在线富集-胶束电动毛细管色谱用于烷基酚类物质的检测

以胶束电动毛细管色谱(Micellar electrokinetic capillary chromatography,MEKC)分离邻仲丁基苯酚(os BP)、双酚A(BPA)、四溴双酚A(TBBPA)、辛基酚(OP)和壬基酚(NP)。采用反向极性堆积模式(Reversed electrode polarity stacking mode,REPSM)建立了在线富集5种烷基酚类物质的简便、有效方法。与常规MEKC方法相比,REPSM方法使5种烷基酚类物质的灵敏度提高了20~285倍。考察了常规MEKC的分离条件,并对影响富集过程的一些因素进行了研究,同时对富集方法的重现性和检出限进行了考察。结果表明,REPSM对5种烷基酚类物质的检出限(S/N=3)为0.027~0.64μmol/L。该方法已成功应用于食品塑料盒中烷基酚类物质的测定,加标回收率为86.0%~103%。     

气相色谱-质谱法同时测定保鲜膜包装食品中15种邻苯二甲酸酯

以常见的保鲜膜包装食品为考察对象,研究了不同时间保鲜膜中邻苯二甲酸酯类化合物(PAEs)在食品中的迁移情况;建立了15种邻苯二甲酸酯(PAEs)的气相色谱-电子轰击离子源质谱(GC-EI/MS)测定方法。结果表明:该方法具有良好的线性关系,相关系数不低于0.9991,加标回收率为85%～105%,相对标准偏差在5.1%～9.5%,15种邻苯二甲酸酯(PAEs)的检出限为0.010～0.045μg.kg-1。该方法具有简单、快速、灵敏度高和定性定量准确等优点,满足实际样品的分析要求。     

气相色谱-质谱法测定水产品中24种邻苯二甲酸酯类化合物

建立了同时测定水产品中24种邻苯二甲酸酯类化合物(PAEs)的气相色谱-质谱(GC-MS)分析方法。称取1.0 g样品于10 mL玻璃离心管中,加内标D4-DEHP溶液(10 mg/L)100μL,氯化钠0.5 g,以5 mL乙腈-乙酸乙酯(1∶1)超声提取5 min,4 000 r/min离心5 min,移取上层有机相。再加入3 mL乙腈-乙酸乙酯重复提取。合并两次的提取液浓缩至1～2 mL后,经Florisil玻璃固相萃取柱净化,洗脱液在50℃下氮吹至近干,用正己烷超声溶解定容至1 mL,供GC-MS分析。24种PAEs的定量下限(LOQ)为1～500μg/kg,检出限(LOD)为0.1～100μg/kg。选取鱼、虾为研究基质考察方法的准确度及精密度,24种PAEs在3个添加水平时的平均回收率及相对标准偏差(n=6)分别为73%～120%、2.0%～19.7%。结果表明,该方法提取效率高,净化效果好,重复性强,能够满足水产品中邻苯二甲酸酯类化合物的检测需求。     

柱前衍生/气相色谱-质谱法同时测定水中壬基酚和邻苯二甲酸酯

在采用OasisHLB固相萃取柱富集水中壬基酚和邻苯二甲酸酯的基础上 ,利用壬基酚与N,O_双 (三甲基硅烷基 )三氟乙酰胺 (BSTFA)之间的衍生化反应 ,发展了气相色谱 -质谱同时测定水中壬基酚和邻苯二甲酸酯类化合物的方法 ,能够准确测定11种壬基酚同分异构体及4种邻苯二甲酸酯 ,回收率达到78.9 %±24.5 % ;具有较高的灵敏度 ,方法检出限达到(1.9～5.5)×10-4μg/L;并且具有很好的重现性和精密度。该方法已成功应用于城市污水中壬基酚和邻苯二甲酸酯类内分泌干扰物的分析测定     

