离子交换色谱分离-紫外检测法测定吡啶离子液体阳离子

建立了用离子交换色谱分离-紫外检测法测定N-乙基吡啶、N-丁基吡啶和N-丁基四甲基吡啶3种吡啶离子液体阳离子的方法。采用磺酸型阳离子交换柱,以乙二胺-柠檬酸-乙腈为流动相,研究了流动相和色谱柱温度对离子保留行为的影响和规律。实验发现,吡啶阳离子的保留过程是放热过程。优化后的色谱条件:流动相为乙二胺(0.2 mmol//L)-柠檬酸(0.3 mmol//L)-乙腈(0.5%,v/v,pH=4.2),流动相流速为1.0mL/min,色谱柱为Shim-pack IC-C1阳离子交换柱,色谱柱温度为30℃。在此条件下3种吡啶阳离子可以达到基线分离。所测阳离子的检出限(S/N=3)分别为0.01、0.01、0.02mg/L,峰面积的相对标准偏差(n=5)小于0.8%。紫外检测法测定化学实验室合成的吡啶离子液体样品,样品加标后测得的加标回收率在96.3%~104%。方法准确、可靠、快速,具有较好的实用价值。     

离子色谱-紫外检测法分离测定吡啶离子液体阳离子

建立了用离子色谱-紫外检测法分离测定3种吡啶离子液体阳离子(N-乙基吡啶、N-丁基吡啶和N-丁基四甲基吡啶)的方法。采用磺酸型阳离子交换柱,以乙二胺-柠檬酸-乙腈为流动相,考察了流动相和色谱柱温度对离子保留的影响,探讨了保留规律。实验发现,吡啶阳离子的保留过程是放热过程。优化的色谱条件为：流动相是0.2 mmol//L乙二胺-0.3 mmol//L柠檬酸-0.5%(v/v)乙腈(pH 4.2),流速1.0 mL/min,柱温30℃。在此条件下可以基线分离3种吡啶阳离子。所测阳离子的检出限(S/N=3)分别为0.01、0.01、0.02 mg/L,峰面积的相对标准偏差(n=5)小于0.8%。将此方法应用于分析实验室合成的吡啶离子液体样品,加标回收率在96.3%～103.7%之间。本方法准确、可靠、快速,具有较好的实用性。     

整体柱离子对色谱-紫外检测法快速测定对甲苯磺酸根

研究了整体柱离子对色谱结合紫外检测的方法分析对甲苯磺酸根(C7H7SO3-)。采用反相硅胶整体柱,以氢氧化四丁基铵-柠檬酸-乙腈为流动相,考察了紫外检测波长、流动相组成、色谱柱温度和流速对离子保留的影响。色谱条件经过优化,在紫外检测波长230 nm,流动相为0.4 mmol·L-1氢氧化四丁基胺(TBA)-0.13mmol·L-1柠檬酸-15%(v/v)乙腈(pH 5.5),流速3.0 mL·min-1,柱温40℃的条件下,C7H7SO3-的保留时间为1.25 min内。常见无机阴离子(Cl-,NO3-)不干扰测定。在0.7~100 mg·L-1范围内,线性回归方程的相关系数为0.9997,峰面积的相对标准偏差(RSD,n=5)为1.0%,检出限(S/N=3)为0.2 mg·L-1。该方法应用于检测实验室合成离子液体中的C7H7SO3-,加标回收率为101%。方法简单、快速。     

离子色谱-直接电导检测法测定离子液体的阴离子p-甲苯磺酸根

建立了离子液体阴离子p-甲苯磺酸根的离子色谱-直接电导检测分析方法。采用Shim-pack IC-A3季铵型阴离子交换色谱柱,考察了流动相种类和色谱柱温度对分离测定p-甲苯磺酸根的影响。确定最佳色谱条件为:以1.2 mmol/L柠檬酸-15%乙腈混合水溶液(pH 5.0)为流动相,流速1.0 mL/min,柱温45℃。在此条件下,p-甲苯磺酸根与常见无机阴离子(氟离子、氯离子、溴离子和硝酸根)可以获得很好的分离。该方法测定p-甲苯磺酸根的线性范围为4～100 mg/L,检出限(S/N=3)为1.22 mg/L,保留时间和峰面积的相对标准偏差(n=5)分别为0.42%和1.8%。将方法用于离子液体中p-甲苯磺酸根的测定,加标回收率为99.6%。     

