毛细管区带电泳电化学检测法测定药物及果汁中芦丁和L-抗坏血酸

用毛细管区带电泳-电化学检测法同时测定复方芦丁片及果汁中芦丁和L-抗坏血酸的含量.研究了电极电位、电解液浓度和酸度、电泳电压及进样时间等对电泳的影响,得到了较为优化的测定条件.以直径为300μm的碳圆盘电极为检测电极,电极电位为1.0V(vs.SCE),在25mmol/L硼砂-50mmol/LNaH₂PO₄(pH8.0)运行缓冲液中,上述两组分在12min内完全分离.芦丁和L-抗坏血酸浓度分别在1.0×10^-6～2.5×10^-4和5.0×10^-6～2.5×10^-3mol/L范围内与电泳峰电流呈现良好线性关系,检测下限分别为8.0×10^-7和3.3×10^-6mol/L.9次测定含5.0×10^-5mol/L芦丁和2.5×10^-4mol/LL-抗坏血酸的试样溶液,峰高的相对标准偏差分别为2.85%和1.65%,5次测得的平均回收率分别为97.73%和99.68%.     

胶束电动毛细管色谱安培检测中药马齿苋中多巴胺和去甲肾上腺素

建立了胶束电动毛细管色谱结合电化学安培检测同时分析中药马齿苋中多巴胺和去甲肾上腺素的方法。考察了缓冲液的浓度、pH值、十二烷基硫酸钠(SDS)浓度以及工作电极电势对分离检测的影响。在优化的条件下,多巴胺和去甲肾上腺素在1.0×10-6～5 0×10-4mol/L范围内有良好线性,浓度检测限(S/N=3)分别为8 7×10-7mol/L和4 2×10-7mol/L,质量检测限分别为1 45fmol和0 41fmol。该方法组分定性可靠,不需要衍生处理,选择性好。将该法应用于中药马齿苋样品的分析,获得了较好的结果。     

毛细管胶束电动色谱法分离测定中药半枝莲中的7种有效成分

建立了毛细管胶束电动色谱同时分析检测中药半枝莲药材及其膏剂中黄芩素、柚皮素、汉黄芩素、野黄芩苷、芹菜素、木犀草素和原儿茶酸7种有效成分的方法。半枝莲样品中7种有效成分经甲醇超声提取。实验考察了运行缓冲溶液的pH值和浓度、添加剂、检测波长、分离电压和进样时间等重要参数对目标物分离的影响。得到的优化条件为: 运行缓冲液50 mmol/L硼砂-0.20 mol/L硼酸溶液(pH 8.4),含8.5 mmol/L十二烷基硫酸钠(SDS),分离电压25 kV,检测波长260 nm和335 nm。在此条件下,7种组分于12 min内达到基线分离。各组分在8×10~6～3.2×10~4mol/L范围内呈良好的线性关系,相关系数(r2)为0.9965～0.9999;检出限为7.0×10~8～2.0×10~6mol/L;回收率均大于85%。该方法提取简便、准确可靠、重复性好、灵敏度高,可以用于中药半枝莲中7种有效成分的定量检测。     

Determination of antioxidants in cosmetics by micellar electrokinetic capillary chromatography with electrochemical detection

A new and efficient method for the determination of antioxidants [Propyl gallate (PG), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT)] in cosmetics has been established by using micellar electrokinetic capillary chromatography with electrochemical detection (MECC-ED). Under the optimum conditions of the method, all analytes were successfully separated within 13 min at the separation voltage of 18 kV in a 20 mmol/L borate running buffer (pH 7.4) containing 25 mmol/L sodium dodecyl sulfate. The excellent linearity was obtained in the concentration range from 5.0 x 10(-4) to 2.0 x 10(-6) mol/L and the detection limits (S/N = 3) of PG, TBHQ, BHA, and BHT range from 3 x 10(-7) to 3 x 10(-6) mol/L.     

Determination of fumaric and maleic acids with stacking analytes by transient moving chemical reaction boundary method in capillary electrophoresis

The paper presents an on-line transient moving chemical reaction boundary (MCRB) method for simply but efficiently stacking analytes in capillary electrophoresis (CE). The CE technique was developed for a rapid determination of fumaric and maleic acid. Based on the theory of MCRB, Effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were investigated to acquire the optimum conditions. The optimized separations were carried out in a 20 mmol/L sulphate neutralized with ethylenediamine to pH 6.0 electrolytes using a capillary coated with poly (diallyldimethylammonium chloride) and direct UV detection at 214 nm. The optimized preconcentrations were carried out in 50 mmol/L borax (pH 9.0). The calibration curves were linear in the concentration range of 1.0 × 10⁻⁷–1.0 × 10⁻⁴ mol/L and 5.0 × 10⁻⁷–1.0 × 10⁻⁴ mol/L for fumaric and maleic acid with correlation coefficients higher than 0.9991. The detection limits were 5.34 × 10⁻⁸ mol/L for fumaric acid and 1.92 × 10⁻⁷ mol/L for maleic acid. This method was applied for determination of fumaric acid in apple juice and of fumaric and maleic acid in dl-malic, the recovery tests established for real samples were within the range 95–105%. This work provided a valid and simple approach to detect fumaric and maleic acid.     