固相微萃取-气相色谱法测定白洋淀水样中的邻苯二甲酸酯类化合物

建立了固相微萃取(SPME)-气相色谱法(GC)分析环境水样中痕量邻苯二甲酸酯类化合物(PAEs)的方法。选用100 μm聚二甲基硅烷(PDMS)萃取纤维,在磁力搅拌条件下,对水样中的PAEs萃取富集60 min,然后直接注入GC进样口,在250 ℃温度下解吸4 min后进行分析测定,13种PAEs能得到充分提取和分离。方法的重现性(以相对标准偏差(RSD)计为0.2%～9.7%,检出限为0.02～0.83 μg/L。将本方法应用于白洋淀水样中PAEs的分析检测发现,样品中邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)检出率相对较高。对水样进行两个浓度水平(2.5 μg/L和5.0 μg/L)的加标试验,加标回收率为75.3%～111.0%,RSD为2.1%～8.0%(n=3),能够满足环境水样中痕量PAEs的测定要求。     

基于聚苯乙烯纳米磁性材料的基质分散-固相萃取/液相色谱法测定白酒中的邻苯二甲酸酯

建立了一种快速、高效、灵敏的基质分散-磁性固相萃取/液相色谱(dMSPE/HPLC)方法,用于测定白酒中6种邻苯二甲酸酯类化合物(PAEs)残留量。样品用聚苯乙烯纳米磁性高分子材料进行富集处理后,经C8反相液相色谱柱(250 mm×4.6 mm×5μm)分离,以甲醇-水为流动相,梯度洗脱,230 nm检测。重点考察了样品p H值、吸附时间和洗脱剂的种类与用量等对PAEs富集回收率的影响。结果表明,在最佳实验条件下,6种PAEs在2~500 ng/L浓度范围内呈良好的线性关系,相关系数(r2)均不小于0.997 9;平均回收率为85.2%~101.2%,相对标准偏差(RSDs)为0.8%~9.2%;检出限(LODs)为0.22~4.5 ng/L,定量下限(LOQs)为1.2~10 ng/L。方法可用于白酒中PAEs的快速筛查和确证分析。     

酞酸酯的场增强样品进样-微乳液毛细管电动色谱分析

建立了场增强样品进样–微乳液毛细管电动色谱(microemulsion electrokinetic chromatography,MEEKC)分析6种酞酸酯的方法,对影响富集过程的因素进行了考察。最佳富集条件为:以压力进样先进一段水柱(5.52 kPa×500s),在富集电压为-15 kV下,样品以电动方式进样富集,样品基质为30mmol/L胆酸钠+30.0 mmol/L硼砂(pH 8.5)。与常规MEEKC方法相比,场增强样品进样在线富集技术使6种酞酸酯的检测灵敏度提高了1.6～1000倍,检测限(S/N=3)为1～500 ng/mL。所建立的方法用于食品塑料袋中酞酸酯的测定,加标回收率为92.5%～112.2%。     

气相色谱-质谱法测定白酒中邻苯二甲酸酯

建立了白酒中15种邻苯二甲酸酯类化合物(PAEs)残留量的气相色谱-电子轰击离子源质谱(GC-EI/MS)测定方法。样品通过旋转蒸发除乙醇,正己烷超声提取,LC-Si SPE小柱净化,氮吹浓缩后进行气相色谱-质谱法分析。结果表明:该方法具有良好的线性关系,相关系数(r2)大于0.998,平均加标回收率为85.3%~103.1%,相对标准偏差为3.8%~8.8%,15种邻苯二甲酸酯(PAEs)的方法检出限(MDL)为0.011~0.041mg/L。该方法具有简单、快速、灵敏度高和定性定量准确等优点,满足各类白酒样品的分析要求。     