离子液体的阴离子三氟乙酸根、硫氰酸根、四氟硼酸根和三氟甲磺酸根的离子对色谱-直接电导检测法分析

建立了同时测定离子液体的阴离子三氟乙酸根、硫氰酸根、四氟硼酸根和三氟甲磺酸根的反相离子对色谱-直接电导检测方法。采用Diamonsil C18分离柱,以离子对试剂-苹果酸-乙腈水溶液为流动相,从流动相组成和色谱柱温度两方面讨论并确定了优化的色谱条件,即以0.15 mmol/L氢氧化四丁铵-0.099 mmol/L苹果酸-20%(v/v)乙腈混合水溶液(pH 6.5)为流动相,柱温25 ℃。在此条件下,三氟乙酸根、硫氰酸根、四氟硼酸根和三氟甲磺酸根离子均达到基线分离,且不受其他常见阴离子氟离子、氯离子、溴离子、硝酸根、硫酸根的干扰。三氟乙酸根、硫氰酸根、四氟硼酸根和三氟甲磺酸根离子的检出限(信噪比为3)分别为0.21、0.07、0.36、0.12 mg/L。将方法应用于测定离子液体中三氟乙酸根、硫氰酸根、四氟硼酸根和三氟甲磺酸根离子,加标回收率为95.0%～104.6%。该法简便、快速、灵敏度较高,可满足离子液体样品的检测要求。     

离子对色谱法同时分离测定吡啶及咪唑离子液体阳离子

建立了用紫外检测的反相离子对色谱梯度淋洗同时分离测定4种吡啶离子液体阳离子和5种咪唑离子液体阳离子的方法。实验采用ZORBAX Eclipse XDB-C18反相色谱柱,以离子对试剂水溶液(用柠檬酸调节pH值)+乙腈为流动相,考察了离子对试剂种类和浓度、乙腈浓度和色谱柱温度对保留的影响,探讨了相关保留规律,确定最佳色谱条件为:流速1.0 mL/min、柱温30℃,以1.0 mmol/L庚烷磺酸钠水溶液(pH 4.0)-乙腈为淋洗液进行梯度洗脱。在此条件下,4种吡啶阳离子和5种咪唑阳离子在15 min内达到基线分离。检出限(S/N=3)为0.31～0.54 mg/L,峰面积的相对标准偏差为0.10%～0.75%。将该方法用于实验室合成的离子液体样品分析,加标回收率为94%～98%。该方法准确、可靠,具有较好的实用性。     

离子色谱-直接电导检测法分析哌啶离子液体阳离子

建立了离子色谱-直接电导检测法分析N-甲基,乙基哌啶(［MEPi］+)、N-甲基,丙基哌啶(［MPPi］+)和N-甲基,丁基哌啶(［MBPi］+) 3种哌啶离子液体阳离子的方法。采用磺酸型阳离子交换色谱柱,以乙二胺-柠檬酸-乙腈为流动相。考察了流动相组成及色谱柱温度对哌啶阳离子保留的影响,并讨论了保留规律。结果表明,哌啶阳离子的保留是一个放热过程,即哌啶阳离子的保留时间随着色谱柱温度的升高而缩短,且哌啶阳离子同系物的保留符合碳数规律。在以0.2 mmol/L乙二胺-0.3 mmol/L柠檬酸-3%(v/v)乙腈(pH 4.4)为流动相、流速1.0 mL/min、柱温30 ℃条件下,［MEPi］+、［MPPi］+和［MBPi］+3种哌啶阳离子可以在7 min内分离,检出限(信噪比为3)分别为0.14、0.20和0.56 mg/L,峰面积的相对标准偏差(n=5)在1.2%以下。将此方法应用于分析实验室合成的哌啶离子液体样品,加标回收率在97.6%与105.1%之间。本方法准确、可靠、快速,具有较好的实用性。     

