Shortening of Cycle Time in Organic Acid Analysis by Overlapped Injection

Introduction

Organic acids are not only known as acid taste components in foods, but are also used as food additives with antibacterial and antioxidative effects. Pharmaceutical products contain organic acids as counterions of the active ingredient, and analysis of organic acids is carried out to measure the solubility and stability of the active ingredient. Regardless of the field, instruments that enable organic acid analysis with high repeatability in a shorter time are demanded, as large numbers of samples are handled for quality control of products. Use of the ion exclusion mode in HPLC in combination with the post-column pH-buffered electroconductivity detection method enables detection of organic acids with high sensitivity and selectivity. On the other hand, when attempting to achieve high resolution with this technique, detection requires considerable time because two columns are used. In continuous analysis, the overlapped injection of SIL-40 series autosamplers for Nexera™ ultra high performance liquid chromatographs makes it possible to inject the following sample while the preceding sample is being analyzed. This advance injection technique realizes a reduction of the total analysis time in continuous analyses equivalent to the time until elution of the preceding target component. This article introduces an example of shortening of the analysis time in a continuous analysis of organic acids using the overlapped injection of the SIL-40C.

March 31, 2021 GMT