Ascentis® Express RP-Amide HPLC Columns

Sialic acids are important because they affect bioavailability, function, stability, and metabolism of glycoproteins. A new HPLC method employing an Ascentis® Express RP-Amide column was developed to determine DMB-labeled NGNA and NANA sialic acids released from biotherapeutic proteins. This article explains the many advantages this method offers over the original C18 method.

This application note demonstrates the use of two Ascentis® Express columns for the analysis of beverages. Two column chemistries, RP-Amide and HILIC, both amenable to the analysis of polar compounds, were successfully used to resolve several beverage components, including sugars, vitamins, sweeteners, preservatives, and caffeine.

LC-MS/MS methods are very popular for the analysis of pesticides in food. Several methods currently exist for their extraction from a variety of different food matrices. One of the newer methods is known as the QuEChERS, this method employs dispersive solid phase extraction (SPE) for extraction and cleanup. This method is now the European Norm (EN 15662). While this method typically uses C18 HPLC columns, this application note describes an intra-laboratory comparison and validation procedure using an Ascentis® Express RP-Amide column.

This application compendium presents a series of technical articles covering forensic, clinical, and bioanalytical applications. Topics include SPME of VOCs in Breath, Analysis of Vitamin D Metabolite Critical Pairs in Serum, Chiral LC-MS of Methamphetamine, and more.

Thyroid hormones play critical roles in the regulation of biological processes such as growth and brain development. For the clinical laboratory, measurements of total T4 and total T3, along with estimates of free T4 and free T3 are important for the diagnosis and monitoring of thyroid diseases. An online SPE/LC-MS method was developed for the determination of the thyroid hormones T4, T3, and rT3 from plasma using Ascentis® Express RP-Amide cartridge to trap the analytes, and an Ascentis® Express Phenyl-Hexyl column to resolve them.

Much is known regarding the genome of Neurospora crassa, specifically in the determination of circadian rhythms. However, little is known regarding how the metabolome changes over the course of the day under control of the circadian clock. Profiling metabolic changes in biological samples can be a complex and tedious task. The use of the high-resolution Ascentis® Express HPLC columns greatly aids in the resolution of components in even the most complex sample matrix.