Peak Shape Improvement Using the Auto-Pretreatment Function (Co-injection) of i-Series Plus Integrated Liquid Chromatograph

Introduction

Ultra-high performance liquid chromatography (UHPLC) requires a system with even lower dispersion than that of conventional high performance liquid chromatography (HPLC). In addition, the UHPLC system commonly employs tubing with an inner diameter of 0.1 mm or less. This is because the internal diameter of columns used for UHPLC systems is small with 2.0 to 3.0mm being the most popular and therefore more prone to be affected by extra- column dispersion compared to HPLC. However, smaller internal diameters in tubing mean that mixing of the sample and mobile phase within tubing becomes difficult. If the sample solvent is organic and has a higher concentration than that of the mobile phase, the solvent may affect the sample dispersion at the column and result in broad peaks. The small I.D. of the column emphasizes this phenomenon. This article introduces a case where peak shape was improved by using the automatic pretreatment function (co-injection) of the i-Series Plus model Nexera-i MT to automatically mix the sample together with the dilution solvent and then perform analysis.

May 23, 2018 GMT