Ultra high performance supercritical fluid chromatography coupled with tandem mass spectrometry for screening of doping agents. I: Investigation of mobile phase and MS conditions

The conditions for the analysis of selected doping substances by UHPSFC–MS/MS were optimized to ensure suitable peak shapes and maximized MS responses. A representative mixture of 31 acidic and basic doping agents was analyzed, in both ESI+ and ESI− modes. The best compromise for all compounds in terms of MS sensitivity and chromatographic performance was obtained when adding 2% water and 10 mM ammonium formate in the CO₂/MeOH mobile phase. Beside mobile phase, the nature of the make-up solvent added for interfacing UHPSFC with MS was also evaluated. Ethanol was found to be the best candidate as it was able to compensate for the negative effect of 2% water addition in ESI− mode and provided a suitable MS response for all doping agents.     

手性流动相添加法拆分酮康唑外消旋体

采用C18反相色谱柱,利用在流动相中加入手性选择剂的方法实现酮康唑对映体的拆分。研究了手性选择剂的种类及浓度、流动相pH值、甲醇比例和柱温等因素对酮康唑手性分离的影响,结果表明磺丁基-β-环糊精可以使酮康唑对映体完全分离,最后选择的流动相组成为甲醇-0.02 mol/L磷酸二氢钠(体积比为60∶40,含0.02%三乙胺和1.0 mmol/L磺丁基-β-环糊精,用稀磷酸调节pH值到3.00)。酮康唑对映体在6 min内得到基线分离,分离度为2.05。方法简便,分离效果好,对酮康唑对映体的拆分具有应用价值。     

Determination of three estrogens and bisphenol A by functional ionic liquid dispersive liquid‐phase microextraction coupled with ultra‐high performance liquid chromatography and ultraviolet detection

A hydroxyl‐functionalized ionic liquid, 1‐hydroxyethyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide, was employed in an improved dispersive liquid‐phase microextraction method coupled with ultra high performance liquid chromatography for the enrichment and determination of three estrogens and bisphenol A in environmental water samples. The introduced hydroxyl group acted as the H‐bond acceptor that dispersed the ionic liquid effectively in the aqueous phase without dispersive solvent or external force. Fourier transform infrared spectroscopy indicated that the hydroxyl group of the cation of the ionic liquid enhanced the combination of extractant and analytes through the formation of hydrogen bonds. The improvement of the extraction efficiency compared with that with the use of alkyl ionic liquid was proved by a comparison study. The main parameters including volume of extractant, temperature, pH, and extraction time were investigated. The calibration curves were linear in the range of 5.0–1000 μg/L for estrone, estradiol, and bisphenol A, and 10.0–1000 μg/L for estriol. The detection limits were in the range of 1.7–3.4 μg/L. The extraction efficiency was evaluated by enrichment factor that were between 85 and 129. The proposed method was proved to be simple, low cost, and environmentally friendly for the determination of the four endocrine disruptors in environmental water samples.     

高效液相色谱手性流动相法拆分酮基布洛芬对映体

以Lichrospher C18为分析柱, 将β-环糊精、2,6-二甲基-β-环糊精、2,3,6-三甲基-β-环糊精分别作为手性流动相添加剂, 系统地研究了R,S-酮基布络芬对映体在HPLC系统中的拆分. 建立了以2,3,6-三甲基-β-环糊精为手性流动相添加剂分离R,S-酮基布络芬对映体方法.     

尿素醇解法制氨基甲酸甲酯体系的反相高效液相色谱分析

采用反相高效液相色谱法,在两根串联的C18柱上以甲醇-水为流动相,在8min内将尿素和氨基甲酸甲酯进行分离,在215nm波长下检测。在甲醇溶液中的质量浓度0~16%和0~50%范围内其峰面积和质量浓度呈良好的线性关系,线性回归方程分别为AUrea=148565x-39384,R2=0.9995;AMC=69055x-90493,R2=0.9985。     

