Measurement and Modeling of Extra-Column Effects Due to Injection and Connections in Capillary Liquid Chromatography

Chromatography

James P. Grinias¹  Bernard Bunner²  Martin Gilar²  James W. Jorgenson¹ 

[1] Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA; E-Mail:;Waters Corporation, Milford, MA 01757, USA; E-Mails:

关键词: extra-column band broadening;    injection;    liquid chromatography;    peak measurements;   

DOI  :  10.3390/chromatography2040669

来源: mdpi

【 摘 要 】

As column volumes continue to decrease, extra-column band broadening has become an increasingly important consideration when determining column performance. Combined contributions due to the injector and connecting tubing in a capillary LC system were measured and found to be larger than expected by Taylor-Aris theory. Variance from sigma-type and tau-type broadening was isolated from eluted peaks using the Foley-Dorsey Exponentially Modified Gaussian peak fitting model and confirmed with computational fluid dynamics. It was found that the tau-type contributions were the main cause for the excessive broadening because of poorly-swept volumes at the connection between the injector and tubing. To reduce tau-type contributions (and peak tailing), a timed pinch mode could be used for analyte injection.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.