Cyclodextrin-Modified Gold Nanoparticle Capillary Electrochromatography with Online Sample Stacking for Simultaneous and Sensitive Determination of Aminobenzoic Acid Isomers

A newly-developed method of complete separation and sensitive determination of o-, m-, and p-aminobenzoic acid isomers was achieved by combining open-tubular columns for capillary electrochromatography (OT-CEC) and online sample stacking. In this study, spherical gold nanoparticles were modified by a covalent attachment of mono-6-thio-β-cyclodextrin, and OT-CEC was formed by immobilizing cyclodextrin-modified gold nanoparticles (CD-AuNP) on prederivatized 3-mercaptopropyl-trimethoxysilane fused-silica capillaries. Based on the theory of moving chemical reaction boundary, effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were optimized. The optimized separations were carried out in 58 mmol/L HAc buffer at pH 3.0 using a capillary coated with CD-AuNP, while the optimized concentration was carried out in 50 mmol/L disodium hydrogen phosphate (pH 9.5). The linear ranges for m-, p-, and o-aminobenzoic acid were from 5.0 × 10⁻⁴–0.1, 5.0 × 10⁻⁴–0.1 and 1.0 × 10⁻⁴–0.1 mmol/L, respectively. And the detection limits (S/N = 3) were as low as 8.22 × 10⁻⁵, 8.21 × 10⁻⁵, and 3.76 × 10⁻⁵ mmol/L for m-, p-, and o-aminobenzoic acid, respectively. The run-to-run, day-to-day, and column-to-column reproducibilities of migration time were satisfactory with relative standard deviation values of less than 4.5 % in all cases. This method was successfully used in determining procaine hydrochloride injection sample with recoveries in the range of 96.1–106.6 % and relative standard deviations less than 5.0 %.

     

肌肽类生物活性肽的毛细管电泳在线富集技术

建立了毛细管区带电泳(CZE)在线富集3种肌肽类活性肽(肌肽、鹅肌肽和高肌肽)的两种简便有效的方法。一种是大体积进样反向压力排除基体富集（LVSRP）技术,即通过流体动力学进样,在不改变电源极性的条件下,利用反向压力排除样品基体,电堆积富集后进行CZE分离;另一种是大体积进样电渗流排除基体富集（LVSEP）技术,即通过流体动力学进样,于运行缓冲液中加入溴化十六烷基三甲基铵(CTAB)动态修饰毛细管表面,通过电渗流排除样品基体,改变电源极性后进行CZE分离。与常规CZE相比,LVSRP技术和LVSEP技术使检测灵敏度提高了40~60倍。对影响两种富集过程的一些因素进行了研究,在最优富集条件下考察本方法的线性范围为0.080~5.0 μmol/L。对3种生物活性肽的检测限(S/N=3)分别为LVSRP 41~58 nmol/L,LVSEP 35~43 nmol/L。     

电堆集-非水毛细管电泳分离测定甘草次酸和阿魏酸的研究

建立了电堆集富集-非水毛细管电泳(NACE)同时分离测定甘草中甘草酸和阿魏酸的新方法.系统研究了电压、非水溶剂、乙酸钠浓度、氢氧化钠浓度、样品溶剂等因素对电堆集和分离效果的影响,确立了分离和富集的最佳条件.以甲醇-乙腈(体积比4 : 6)为非水介质,30 mmol·L-1乙酸钠-2.5 mmol·L-1氢氧化钠为背景电解质;分离电压-20 kV,检测波长254 nm.在优化条件下,甘草次酸在0.80 ～12.80 mg·L-1(r＝0.999 6),阿魏酸在0.77 ～45.60 mg·L-1(r＝0.999 6)质量浓度范围内线性关系良好,回收率分别为97% ～102%,98% ～102%;甘草次酸检出限为0.069 mg·L-1,阿魏酸检出限为0.087 mg·L-1,RSD均不大于4.6%.     

Electrochemical Determination of Salivary N‐Acetylneuraminic Acid by Miniaturized Capillary Electrophoresis Coupled with Sample Stacking

Due to their important biological role as markers for different pathologies, sialic acid (SA) analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometric detection (mini‐CE‐AD) was developed for the determination of N‐acetylneuraminic acid (NANA), which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β‐formyl pyruvic acid was derivatized with electroactive 2‐thiobarbituric acid (TBA) to form an electroactive NANA‐TBA adduct, which could be readily determined by mini‐CE‐AD. The limit of detection (LOD) of NANA‐TBA could achieve 0.50 µg/mL (1.6 µmol·L^?1, S/N=3) based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8% –109% with RSDs of 1.8% –3.9%. Due to its simple design and construction, low cost and portability, the mini‐CE‐AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.     