基于四通道色谱分离仪净化-GC-MS法测定土壤中邻苯二甲酸酯类残留

建立了四通道色谱分离仪净化-气相色谱-质谱(GC-MS)法同时检测土壤中6种邻苯二甲酸酯(PAEs)类化合物的分析方法。样品经正己烷-丙酮(1:1,V:V)超声提取、四通道色谱分离仪净化(以正己烷-丙酮(1:1,V:V)洗脱)、GC-MS选择SIM模式测定。结果表明:6种PAEs类化合物在0.02~10 mg/L范围内定量离子的峰面积与质量浓度具有良好的线性关系(r0.9988),仪器检出限(LOD)为0.51~3.52μg/L,在3个浓度水平的加标回收率为83.7%~108.8%,相对标准偏差(RSD)为3.4%~11%。该方法可满足土壤中邻苯二甲酸酯类残留物的分析检测。     

超声辅助分散液液微萃取-高效液相色谱测定水样中的4种邻苯二甲酸酯类增塑剂

建立了采用超声辅助分散液液微萃取技术结合高效液相色谱法(UA-DLLME-HPLC)对4种邻苯二甲酸酯(PAEs)进行富集、检测的方法,并成功应用于实际水样分析。实验中采用富集因子来评价萃取效率,考察并优化了影响萃取效率的主要因素,包括萃取剂类型和用量、分散剂类型和用量、超声时间、离子强度、萃取时间和pH值等。结果表明: 在最佳萃取条件下,该法对4种PAEs（邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯和邻苯二甲酸二正辛酯）具有较高的富集能力,富集因子分别为71、144、169和159;检出限分别为3.78、1.77、3.07和3.30 μg/L。对实验室自来水、某品牌矿泉水以及湖水分别加标50、200及500 μg/L的回收率为82.99%～114.47%,相对标准偏差为1.93%～8.31%。该法简便、快速、环保,可以用于测定实际水样中的PAEs类增塑剂。     

Strategies for Analyzing Cephalosporins by Microemulsion Electrokinetic Chromatography

We studied microemulsion electrokinetic chromatography (MEEKC) for the analysis of cefazolin, cefoperazone and cephalexin. We compared the separation of the cephalosporins obtained by MEEKC at a high pH and at a low pH. Good separations of the compounds were achieved within 9 min by both methods. To reduce the analysis time, we used the "short-end" injection technique. We also present two on-line preconcentrations of the analytes by sample stacking, reversed electrode polarity stacking mode (REPSM) (at high-pH) and stacking with reverse migrating pseudostationary phase (SRMP) (at low-pH). We also report parameters for validation such as linearity and limit of detection. Our results show that the developed methods are suitable for analyzing these three cephalosporins.     

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。     

Separation and on-column preconcentration of some nonsteroidal anti-inflammatory drugs by microemulsion electrokinetic capillary chromatography using high-speed separations

Various strategies have been investigated for separating a group of nonsteroidal anti-inflammatory drugs (NSAIDs) by microemulsion electrokinetic capillary chromatography (MEEKC) using high-speed separations. The parameters that of affect the separation, such as the nature of the oil droplet and the buffer, and the surfactant concentration have been studied. In addition, several organic solvents were used to decrease the retention of the analytes in the oil droplet phase and to improve the resolution of the NSAIDs. The optimum microemulsion background electrolyte (BGE) solution made of 0.8% w/w ethyl acetate, 6.6% w/w butan-1-ol, 6.0% w/w acetonitrile, 1.0% w/w sodium dodecyl sulfate (SDS), and 85.6% w/w of 10 mM sodium tetraborate at pH 9.2 resolved the drugs within 8 min. The short-end injection procedure is an alternative for reducing the analysis time. When this procedure was used, the microemulsion BGE solution consisted of 0.8% w/w ethyl acetate, 6.6% w/w butan-1-ol, 17.0% w/w methanol, 1.0% w/w SDS, and 74.6% w/w of 10 mM sodium tetraborate, pH 9.2, and the NSAIDs were separated within 3 min. The reversed electrode polarity stacking mode (REPSM) technique was applied to the on-line concentration of the NSAIDs. In this technique, the sample matrix was pumped out of the capillary using a polarity-switching step. When this technique was applied, the sensitivity was enhanced up to 40-fold and the limits of detection (LODs) were in the low microg.L(-1) levels.     

