Mary Ellen P. McNally | Authors


Chromatography Advances at EAS 2020

The 2020 Eastern Analytical Symposium has gone virtual for 2020, and although we will miss the camaraderie of face to face interaction, the theme of this year’s conference “Analytical Science: Cornerstone of Innovation” indicates the strength of the separation sciences and the talks that you will not want to miss.

Precision of Internal Standard and External Standard Methods in High Performance Liquid Chromatography

Internal standard methods are used to improve the precision and accuracy of results where volume errors are difficult to predict and control. A systematic approach has been used to compare internal and external standard methods in high performance liquid chromatography (HPLC). The precision was determined at several different injection volumes for HPLC and ultrahigh‑pressure liquid chromatography (UHPLC), with two analyte and internal standard combinations. Precision using three methods of adding the internal standard to the analyte before final dilution was examined. The internal standard method outperformed external standard methods in all instances.