反相离子对色谱-直接电导检测法分析六氟磷酸根离子液体阴离子

建立了反相离子对色谱-直接电导检测六氟磷酸根(PF6-)离子液体阴离子的分析方法。用DiamonsilC18反相色谱柱为分离柱,以离子对试剂-柠檬酸-乙腈混合水溶液为流动相,考察了离子对试剂、乙腈含量、pH值及色谱柱温度对六氟磷酸根保留的影响,并讨论了相关保留机理。在优化的色谱条件下,即流动相为0.05 mmol/L氢氧化四丁铵-0.038 mmol/L柠檬酸-35%乙腈(pH 5.5),流速1.0 mL/min,色谱柱温度40℃时,PF6-与其它常见阴离子(F-、Cl-、Br-、NO3-、SO24-、BF4-)达到基线分离且保留时间在15 min内。方法检出限(S/N=3)为0.25 mg/L,标准曲线的线性范围为0.5～100.0 mg/L,峰面积和保留时间的相对标准偏差(n=5)分别为0.17%和0.15%。该法用于1-丁基-3-甲基咪唑六氟磷酸盐和1-丙基-2,3-二甲基咪唑六氟磷酸盐两种离子液体中PF6-的测定,加标回收率分别为99%和104%。该方法简单、准确、可靠,实用性好。     

离子色谱-直接电导检测法分离测定吗啉离子液体阳离子

建立了离子色谱-直接电导检测法分析N-甲基乙基吗啉([MEMo]+)、N-甲基丙基吗啉([MPMo]+)2种吗啉离子液体阳离子的方法。采用磺酸型阳离子交换色谱柱,以乙二胺-乙腈为流动相,研究了色谱柱、流动相、色谱柱温度对吗啉阳离子保留的影响,并讨论了保留规律。结果表明,吗啉阳离子的保留基本属于离子交换模式,是一个放热过程。在柱温30℃,流速1.0 mL/min,以0.1 mmol/L乙二胺-0.5%乙腈(用盐酸调节至pH 5.0)为流动相条件下,[MEMo]+和[MPMo]+阳离子可在4 min内得到基线分离,检出限(S/N=3)分别为0.08、0.13 mg/L,峰面积的相对标准偏差(RSD,n=5)不大于1.5%。将此方法用于测定实验室合成的吗啉离子液体样品,加标回收率为94.0%～106.0%。方法准确、可靠、快速,具有较好的实用性,可满足离子液体样品的检测要求。     

离子对色谱-间接紫外检测法分析哌啶离子液体阳离子

建立了快速分析无紫外光吸收的哌啶离子液体阳离子的离子对色谱-间接紫外检测法。采用反相C18色谱柱,以背景紫外吸收试剂-离子对试剂水溶液/有机溶剂为流动相分离哌啶离子液体阳离子。研究了背景紫外吸收试剂、检测波长、离子对试剂、有机溶剂、柱温、流速对分离测定哌啶阳离子的影响。最佳色谱条件为：以0.5 mmol/L对氨基苯酚盐酸盐-0.1 mmol/L庚烷磺酸钠水溶液/甲醇（80：20,v/v）为流动相,检测波长210 nm,柱温30 ℃,流速1.0 mL/min。在此条件下,3种哌啶阳离子可在4 min之内基线分离。所测阳离子的检出限（S/N=3）为0.137~0.545 mg/L,峰面积和保留时间的相对标准偏差（n=5）分别不高于0.72%和0.37%。将此方法用于分析实验室合成的哌啶类离子液体,加标回收率为97.0%~98.4%。本方法简便、快速,重现性、线性关系等均能满足哌啶类离子液体阳离子的定量分析要求。     