毛细管电泳中移动反应界面法富集和检测尿样中的氧化苦参碱

采用建立在移动反应界面理论上的体系进行尿样中氧化苦参碱的富集与定量检测。与传统的毛细管电泳相比,体系中引入了富集缓冲溶液(富集相)和分离缓冲溶液(分离相)。优化的条件如下:样品缓冲溶液为20 mmol/L 甲酸钠(用氨水调节pH至10.70),富集缓冲溶液为40 mmol/L 甲酸-甲酸钠(pH 2.60),分离缓冲溶液为100 mmol/L 甲酸-甲酸钠(pH 4.80);样品相压力进样1.4 kPa×3 min,富集相压力进样1.4 kPa×7 min,紫外检测波长210 nm,电压21 kV。氧化苦参碱在2.2~65 mg/L的质量浓度范围内呈良好的线性关系(r=0.9991),检出限为0.74 mg/L,灵敏度比常规毛细管电泳方法提高约70倍,重现性良好。该方法已经成功地应用于尿样中氧化苦参碱的检测。     

毛细管电泳-场强放大样品堆积法检测染发剂中的7种苯胺类物质

建立了毛细管电泳-场强放大样品堆积测定染发剂中4,4′-二氨基二苯甲烷、苯胺、邻甲氧基苯胺、对氨基苯甲醚、3,4-二甲基苯胺、间氨基苯酚、1-萘胺7种苯胺类物质的分析方法。在优化的缓冲溶液体系(0.15 mol/L NaH2PO4,0.015 mol/L 三乙醇胺, pH 2.3)下7种分析物在6.5 min内实现基线分离。考察了样品中添加的磷酸浓度和乙腈浓度、水柱长度、电动进样时间与电压对场强放大富集效率及重现性的影响。最佳的富集条件为: 水柱注入3.45 kPa(0.5 psi)×6 s,样品中添加40%(v/v)乙腈和0.6×10~3mol/L磷酸,进样电压与进样时间为10 kV×10 s。线性范围为3～1000 μg/L(R2＞0.996),检出限为0.26～2.75 μg/L,将已有方法的检测灵敏度提高了1～3个数量级。在2种市售黑色染发剂中均检测到间氨基苯酚,含量分别为7.32 mg/g和1.34 mg/g。平均加标回收率为74%～108%。该方法灵敏度高、快速、重现性好、成本低,可供多种样品基质中痕量苯胺类污染物及其他阳离子物质的测定借鉴使用。     

应用移动反应界面富集技术进行毛细管电泳尿液指纹分析

快速灵敏的尿液指纹图谱分析对于临床诊断中发现新的生物标记至关重要。该文建立了一种简便、快速、灵敏的移动反应界面(MRB)介导的富集技术进行毛细管电泳尿液指纹图谱分析。MRB由25 mmol/L甘氨酸（Gly）-HCl（pH 2.5）作为样品缓冲液和50 mmol/L Gly-NaOH（pH 12.3）作为电泳缓冲液形成。与常规的毛细管区带电泳只能观察到尿液中不到10个峰相比,采用MRB可以观察到超过80个峰并将检测灵敏度提高了至少十几倍,显示该方法对于代谢组学分析具有重要的意义。     

Field-amplified on-line sample stacking for determination of carnosine-related peptides by capillary electrophoresis

An on-line sample stacking method, namely field-amplified sample injection, has been developed for the separation and determination of carnosine, anserine, and homocarnosine by capillary electrophoresis. Using electrokinetic injection, about 130- to 160-fold improvement of sensitivity was achieved without loss of separation efficiency when compared to conventional sample injection. For conventional injection, the samples were dissolved in running buffer and then hydrodynamically injected for 10 s (3.45 kPa). Various parameters affecting separation and sample stacking were optimized. Under optimum conditions, linear responses were obtained over two orders of magnitude and the detection limits (defined as S/N = 3) of carnosine, anserine, and homocarnosine were 1.5 x 10(-8) to 1.6 x 10(-8) mol/L.     

