Development of an Automated Sample Injection System for Pillar Array Columns

Abstract

A pillar array column with a perfectly ordered internal structure has a higher separation efficiency than a particle-packed column used in conventional high-performance liquid chromatography. However, applying the pillar array column technology to quantitative analysis is challenging as the injection volume of the sample varies for each injection. This occurs because the sample volumes are in the order of nanoliters and the sample is injected manually. In this study, an automated sample injection system was developed to solve this problem. The system was composed of two pumps (one for the sample and other for the mobile phase), a six-way valve that can be controlled by a PC, and an autosampler. The peak height deviation, which is more than 20% in the conventional manual injection system, was improved to 1.2% and 0.4% for the two coumarin dye samples. This result indicated that the automated sample injection method developed in this study could be applied to pillar array columns to allow for quantitative analysis.

On-Chip Liquid Chromatography

“…The feasibility of quantitative analysis of samples using pillar array columns with the help of an internal standard was demonstrated. Furthermore, an automated sample injection system for pillar array columns was developed to maintain a constant sample injection volume [29]. The system was composed of two pumps (one for the sample and another for the mobile phase), a six-way valve that can be controlled by a PC, and an autosampler.…”

Molecular Shape Selectivity for Polycyclic Aromatic Compounds on a Poly(benzoguanamine-<i>co</i>-melamine-<i>co</i>-formaldehyde) Stationary Phase in Reversed-Phase Liquid Chromatography

“…Liquid chromatography (LC) is one of the most powerful and convenient separation methods, especially for the separation of non-volatile sample matrix in separation science [1][2][3][4]. In order to obtain an effective separation of the complex sample mixtures commonly encountered in actual separation problems, the stationary phase plays an essential role [5][6][7][8].…”

Improvement of an Automated Sample Injection System for Pillar Array Columns to Increase Analytical Reproducibility

“…However, the separation efficiency of such columns is limited because the particles cannot be packed perfectly and uniformly [ 7 , 8 ]. To overcome this problem, pillar array columns with a completely uniform internal structure and regularly arranged microsized pillars have recently been developed [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Pillar array columns can significantly reduce eddy diffusion and lead to better resolution than particle-packed columns do.…”

“…However, owing to the requirement of a small amount of sample (approximately 1 nL) to be injected, accurate control of the injection volume is difficult, which limits the use of pillar array columns for quantitative analysis. Thus, an automated sample injection system that can provide a constant sample injection volume has been developed for the quantitative analysis of biological samples using pillar array columns [ 11 ]. The constant sample injection volume is maintained by introducing an autosampler to the system.…”