intra- and interday precisions were determined (RSD (%) 0.4-2.7% and 0.3-5%, respectively, in micellar media, and 0.14-2.6% and 0.13-6%, respectively, in urine), and robustness was studied in the method validation. LOD and LOQ were 0.04 and 0.1 microg/mL in micellar media and 0.14 and 0.34 microg/mL in urine, respectively. Recoveries in the urine matrix were in the range of 95-110%. The validated method proved to be reliable and sensitive for the determination of amoxicillin in urine samples.     

Determination of trazodone in urine and pharmaceuticals using micellar liquid chromatography with fluorescence detection

A simple and reliable liquid chromatographic procedure is described for the determination of trazodone in pharmaceutical formulations and urine samples. The optimized procedure uses fluorimetric detection, a C18 column and a micellar mobile phase of sodium dodecyl sulfate (SDS) and 1-butanol. The mobile phase selected for use was 0.2M SDS and 8% 1-butanol fixed at pH 3 with phosphate buffer. The total analysis time was 10 min. For the analysis of urine samples, one great advantage of the method is that no extraction step is required. The quantification limit was 9.5 ng mL(-1), ensuring the analysis of the drug in biological fluids. The procedure shows good accuracy, repeatability and selectivity. Repeatability and intermediate precision were tested for several concentrations of the drug. Good claim percentages were obtained in the analysis of pharmaceutical formulations. Calibration repeatability in urine matrix was also studied in the 0.06-22.4 microg mL(-1) range. Good recoveries were obtained from spiked urine samples. No interferences from common additives frequently administered with trazodone or from endogenous compounds in urine samples were found. The results show that the procedure is suitable for routine analysis of the drug.     

基于一种新型有机聚合物整体柱的毛细管电色谱技术用于利尿剂的分离与检测

采用自制的新型有机聚1-十六碳烯-三羟甲基丙烷三甲基丙烯酸酯［poly(1-hexadecene-co-TMPTMA)］整体柱,建立了一种同时分离检测6种利尿剂(氯噻酮、氢氯噻嗪、美托拉宗、吲哒帕胺、坎利酮和螺内酯)的毛细管电色谱(CEC)新方法,并成功应用于志愿者实际尿样的分析测定。在最佳实验条件下,6种利尿剂包含2种中性物质(坎利酮和螺内酯)和2种同分异构体(美托拉宗和吲哒帕胺)在11.0 min内得到基线分离,柱效分别达到218000、176000、143000、121000、108000、103000 塔板/m。6种利尿剂在1.15～86.0 μg/mL范围内呈良好的线性关系,相关系数R2 ≥0.990 8,检出限(LOD)在0.35～0.65 μg/mL范围内,回收率为81.9%~105%,相对标准偏差(RSD)小于4.7%。结果表明,实验所建立的基于poly(1-hexadecene-co-TMPTMA)整体柱的CEC方法,具有良好的重复性和稳定性,能够实现对多种利尿剂的同时分离检测。该方法已成功应用于来自志愿者实际尿样的分析,该方法可以用于利尿剂类药物的初筛。     

Separation and mechanism elucidation for six structure-like matrine-type alkaloids by micellar liquid chromatography

A mixed micellar liquid chromatography (MLC) method, the mobile phase consisting of anionic surfactant SDS and nonionic surfactant Brij35, was firstly developed for the separation and determination of six structure-like matrine-type alkaloids, including matrine, oxymatrine, sophocarpine, oxysophocarpine, sophoridine, and oxysophoridine. The factors influencing the resolution of the six alkaloids were systematically investigated and optimized, including the micellar composition and concentration, column temperature, the type and amount of organic solvent, and the pH values in the mobile phases. Under the optimized separation conditions, the six matrine-type alkaloids could be easily isocratically eluted with a baseline separation within 22 min. Under the designated conditions (SDS concentration from 10 to 50 mM, Brij35 from 5 to 30 mM, pH 3 and 5% 1-propanol), the hydrophobic selectivity was negatively correlated with the concentration of Brij35 but not with SDS. The functional group selectivity of the carbonyl group, double bond, and diastereomers, all decreased with the increase in percentage of SDS in the mixed micellar phase, because the strong electrostatic force masks other molecular forces which can discriminate the retention of the analytes. Therefore, such a combination in surfactants of MLC is a powerful strategy to increase the selectivity by adjusting the balance among the various molecular interaction forces influencing analytes' retention. Finally, the developed method was successfully used to separate and determine the contents of main alkaloids in Sophora medicinal plants, S. flavescens Ait. In summary, the mixed MLC is a valuable approach to separate and determine the structure-like multi-component natural samples.