木犀草素在离子液体修饰电极上的电催化氧化及其测定

用1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF₆)疏水性离子液体修饰玻碳电极,在0.2 mol/L磷酸盐缓冲溶液(pH为4.0～8.0)中,运用循环伏安法（CV）和差示脉冲溶出伏安法(DPSV)研究了木犀草素在修饰电极上的电化学行为,建立了测定木犀草素含量的新方法。 实验结果表明,该修饰电极上木犀草素氧化、还原峰电位均负移,峰电流增大。 在-0.2～0.7 V电位区间,pH=7.0的磷酸盐缓冲溶液体系中,木犀草素在修饰电极表面发生的是受吸附控制的准可逆等电子等质子电极反应,电子转移系数α=0.5,吸附量为4.6×10-10 mol/cm²;木犀草素氧化峰电流与其浓度在1.0×10^-10～1.6×10^-8 mol/L范围内呈良好的线性关系,检出限达到3.2×10^-11 mol/L,回收率为98.7%～102.0%;该法操作简单、快速、灵敏、准确;可用于野菊花中类黄酮的测定。     

毛细管电泳高频电导法快速分离检测混合氨基酸

氨基酸(Am ino acids,AA s)是组成生物大分子的基本单元,与人的健康状况有极其密切的关系.在医学和生命科学研究中,微量氨基酸的分离检测具有重要意义.     

毛细管电泳电化学检测法测定红葡萄酒中的多元酚

目前 ,人类各种疾病约 89%起因于活性氧 .因此消除活性氧基团 ,使过氧化物对机体的损伤降到最低限度已成为研究的热点 [1] . Maxwell等 [2 ] 测试了红葡萄酒在人体血液中的抗氧化能力 .发现从刚喝下红葡萄酒时起 ,抗氧化活性就开始上升 ,90 min后达到最大 ,抗氧化活性平均上升约 1 5 % .葡萄酒中的多酚含量与活性氧消除能力的相关系数高达 0 .9686,所以确立葡萄酒中多元酚的分析方法有重要意义 .红葡萄酒中含有酚酸类、儿茶素类、黄酮类等多酚类化合物 ,通常采用气相色谱[3] 、高效液相色谱 [4 ] 测定 .毛细管电泳 ( CE)应用于葡萄酒中多…     

基于拮抗作用检测除草剂的类囊体膜生物传感器研究

利用除草剂对植物类囊体束缚酶分解过氧化氢的拮抗作用,研制了一种快速检测痕量除草剂的电化学生物传感器.将植物类囊体用聚乙烯醇-苯乙烯吡啶(PVA-SbQ)光敏聚合剂在紫外光诱导下产生大分子网状结构进行包埋,制成生物敏感膜,并固定在铂电极表面.根据加入除草剂时类囊体膜束缚酶分解过氧化氢活性的变化,对除草剂进行测定.在含有1×10^-3mol/LNaCl,5×10^-3mol/LMgCl₂和0.01mol/LH₂O₂的Tris-HCl缓冲溶液(pH=7.4)中,基于测量0.65V处H₂O₂氧化电流的变化,可以对下列浓度的除草剂进行定量检测:百草枯3×10^-9～1.5×10^-7mol/L,敌草龙1×10^-8～3×10^-7mol/L,扑草净4×10^-8～3×10^-6mol/L,阿特拉津1×10^-7～5×10^-6mol/L,莠灭净1×10^-7～5×10^-6mol/L.利用PVA-SbQ光聚合膜固定类囊体,能够使酶的活性在低温下保持数月.     