高效液相色谱法分析硫双灭多威

研究了用高效液相色谱分析杀虫剂硫双灭多威的方法。在反相ＯＤＳ柱上,用甲醇－水作流动相,紫外检测器检测,以邻苯二甲酸二甲酯作内标定量。方法快速、准确,重现性好,线性范围宽,变异系数为０．１８％,回收率为９９．８９％,色谱分析周期仅为８ｍｉｎ。     

高效液相色谱手性固定相法拆分阿折地平对映体

建立了阿折地平对映体的高效液相色谱拆分方法。采用Chiralpak AD-H (250 mm×4.6 mm, 5.0 μm, Daicel公司)手性色谱柱在正相条件下直接拆分阿折地平对映体,考察了固定相种类、流动相组成及柱温等对阿折地平对映体分离的影响。确定了最佳的拆分条件: 流动相为正己烷-异丙醇(90:10, v/v),流速为0.8 mL/min,检测波长为254 nm;柱温为20 ℃;在此条件下阿折地平对映体的分离度为3.3。该法简单快速,重现性好。     

Emulsification liquid phase microextraction followed by on-line phase separation coupled to high performance liquid chromatography

An emulsification liquid phase microextraction followed by on-line phase separation coupled to high performance liquid chromatography (HPLC) is introduced based on a novel idea for the separation of dispersed organic phase from aqueous phase. In this method, the dispersed organic extraction phase was filtered using an in-line filter and it was separated from the water sample. The new approach is simple and, in addition to improving some limitations of the conventional emulsification liquid phase microextraction, eliminates the need for centrifugation in the phase separation step.     

以离子液体作流动相添加剂的高效液相色谱法测定复方苦参注射液中4种生物碱

将离子液体1-丁基-3-甲基咪唑四氟硼酸盐(［BMIM］BF4)作为流动相添加剂建立了同时测定复方苦参注射液中4种主要生物碱的HPLC分析方法。以Agilent TC-C18柱(250 mm×4.6 mm, 5 μm)为分离柱,甲醇-0.1%磷酸水溶液(含2.2×10-4mol/L ［BMIM］BF4)(5:95, v/v)为流动相,流速1.0 mL/min,柱温30 ℃,进样量20 μL,在205 nm下检测。结果表明,苦参碱、槐定碱、氧化槐果碱以及氧化苦参碱的质量浓度分别在25.8～155.0 mg/L, 40.0～240.0 mg/L, 21.7～130.0 mg/L和37.5～225.0 mg/L范围内线性关系良好,相关系数均大于0.9990,平均回收率(n=9)在96.2%和98.9%之间。离子液体的加入能明显改善C18柱分离生物碱的色谱峰形并提高分离度。本法简便、快速、重复性好,可用于复方苦参注射液中生物碱的分离与测定。     

用快速分离柱高效液相色谱法测定烟草中的几种酚

研究了用快速分离柱高效液相色谱法测定烟草样品中的苯酚、苯二酚和甲基苯酚. 烟草样品中的酚经水蒸汽蒸馏分离后用Waters Sep-Pak-C18固相萃取小柱富集, 以ZORBAX Stable Bound (4.6 mm i.d.×20 mm, 1.8 μm) 快速分离柱为固定相, 0.05 mol/L KH2PO4缓冲溶液-甲醇梯度为流动相, 几种主要酚在2.0 min 内可达到基线分离;该方法的相对标准偏差为2.1%～3.6%, 标准加入的回收率为88%～97%, 已用于几种烟草样品测定.     

固相萃取-高效液相色谱法同时测定食品中4种合成色素

以可代替使用的水溶性合成色素-亮黑BN、固绿FCF、酸性红、酸性黄36为研究对象,建立了高效液相色谱同时测定食品中4种合成色素的方法。样品通过WAX固相萃取柱富集净化,10%氨化甲醇洗脱,采用C18色谱柱分离,以甲醇和10 mmol/L乙酸铵水溶液作为流动相梯度洗脱,外标法定量。通过固相萃取柱净化后,杂质对待测物的干扰明显降低,优化色谱条件下,4种色素在0.10~10.0 mg/L质量浓度范围内,线性良好,相关系数(r)≥0.9995。方法回收率为92.6%~101.8%,相对标准偏差(RSD)≤5.4%,方法检出限为0.01~0.04 mg/kg。该方法灵敏度高,准确可靠,适合食品中亮黑BN、固绿FCF、酸性红、酸性黄36的同时测定。     

