Behavior and use of nonaqueous media without supporting electrolyte in capillary electrophoresis and capillary electrochromatography.
Behavior and use of nonaqueous media without supporting electrolyte in capillary electrophoresis and capillary electrochromatography.
复制标题
DOI：
10.1021/ac9613186
复制
发表时间：
1997-08
影响因子：
7.4
通讯作者：
P. Wright;Andee Lister;J. Dorsey
中科院分区：
文献类型：
--
作者：
P. Wright;Andee Lister;J. Dorsey
研究了五种非水溶剂（乙腈、甲醇、N，N-二甲基甲酰胺、二甲基亚砜、甲酰胺）和去离子水在无电解质添加剂的情况下对电渗流的支持能力。一般而言，发现流量等于或大于典型CE缓冲液系统的流量。通过开管毛细管电泳（CE）测定每种溶剂的介电常数的大小，并与粘度（η）、介电常数（η）和介电常数与粘度的比率（η/η）相关。Zeta电位（zeta）间接从流量数据中推导出来，并制成表格。纯溶剂和传统的CE缓冲液之间的流动行为和zeta进行了比较，并解决了平衡和再现性的问题。在整个组成范围（100%水-100%有机物）内使用含水有机移动的相（ACN/水、MeOH/水）进行类似的实验，报告每个移动的相体系的流动特性和ζ。在毛细管电色谱（CEC）条件下评价填充毛细管柱（5微米ODS）的流动性和保留稳定性。采用乙腈/水移动的流动相，在13 min内实现了11种多环芳烃的分离。对于最多保留溶质的容量因子（k '）高达4.5的溶质，计算的折合板高（h）在2.5和3.0之间。
Five nonaqueous solvents (acetonitrile, methanol, N,N-dimethylformamide, dimethyl sulfoxide, formamide) and deionized water were investigated for their ability to support electroosmotic flow (EOF) without electrolytic additives. In general, flow was found to be equal to or greater than flow with typical CE buffer systems. The magnitude of EOF was determined for each solvent by open tubular capillary electrophoresis (CE) and related to viscosity (eta), dielectric constant (epsilon), and the ratio of dielectric constant to viscosity (eta/epsilon). Zeta potentials (zeta) were derived indirectly from flow data and tabulated. Comparisons of flow behavior and zeta were made between pure solvents and conventional CE buffers, and questions of equilibrium and reproducibility were addressed. Similar experiments were performed using hydroorganic mobile phases (ACN/water, MeOH/water) across the complete compositional range (100% water-100% organic), with flow characteristics and zeta reported for each mobile phase system. Packed capillary columns (5-microns ODS) were evaluated for flow and retention stability under capillary electrochromatographic (CEC) conditions. A separation of 11 polycyclic aromatic hydrocarbons was performed in under 13 min by CEC with an ACN/water mobile phase. Reduced plate heights (h) were calculated between 2.5 and 3.0 for solutes with capacity factors (k') up to 4.5 for the most retained solute.