Rapid and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations by ion pair chromatography coupled with direct conductivity detection
Rapid and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations by ion pair chromatography coupled with direct conductivity detection
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DOI：
10.1016/j.cclet.2016.05.034
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发表时间：
2017
影响因子：
9.1
通讯作者：
Xin-xin Zhang;Yong-qiang Liu;Hong Yu;Renqing Zhang
中科院分区：
文献类型：
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作者：
Xin-xin Zhang;Yong-qiang Liu;Hong Yu;Renqing Zhang
建立了一种在硅胶整体柱上快速同时测定哌啶鎓和吡咯烷鎓离子液体阳离子的离子对色谱-直接电导检测法。考察了移动的相、柱温和流速对阳离子保留的影响。讨论了保留规则。庚磺酸钠作为离子对试剂比戊磺酸钠更适合于哌啶鎓和吡咯烷鎓阳离子的分离和测定。离子对试剂浓度的增加导致阳离子保留时间的增加。随着乙腈含量和移动的流量的增加，阳离子的保留时间变短。哌啶鎓和吡咯烷鎓阳离子的保留是一个放热过程，并且阳离子的保留符合碳数规则。色谱分析采用Chromolith Speed ROD RP-18 e色谱柱，以0.5 mmol/L庚烷磺酸钠-5%乙腈为移动的相，流速为3.0 mL/min，柱温为30 °C。N-甲基-N-乙基哌啶鎓、N-甲基-N-丙基哌啶鎓、N-甲基-N-丁基哌啶鎓和N-甲基-N-乙基吡咯烷鎓、N-甲基-N-丙基吡咯烷鎓、N-甲基-N-丁基吡咯烷鎓阳离子在10 min内分离。检出限（S/N = 3）在0.19 ~ 3.08mg/L之间。峰面积的相对标准偏差（n= 5）小于1.2%。该方法已用于离子液体样品中哌啶鎓和吡咯烷鎓阳离子的测定。离子液体阳离子的加标回收率在96%和111%之间。该方法准确、可靠、快速，具有较好的实用性。
A method of ion-pair chromatography with direct conductivity detection was developed on a silica-based monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations. The effects of the mobile phase, column temperature and flow rate on the retention of the cations were investigated. The retention rules were discussed. As an ion-pair reagent, sodium heptanesulfonate is more suitable than sodium pentanesulfonate for the separation and determination of piperidinium and pyrrolidinium cations. The increase of ion-pair reagent concentration led to the increased retention time of the cations. When acetonitrile content and mobile phase flow were increased, the retention time of the cations became shorter. The retention of piperidinium and pyrrolidinium cations is an exothermic process, and the retention of the cations conforms to the carbon number rule. The chromatographic analysis was performed using the Chromolith Speed ROD RP-18e column, 0.5 mmol/L sodium heptanesulfonate-5% acetonitrile as the mobile phase at a flow rate of 3.0 mL/min and column temperature of 30 °C. Separation ofN-methyl-N-ethyl piperidinium,N-methyl-N-propyl piperidinium,N-methyl-N-butyl piperidinium andN-methyl-N-ethyl pyrrolidinium,N-methyl-N-propyl pyrrolidinium,N-methyl-N-butyl pyrrolidinium cations were achieved within 10 min. The detection limits (S/N = 3) were between 0.19 and 3.08 mg/L. Relative standard deviations (n= 5) for peak areas were less than 1.2%. The method has been applied to the determination of piperidinium and pyrrolidinium cations in ionic liquid samples. The spiked recoveries of ionic liquid cations were between 96% and 111%. The method is accurate, reliable, rapid, and has a better practicability.