反相高效液相色谱法快速测定大麦籽粒中13种酚酸类化合物

建立了快速测定大麦籽粒中13种酚酸类化合物(没食子酸、原儿茶酸、绿原酸、对羟基苯甲酸、咖啡酸、香草酸、丁香酸、间羟基苯甲酸、对香豆酸、阿魏酸、藜芦酸、邻香豆酸和水杨酸)的反相高效液相色谱方法.采用SUPELCOAscentis(@) C18色谱柱(150 mm×4.6 mm,5μm)分离,流动相为甲醇-0.1％甲酸水溶...     

直链淀粉手性固定相高效液相色谱法拆分比索洛尔对映体

采用直链淀粉手性固定相高效液相色谱法在正相条件下直接拆分了比索洛尔对映异构体。分别以异丙醇、乙醇为有机改性剂,考察了流动相的组成与配比、流速及柱温等因素对比索洛尔对映体分离的影响。确定了比索洛尔对映体的最佳拆分条件:流动相正己烷-乙醇-二乙胺(体积比为88∶12∶0.1),流速0.6 mL/min,检测波长270 nm,柱温20 ℃。该方法可快捷、简便地拆分比索洛尔对映体。     

除草剂双苯唑快的反相高效液相色谱法分析

采用反相高效液相色谱法分析除草剂——双苯唑快,色谱柱为Ｓｅｌｅｃｔｏｓｉｌ５Ｃ１８不锈钢柱,检测波长为２５４ｎｍ,用Ｖ（甲醇）Ｖ（水）＝６０４０（ｐＨ３）为流动相。方法的变异系数为０．４１％,平均回收率为９９．３４％,线性相关系数为０．９９９９。方法快速、准确。     

Convenient estimation of the mobile phase volume for water-rich eluents in reversed-phase liquid chromatography

Summary Oxalodihydroxamic acid is proposed as a UV-detectable substitute for D₂O for the convenient estimation of the mobile phase volume (V_m) of water-rich hydro-organic eluents in reversed-phase liquid chromatography. The retention volume of oxalodihydroxamic acid deviates less than 6% from that of D₂O in 0 to 50% methanol-and acetonitrile-water eluents on C₁, C₈, and C₁₈ reversed-phase supports; it is independent of the amount injected from 10ng to 20μg when monitored at 254nm, although the sensitivity is about four-fold greater at 219 nm. The pH should be maintained between about 2 and 4. The deviation from the D₂O retention volume on supports of typical porosity is attributed, at least in part, to a size-exclusion effect. Simple hydroxamic acids can be used as a homologous series for the estimation of V_m over most of the methanol- and acetonitrile-water concentration ranges by the linearization of retentions of homologous series method. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

中空纤维三相液相微萃取-高效液相色谱法测定环境水样中7种苯氧羧酸类除草剂

建立了利用中空纤维三相液相微萃取-高效液相色谱联用技术(HF-LPME-HPLC)同时测定环境水中痕量麦草畏(dicamba)、氟草烟(fluroxypyr)、4-氯苯氧乙酸(4-CPA)、2甲4氯(MCPA)、2,4-滴(2,4-D)、2,4-滴苯氧丁酸(2,4-DB)和2甲4氯苯氧丁酸(MCPB)等7种苯氧羧酸类除草剂的分析方法。考察了萃取剂﹑接受相和给出相pH值、萃取时间﹑搅拌速度和盐效应等对检测的影响,通过正交试验优化萃取条件,得到的最佳萃取条件为正辛醇作萃取剂,给出相pH为3,接受相pH为12,萃取30 min,搅拌速度400 r/min。结果表明7种除草剂在较宽的线性范围内线性良好,相关系数为0.9953～0.9988,检出限(信噪比为3)为0.2～1.0 μg/L,富集倍数为76.7～121,加标回收率为68%～104%,相对标准偏差为3.2%～8.1%。该法灵敏度高、操作简单、检测快速、有机溶剂消耗少,为环境水样中痕量苯氧羧酸类除草剂残留的分析提供了有益的参考。     