Determination of pesticides in wine using micellar electrokinetic chromatography with UV detection and sample stacking

In this work, the analysis of a group of four fungicides (pyrimethanil, nuarimol, procymidone and cyprodinil) and one insecticide (pirimicarb) by micellar electrokinetic chromatography (MEKC) with UV detection using the on-line preconcentration strategy called reversed electrode polarity stacking mode (REPSM) is proposed. After optimisation, an adequate separation electrolyte for the separation and stacking of these pesticides was obtained which consisted of 100 mM borate, 60 mM sodium dodecyl sulphate (SDS), at pH 9.0 and 2% 2-propanol. The use of this running buffer together with the REPSM preconcentration method provided limits of detection (LODs) between 38.3 and 241 microg/L. In order to apply the developed methodology for the analysis of these pesticides in wine samples, several off-line preconcentration strategies (mainly, solid-phase extraction, SPE, and solid-phase microextraction, SPME) were tested. Although the use of a SPE procedure, optimized in this work for water samples, using Oasis HLB cartridges, provided mean recovery values between 79 and 100% for spiked water samples, it could not be applied to the extraction of these pesticides from wine samples due to high interference from the sample matrix. However, the use of a SPME procedure using polydimethylsiloxane/divynilbenzene (PDMS/DVB) fibers allowed the selective extraction of four of the five pesticides which could be perfectly determined. The final combination of the off-line SPME and on-line REPSM preconcentration strategies allowed obtaining LODs between 17.6 and 32.3 microg/L.     

Separation and online preconcentration by multistep stacking with large-volume injection of anabolic steroids by capillary electrokinetic chromatography using charged cyclodextrins and UV-absorption detection

The separation of three common anabolic steroids (methyltestosterone, methandrostenolone and testosterone) was performed for the first time by capillary EKC. Different charged CD derivatives and bile salts were tested as dispersed phases in order to achieve the separation. A mixture of 10 mmol/L succinylated-beta-CD with 1 mmol/L beta-CD in a 50 mmol/L borate buffer (pH 9) enabled the separation of the three anabolic steroids in less than 9 min. Concentration LODs, obtained for these compounds with low absorption of UV light, were approximately 5 x 10(-5) mol/L. The use of online reverse migrating sample stacking with large-volume injection (the effective length of the capillary) enabled to improve the detection sensitivity. Sensitivity enhancement factors (SEFs) ranging from 95 (for testosterone) to 149 (for methyltestosterone) were achieved by single stacking preconcentration. Then, the possibilities of multistep stacking to improve the sensitivity for these analytes were investigated. SEFs obtained by double stacking preconcentration ranged from 138 to 185, enabling concentration LODs of 2.79 x 10(-7) mol/L (for methyltestosterone), 3.47 x 10(-7) mol/L (for testosterone) and 3.56 x 10(-7) mol/L (for methandrostenolone). Although online triple stacking preconcentration was achieved, its repeatability was very poor and SEFs for the studied analytes were not calculated.     

微乳液毛细管电动色谱-场放大富集法灵敏分析尿液中的9种麻醉剂类药物

建立了一种微乳液毛细管电动色谱(MEEKC)-场放大富集(FASI)分析尿液中多种麻醉剂(吗啡、可待因、纳洛酮、海洛因、蒂巴因、可卡因、哌替啶、芬太尼、美沙酮)的方法。考察了微乳液组成、分离电压等因素的影响,得到的最佳微乳液组成(质量分数)为0.6%十二烷基硫酸钠、1.2%正丁醇、0.6%乙酸乙酯和97.6% 10 mmol/L硼砂缓冲液(pH 9.5);分离电压为25 kV。在上述微乳体系中,9种化合物在15 min内得到了基线分离。采用场放大在线富集技术提高了分析灵敏度,检出限(S/N=3)低至0.3 μg/L。模拟尿样样品中9种麻醉剂的加标回收率介于79.4%～119.9%之间,日内相对标准偏差小于5.5%。将该方法应用于美沙酮大鼠体外代谢样品的测定,结果令人满意。