胶束毛细管电动色谱法用于DNA碱基腺嘌呤和嘌呤类抗癌药物的研究

腺嘌呤（ADE）是存在于自然界的DNA碱基之一,8-羟基嘌呤（8-HP）是DNA中氧化损伤产物,6-巯基嘌呤（6-MCP）和8-氮杂鸟嘌呤（8-AZN）都属于核酸代谢拮抗药物,该药主要用于治疗急性白血病,对慢性颗粒细胞白血病及其它多种肿瘤也较有效,能在一个体系里同时检测正常DNA碱基、DNA中氧化损伤产物和抑制DNA损伤的抗癌药物,     

Determination of hesperidin and synephrine in Pericarpium Citri Reticulatae by capillary electrophoresis with electrochemical detection

A method based on capillary electrophoresis with electrochemical detection (CE-ED) has been developed for the determination of hesperidin (HP) and synephrine (SP) in the Chinese traditional herbal drug, Pericarpium Citri Reticulatae, the dried rind of the ripe fruits of Citrus reticulata Blanco (mandarin orange). The effects of some important factors such as the acidity and concentration of running buffer, separation voltage, and detection potential were investigated to determine the optimum conditions. The working electrode was a 300 microm diameter carbon disc electrode positioned opposite the outlet of the capillary. Both analytes could be well separated within 5 min in a 40 cm long capillary at a separation voltage of 12 kV in 50 mmol L(-1) borate buffer (pH 9.0). Excellent linearity was observed for the dependence of peak current on analyte concentration in the range from 2.5 x 10(-6) to 1.0 x 10(-3) mol L(-1) for SP and from 5.0 x 10(-6) to 1.0 x 10(-3) mol L(-1) for HP. The detection limits (S/N=3) for SP and HP were 4.96 x 10(-7) mol L(-1) and 6.54 x 10(-7) mol L(-1), respectively. This method has been successfully applied for the analysis of real samples, with satisfactory results.     

磺胺类人工合成甜味剂的毛细管电泳/电导法分离检测

采用15 mmol/L Tris-10 mmol/L H3BO3-0.2 mmol/L EDTA为电泳运行液,0.2%四乙烯五胺为电渗流抑制剂,融硅石英毛细管(45 cm×50 μm),负高压分离(-15 kV),柱端接触式电导检测,建立了磺胺类人工合成甜味剂(糖精钠、安赛蜜、甜蜜素)的高效毛细管电泳/电导法分离检测方法.糖精钠、安赛蜜、甜蜜素的线性检测范围分别为0.8 ～120、1.1 ～120、1.5 ～120 μmol/L,检出限分别为0.3、0.4、0.6 μmol/L.详细讨论了电泳运行液的组成、浓度以及进样方式对灵敏度和分离度的影响.该法用于市售饮料中3种甜味剂的分离检测,结果满意.     

黄芩及其制剂中黄芩素和黄芩甙的

用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7～1.0×10 -3mol/L和1.0×10 -6～1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。     

Determination of Nicotine in Tobacco by Capillary Electrophoresis with Electrochemical Detection

A sensitive, simple and low-cost method based on capillary electrophoresis(CE) with electrochemical(EC) detection at a carbon fiber microdisk electrode(CFE) was developed for the determination of nicotine. Effects of detection potential, concentration and pH value of the phosphate buffer, and injection time as well as separation voltage were investigated. Under the optimized conditions: a detection potential of 1.20 V, 40 mmol/L phosphate buffer(pH 2.0), a sample injection time of 10 s at 10 kV and a separation voltage of 16 kV, the linear range obtained was from 5.0×10^-7 mol/L to 1.0×10^-4 mol/L with a correlation coefficient of 0.9989 and the limit of detection(LOD, S/N=3) obtained was 5.0×10^-8 mol/L. The method was also used to determine the nicotine in cigarettes. Nicotine amount ranged from 0.211 mg/g to 0.583 mg/g in the pipe tobacco of seven brands of cigarette and the amount in one cigarette varied from 0.136 mg/cigarette to 0.428 mg/cigarette.     

Determination of bavachin and isobavachalcone in Fructus Psoraleae by high-performance liquid chromatography with electrochemical detection

A simple, sensitive and selective method of high-performance liquid chromatography with electrochemical detection (HPLC-ECD) has been developed for simultaneous determination of bavachin and isobavachalcone in Fructus Psoraleae. At optimized conditions, bavachin and isobavachalcone could be well separated within 15 min at a detection potential of +0.80 V with 0.03 mol/L acetate buffer solution (pH 5.17)/acetonitrile (2:3, v/v) as the mobile phase. The relationships between peak areas and concentrations were linear from 8.26 × 10(-7) to 1.21 × 10(-4) mol/L for bavachin, and from 1.01 × 10(-8) to 1.61 × 10(-4) mol/L for isobavachalcone, respectively. The method offered excellent linearity with regression coefficient R(2) >0.995. The method presented detection limits (S/N = 3) of 8.81 × 10(-9) mol/L for bavachin and 1.17 × 10(-10) mol/L for isobavachalcone. It indicates that the sensitivity of electrochemical detection is ten times higher than that of diode array detection (DAD). The mean recoveries around 98% with a relative standard deviation less than 3.1% for the two analytes have been obtained. The proposed separation and detection procedures were successfully applied to the simultaneous determination of bavachin and isobavachalcone in traditional Chinese medicine.     