Ionic liquids as mobile phase additives for determination of thiocyanate and iodide by liquid chromatography

An analytical method was developed for the simultaneous determination of thiocyanate and iodide by reversed‐phase liquid chromatography with UV detection using imidazolium ionic liquids as mobile phase additives. The chromatographic behaviors of the two anions on a C₁₈ column were studied and compared with four types of reagents including imidazolium ionic liquids, pyridinium ionic liquids, 4‐aminophenol hydrochloride and tetrabutylammonium as mobile phase additives. The effects of the concentrations of imidazolium ionic liquids, organic solvents and detection wavelength on separation and detection of the anions were investigated. The role of ionic liquids, retention rules and mechanisms were discussed. The separation of the anions was performed on the C₁₈ reserved‐phase column using acetonitrile‐0.3 mmol/L 1‐amyl‐3‐methylimidazolium tetrafluoroborate (10:90, v/v) as mobile phase, with column temperature of 35°C, flow rate of 1 mL/min and detection wavelength of 210 nm. Under these conditions, the two anions can be completely separated within 6 min. The limits of detection were 0.05 mg/L. The method was applied for the determination of thiocyanate and iodide in ionic liquid samples and iodide drugs, and the spiked recoveries ranged from 97 to 101%. The method is simple, accurate and meets the requirements of quantitative analysis for thiocyanate and iodide.     

整体柱离子对色谱-间接紫外检测法快速测定N-甲基,丙基吗啉阳离子

建立了快速分析无紫外吸收的N-甲基,丙基吗啉阳离子的离子对色谱-间接紫外检测法。采用反相C18硅胶整体柱,以背景紫外吸收试剂-离子对试剂-有机溶剂为流动相。研究了背景紫外吸收试剂、检测波长、离子对试剂、有机溶剂、柱温、流速对吗啉阳离子测定的影响。最佳色谱条件为:(0.5 mmol/L对氨基苯酚盐酸盐-0.1 mmol/L庚烷磺酸钠)溶液-甲醇(9:1, v/v)为流动相,检测波长230 nm,柱温30 ℃,流速1.0 mL/min。在此条件下,N-甲基,丙基吗啉阳离子的保留时间为2.966 min,检出限为0.07 mg/L(S/N=3),峰面积的相对标准偏差为2.1%(n=5),保留时间的相对标准偏差为0.02%(n=5)。将此方法用于分析实验室合成的N-甲基,丙基吗啉离子液体,加标回收率为98.8%。结果表明本方法简便、快速。     

反相离子对色谱法测定脱氧精胍菌素药物中的主成分

建立了反相离子对色谱法分离测定脱氧精胍菌素药物中主成分的方法。分别考察了色谱柱类型、离子对试剂种类及浓度、缓冲盐浓度和流动相pH值等参数对实验结果的影响。确定了分离脱氧精胍菌素的最佳条件: C18色谱柱(250 mm×4.6 mm, 5 μm);以5 mmol/L磷酸氢二钾水溶液(含5 mmol/L戊烷磺酸钠,pH 3.6±0.3)-乙腈(90:10, v/v)为流动相,流速为1.0 mL/min;检测波长为210 nm;柱温为30 ℃;进样量为20 μL。该方法实现了对脱氧精胍菌素的良好分离,且线性关系良好,检出限可达0.5 mg/L。     

亲水作用色谱柱与阳离子交换树脂柱结合分离无机离子（英文）

A combination of hydrophilic interaction chromatographic(HILIC) column and a weakly acidic cation-exchange resin(WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography(IC).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC(ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase(ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase(HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC.The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I-> NO-3 > Br-> Cl-> H2PO-4.However,since HILIC-10 could not separate analyte cations,a WCX column(TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions(Na+,NH+4,K+,Mg2+,Ca2+,H2PO-4,Cl-,Br-,NO-3 and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations(RSDs) of analyte ions by the system were in the ranges of 0.02%-0.05% in retention times and 0.18%-5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24-0.30 μmol/L for the cations and 0.31-1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.     