固相萃取-高效液相色谱法同时测定牛奶中22种磺胺类兽药残留

建立了一种基于固相萃取技术同时测定牛奶中22种磺胺类兽药残留的高效液相色谱分析方法.样品经乙腈-甲酸混合溶液提取,乙腈饱和的正己烷除酯后,HLB固相萃取柱净化,以甲醇-2 mmol/L乙酸铵(含0.2％乙酸)为流动相进行梯度洗脱,XBridge C18色谱柱进行分离,采用光电二极管阵列检测器检测,外标法定量.磺胺类化合...     

高效液相色谱法手性分离联萘二酚苯甲酸酯对映体

采用Chirex(S)-LEU(S)-NEA、ChiralcelOD-H和ChiralpakAD-H手性色谱柱直接拆分了2′-羟基-1,1′-联萘-2-苯甲酸酯(HBNB)、1,1′-联萘-2,2′-二苯甲酸酯(BNDB)和2′-甲氧基-1,1′-联萘-2-苯甲酸酯(MBNB)对映体。分别考察了流动相组成、柱温和化合物结构对手性分离的影响。结果表明:3对联萘二酚苯甲酸酯对映体在ChiralpakAD-H柱上的拆分效果最好。当采用正己烷/异丙醇(40/60,v/v)为流动相时,HBNB、BNDB和MBNB对映体的分离因子(α)和分离度(Rs)分别为1.76、1.74、1.40和6.47、7.81、4.75。对比联萘二酚(BN)的分离,从联萘分子中2-位取代基、对映体出峰顺序和热力学参数等方面探讨了相关手性分离机理。     

Methylammonium formate as a mobile phase modifier for totally aqueous reversed-phase liquid chromatography

Although alkylammonium ionic liquids (ILs) such as ethylammonium nitrate and ethylammonium formate have been used as mobile phase "solvents" for liquid chromatography (LC), we have shown that the IL methylammonium formate (MAF), in part because of its lower viscosity as compared to other ILs, can be an effective replacement for methanol (MeOH) in reversed-phase LC. Plots of log retention factor versus the fraction of MeOH and MAF in the mobile phase indicate quite comparable solvent strength slope values of 2.50 and 2.05, respectively. Using a polar endcapped C18 column, furazolidone and nitrofurantoin using 20% MAF-80% water could be separated in 22 min but no baseline separation is possible using MeOH as the modifier, even down to 10%. Suppression of silanol peak broadening effects by MAF is important, permitting a baseline separation of pyridoxine, thiamine, and nicotinamide using 5% MAF-95% water at 0.7 mL/min. Using 5% MeOH-95% water, severe peak broadening for thiamine is evident. The compatibility of MAF as a mobile phase modifer at the 5% level for LC with mass spectrometry detection of water-soluble vitamins is also shown.     

一种新型核壳型色谱固定相在高效液相色谱中的评价及应用

采用扫描电镜、透射电镜和氮气吸附法对制备的新型核壳型色谱固定相进行了表征,结果表明该固定相单分散性好、表面放射状孔道壳层结构均一、孔径分布窄。对该核壳材料的表面进行C18键合修饰,考察其基本色谱性能,色谱柱的理论塔板数超过150000块/m,色谱峰峰形对称,甲苯与乙苯的保留因子之比为1.45,亚甲基选择性优异。将该核壳材料应用于汽车尾气中醛酮类化合物的检测,在优化的色谱条件下,2,4-二硝基苯肼（DNPH）衍生的醛酮类化合物在15 min内获得了较好的分离效果。该核壳型C18色谱固定相具有分离速度快、选择性好、柱效高等特点,适于复杂样品的高效、快速分离分析。