在线样品浓缩毛细管区带电泳分析毛发中的苯丙胺类毒品

建立了毛细管区带电泳(CZE)的在线场放大样品堆积(FASS)方法。采用含有40%乙烯乙二醇的100 mmol/L磷酸盐二元缓冲液(pH 2.5),80%异丙醇的0.1 mmol/L磷酸样品溶液,利用缓冲体系与样品溶液体系电导率的差异,在毛细管中浓缩样品组分,对苯丙胺、甲基苯丙胺、亚甲基二氧基苯丙胺(MDA)、亚甲基二氧基甲基苯丙胺(MDMA)4种毒品进行了分离和定量测定,检测的灵敏度提高约1000倍。对于标准品的检出限可达到0.06μg/L。当样品浓度高于5μg/L时,分析的相对标准偏差在10%范围之内;用该方法对添加毒品的毛发进行了提取和测定,可检测到的添加浓度为1μg/g毛发。该方法可用于生物检材中苯丙胺类毒品的检测。     

Simultaneous Enantioseparation and Rapid Determination of Atenolol and Amlodipine Besylate by Capillary Electrochromatography

Chromatographia - Simultaneous enantioseparation and rapid determination method of atenolol (AN) and amlodipine besylate (AMB) was firstly established using diphenylmethane...     

介孔碳/纳米金修饰电极同时测定多巴胺、抗坏血酸和尿酸

采用溶胶法制备了介孔碳/纳米金复合材料,并利用透射电子显微镜、扫描电子显微镜和X射线衍射仪进行了表征。将合成的复合材料修饰于玻碳电极表面,用循环伏安法同时测定多巴胺(DA)、抗坏血酸(AA)和尿酸(UA)。在pH 7.2磷酸盐缓冲溶液中,DA、AA和UA的氧化峰得到了很好的分离;和裸电极比,介孔碳/纳米金修饰电极对DA、AA和UA具有良好的电催化作用,DA、AA和UA的氧化峰的峰电流强度分别增加1.7,2.0,12倍,3种物质的浓度分别在0.20~45.8,4.0~792.0,0.06~166.0μmol·L-1范围内与其峰电流强度呈线性关系,检出限(3S/N)分别为0.075,7.5,0.021μmol·L-1。     

唾液中苯丙胺类毒品的毛细管区带电泳在线富集检测

采用毛细管区带电泳(CZE)中的场放大样品堆积(FASS)技术对唾液中的苯丙胺类毒品进行了检测.采用含30%(体积分数)甲醇的100mmol/L磷酸盐(pH3.0)为分离缓冲液,用水溶解样品,利用缓冲体系与样品溶液体系电导率的差异,在毛细管中浓缩样品组分,对苯丙胺(AM)、甲基苯丙胺(MAM)、3,4-(亚甲二氧基)苯丙胺(MDA)、3,4-(亚甲二氧基)甲基苯丙胺(MDMA)4种毒品进行了分离和定量测定.采用利多卡因为内标,对添加上述4种毒品的唾液进行液液提取并进行FASS-CZE检测,可检测到的上述毒品质量浓度为0.002mg/L,与常规毛细管区带电泳比较,灵敏度提高上千倍;相对标准偏差在1.4%～7.7%之间,回收率在74%～108%.该方法可用于生物检材中苯丙胺类毒品的检测.     

金纳米粒子修饰毛细管硅胶整体柱的制备及其电色谱性能研究

通过毛细管硅胶整体柱表面修饰十八烷基硫醇金纳米粒子,制备了一种新型毛细管电色谱固定相.制备金纳米粒子修饰整体柱时,采用溶胶-凝胶法制备毛细管硅胶整体柱,并在其表面化学修饰3-巯基丙基三甲氧基硅烷;通过巯基基团固载金纳米粒子于整体柱上,再共价键合十八烷基硫醇于金纳米粒子表面.以甲苯为探针,对理论塔板高度与流动相线速度之间...     

采用毛细管电泳电堆集富集技术分离与测定雪样中的痕量阳离子

以咪唑为背景电解质,以α－羟基异丁酸和１８－冠醚－６为络合剂,采用毛细管离子电泳间接紫外法,研究了发样中痕量ＮＨ４＾＋、Ｋ＾＋、Ｃａ＾＋、Ｍｇ＾２＋分离与测定的方法。通过向缓冲液中加入甲醇,使Ｃａ＾２＋、Ｎａ＾＋迁移顺序发生反转,有利于在Ｃａ＾２＋的浓度较高时少量Ｎａ＾＋的测定。采用电堆集富集技术,各离子的检测限达１×１０＾－７ｍｏｌ／Ｌ。以Ｌｉ＾＋作为内标,采用标准加入法对地样中的痕量阳离子进行     