基于复合膜修饰玻碳电极对黄嘌呤的选择性测定

制备了一种新型电化学传感器--聚2,2-联吡啶(Pbpy)/1-苯基-3-甲基-4-(α-呋喃甲酰基)-5-吡唑啉酮(HPM-α-FP)/玻碳(GC)复合膜修饰电极。 运用循环伏安法和脉冲伏安法研究了药物分子黄嘌呤(XN)的电化学行为及反应机理。 与裸GCE和Pbpy/GCE电极相比,复合修饰电极Pbpy/HPM-α-FP/GCE测定XN的氧化峰电流和检测灵敏度均有显著提高,表明聚2,2-联吡啶与酰基吡唑啉酮产生了协同增效作用。 当pH=8,扫速为100 mV/s的条件下,氧化峰电流与黄嘌呤浓度在6×10-7～1×10-5 mol/L和1×10-5～1×10-4 mol/L之间均呈现良好的线性关系,检出限为1×10-8 mol/L。 该修饰电极可用于共存尿酸(UA)、抗坏血酸(AA)体系及实际样品的黄嘌呤含量测定。     

花旗松素与牛血清白蛋白相互作用的光谱和电化学

采用紫外光谱法、荧光光谱法和循环伏安法,研究了牛血清白蛋白(BSA)与花旗松素（taxifolin）的相互作用。 用荧光法和循环伏安法测得花旗松素与BSA的结合常数K分别为1.3×106和1.6×106 L/mol,结合位点数均接近1.3。花旗松素对牛血清白蛋白是静态猝灭。BSA荧光强度的降低与花旗松素浓度在一定范围内呈线性关系,其线性范围为6.00×10-7~2.00×10-5 mol/L,检出限为2.00×10-7 mol/L。花旗松素氧化峰电流的下降与BSA浓度在一定范围内呈线性关系,其线性范围为7.00×10-7~1.00×10-4 mol/L,检出限为3.00×10-7 mol/L。用于合成样品中花旗松素和BSA的测定,结果满意。     

Simultaneous determination of flavonoids in chrysanthemum by capillary zone electrophoresis with running buffer modifiers

Despite the separation efficiency of capillary electrophoresis (CE) is much higher than other chromatographic methods, it is sometimes difficult to perfectly separate the complex ingredients in biological samples. One possible and simple way to develop the separation effect in CE is to add some modifiers in the running buffer. In this paper, the suitable running buffer modifiers were explored to simultaneously separate and detect six typical flavonoids (apigenin, luteolin, kaempferol, quercetin, (+)-catechin and (−)-epicatechin) which are the main active ingredients in chrysanthemum by capillary zone electrophoresis with amperometric detection (CZE-AD). It was found that when β-cyclodextrin (β-CD) and the mixture of methanol and ethanol were used as running buffer modifiers, a baseline separation of the six analytes could be accomplished in less than 20 min and the detection limits were as low as 10⁻⁷ or 10⁻⁸ g ml⁻¹. Other factors affecting the CZE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage and sample injection time were extensively investigated. Under the optimum conditions, a successful practical application on the determination of chrysanthemum samples confirmed the validity and practicability of this method.     

壳聚糖与茜素红相互作用的电化学研究

生物活性大分子蛋白质、DNA及多糖等与小分子探针间的相互作用及其机理是近年来化学、临床医学及生命科学中研究的热点之一,这些研究可用于生物大分子的检测和新药的研发,壳聚糖(CS)是目前自然界已被发现的唯一带正电荷的可食用的碱性多糖,分子中含有丰富的氨基和羟基,并具有双螺旋结构,近年来已在食品、医药保健、化妆、环保、农业及化学化工等领域得到广泛应用,     

食品中柠檬黄铝色淀和日落黄铝色淀的毛细管区带电泳分析

发展了一种新的采用毛细管区带电泳分析柠檬黄铝色淀和日落黄铝色淀的方法。通过前处理步骤成功实现了铝色淀中铝基质与色素的分离。利用石英毛细管柱（48.50 cm（有效长度40.00 cm）×50 μm）,分别针对柠檬黄铝色淀和日落黄铝色淀进行了电泳条件的优化,并得到最优分离结果。所建立的定量分析方法的检出限对于柠檬黄铝色淀和日落黄铝色淀分别达0.26 mg/L和0.27 mg/L,线性范围分别为0.53~1.3×10²mg/L和0.54~1.4×10²mg/L,两种被分析物的测定重复性（RSD,n=6）分别为4.3%和5.7%,日间重复性（RSD,n=6）分别为5.6%和6.0%。经过更深入研究后,该方法可以发展为食品中相应色淀的检测方法。