Determination of tetraethyl ammonium by ion-pair chromatography with indirect ultraviolet detection using 4-aminophenol hydrochloride as background ultraviolet absorbing reagent

A method was developed for the determination of tetraethyl ammonium (TEA) by reversed-phase ionpair chromatography with indirect ultraviolet detection. Chromatographic separation was achieved on a reversed-phase C18 column using background ultraviolet absorbing reagent - ion-pair reagent - organic solvent as mobile phase. The effects of the background ultraviolet absorbing reagents, detection wavelength, ion-pair reagents, organic solvents and column temperature on the determination method were investigated and the retention rules discussed. Results found that TEA could be successfully analyzed by using 0.7 μmol/L 4-aminophenol hydrochloride and 0.15 μmol/L 1-heptanesulfonic acid sodium mixed with 20% (v/v) methanol asmobile phase at a UV detection wavelength of 230 nm. Under these conditions, the retention time of tetraethyl ammonium was 2.85 min. The detection limit (S/N = 3) for TEA was 0.06 mg/L. The relative standard deviations (n = 5) for peak area and retention time were 0.35% and 0.02%, respectively. The method has been successfully applied to the determination of synthesized tetraethyl ammonium bromide. Recovery of tetraethyl ammonium after spiking was 99.1%.     

强碱阴离子交换树脂及碱性洗脱剂的离子排阻/阴离子交换色谱法同时测定NH4+ ，NO2-和NO3-（英文）

Ion-exclusion/anion-exchange chromatography(IEC/AEC) on a combination of a strongly basic anion-exchange resin in the OH——form with basic eluent has been developed.The separation mechanism is based on the ion-exclusion/penetration effect for cations and the anion-exchange effect for anions to anion-exchange resin phase.This system is useful for simultaneous separation and determination of ammonium ion(NH+4),nitrite ion(NO-2),and nitrate ion(NO-3) in water samples.The resolution of analyte ions can be manipulated by changing the concentration of base in eluent on a polystyrene-divinylbenzene based strongly basic anion-exchange resin column.In this study,several separation columns,which consisted of different particle sizes,different functional groups and different anion-exchange capacities,were compared.As the results,the separation column with the smaller anion-exchange capacity(TSKgel Super IC-Anion) showed well-resolved separation of cations and anions.In the optimization of the basic eluent,lithium hydroxide(LiOH) was used as the eluent and the optimal concentration was concluded to be 2 mmol/L,considering the resolution of analyte ions and the whole retention times.In the optimal conditions,the relative standard deviations of the peak areas and the retention times of NH+4,NO-2,and NO-3 ranged 1.28%-3.57% and 0.54%-1.55%,respectively.The limits of detection at signal-to-noise of 3 were 4.10 μmol/L for NH+4,1.87 μmol/L for NO-2 and 2.83 μmol/L for NO-3.     

正交设计试验优化高速逆流色谱分离制备玛咖中芥子油苷的条件

基于高速逆流色谱（HSCCC）技术从玛咖中分离制备出两种芥子油苷,苄基芥子油苷（glucotropaeolin, GTL）和甲氧基苄基芥子油苷（glucolimnanthin, GLI）。使用正交设计试验对分离条件进行优化,采用高分辨质谱对制备的组分进行鉴定,采用高效液相色谱法（HPLC）对组分进行定量分析。确定了两个组分GTL与GLI的HSCCC最佳分离条件：溶剂系统为正丁醇-乙腈-200 g/L硫酸铵溶液（1:0.5:2.4, v/v/v）,上相为固定相,下相为流动相,流动相流速2 mL/min,主机转速900 r/min,从玛咖根粗提物中一次性分离得到157.72 mg/kg纯度为97.9%的苄基芥子油苷和31.93 mg/kg的甲氧基苄基芥子油苷,固定相保留率达57.6%。该方法成本低,简便易行,样品损失量小,可大量循环进样制备。