Separation of 5-Lipoxygenase Metabolites Using Cyclodextrin-Modified Microemulsion Electrokinetic Chromatography and Head Column Field-Amplified Sample Stacking

A cyclodextrin-modified microemulsion electrokinetic chromatography method employing head column field-amplified sample stacking was developed for the analysis of arachidonic acid metabolites of the lipoxygenase pathways. The influence of the concentration of boric acid, the surfactant sodium dodecyl sulfate, the co-surfactant 1-butanol and the oil phase octane as well as the pH of the background electrolyte, the separation voltage and the separation temperature was studied. The optimized microemulsion consisting of 20 mM boric acid buffer, pH 9.0, 3.0 % (m/v) sodium dodecyl sulfate, 0.5 % (v/v) octane, 5.0 % (v/v) 1-butanol and 15 mM α-cyclodextrin enabled the separation of 20-hydroxy-leukotriene B₄, leukotriene B₄, 6-trans-leukotriene B₄, 6-trans-12-epi-leukotriene B₄, 5(S)-hydroxy-6-trans-8,11,14-cis-eicosatetraenoic acid, 12(S)-hydroxy-5,8,14-cis-10-trans-eicosatetraenoic acid, 15(S)-hydroxy-5,8,11-cis-13-trans-eicosatetraenoic acid as well as the internal standard prostaglandin B₁ in <10 min employing a separation voltage of 17.5 kV at a temperature of 23 °C. A matrix peak from solid-phase extraction sample workup co-migrated with 5(S)-hydroxy-6-trans-8,11,14-cis-eicosatetraenoic acid affecting peak integration. The addition of 5 % (v/v) 2-propanol to the microemulsion resulted in the separation of this eicosatetraenoic acid and the matrix components at the expense of analysis time and peak resolution between the diastereomers 6-trans-leukotriene B₄ and 6-trans-12-epi-leukotriene B₄. In summary, the MEEKC method appeared to be especially suitable for the more polar arachidonic acid metabolites.     

毛细管区带电泳同时分离苯二酚和硝基苯酚位置异构体

运用毛细管区带电泳模式,通过在缓冲溶液中添加有机溶剂成功地分离了邻、间、对苯二酚和邻、间、对硝基苯酚两组位置异构体。研究了缓冲溶液种类、浓度、pH值、电泳电压、温度、进样时间及有机溶剂等因素对分离的影响,得出了6种样品的标准曲线、线性范围及加样回收率。在优化条件下,10min内实现了上述6种酚类化合物的分离。该方法简便、快速、重现性好。     

长光路光度法测定痕量金

本文研究了用长光路光度法测定痕量金,采用410~#哌啶树脂富集,分离,基于溴金酸与乙基罗丹明B形成红色离子缔合物可萃取于苯中比色。该法具有高灵敏度和高稳定性。测定金的线性范围为2～60ng/ml,试用于金含量为0.46Pg/g的矿样。相对标准编差小于12.5％。     

羟基苯甲酸异构体的毛细管区带电泳分离及阿司匹林片剂中邻羟基苯甲酸的测定

1引言邻羟基苯甲酸主要用于医药工业合成阿司匹林。我国药典(2005版)规定片剂中的含量不能超过0.3%。本实验以阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)作电渗流改性剂,乙腈作有机添加剂,利用毛细管区带电泳-二极管阵列检测器技术实现了邻羟基苯甲酸与间羟基苯甲酸和对羟基     

Molecularly Imprinted Polymer Monolithic Column Separation of Isomers and Analogues of Vanillin by Capillary Electrochromatography

A vanillin imprinted capillary monolithic column was synthesized by in situ polymerization reaction using ethylene-glycol dimethacrylate as cross-linking monomer and methacrylic acid as functional monomer. Under the optimum conditions of capillary electrochromatography, this molecularly imprinted polymer （MIP）-based column showed high selectivity and could recognize not only template molecule vanillin but also positional isomer o-vanillin from their structural analogues.     

场增强样品堆积-毛细管电泳法测定山楂粉中的氨基酸

采用场增强样品堆积-毛细管电泳法建立了在线富集氨基酸的分析方法,用于中药山楂中水解氨基酸的检测,并进行了回收率实验. 采用富集电压为-20 kV,进样压力为3 psi,进样时间为50 s,紫外检测波长为214 nm,运行缓冲溶液为270 mmol/L乙酸-270 mmol/L乙酸钠（pH=4.15）-6%（V/V）乙腈溶液,分离电压为17 kV,组氨酸、精氨酸、色氨酸、酪氨酸、缬氨酸、苯丙氨酸、亮氨酸、苏氨酸、丙氨酸、甘氨酸、谷氨酸和门冬氨酸等12种氨基酸在50 min内达到分离,检出限在0.000 3~0.08 μg/mL之间.