Application Notes: Food and Beverage
Go With the Flow: Thinking About Carrier Gas Flow in Gas Chromatography
March 1st 2020Mobile phase flow is critically important, and must be carefully controlled. In this instalment of “GC Connections”, we discuss carrier gas flow and its importance in successful gas chromatographic (GC) analysis. We will begin with a short review of fundamental theories showing why flow is important, and move into a discussion of how flow rate is measured and controlled on modern instruments. Finally, we will discuss the effect of flow-related parameters, including carrier gas choice, the difference between constant pressure and constant flow modes, and some new thinking about flow rate optimization. We conclude with some takeaways that should assist gas chromatographers with effective carrier gas management.
SEC-MALS Analysis of Linear and Branched Synthetic Amyloses
March 1st 2020Amylose is an occasionally branched biopolymer and, together with amylopectin, the hyper-branched component, a constituent of starch. Determination of branching in amylopectin, an important property affecting viscosity, stiffness, and thermo-mechanical performance, requires a fully linear amylose analogue. This application note describes how synthetic amyloses from enzymatic (phosphorolytic) reaction were checked for their linearity using size-exclusion chromatography-multi-angle light scattering (SEC-MALS).
GC×GC Analysis of Environmental Samples
December 10th 2019-GC×GC offers dramatic improvements over traditional gas chromatography for the analysis of complex mixtures in numerous applications -The power and utility of GC×GC technology -The need for more advanced and novel stationary phases for gas-chromatographic columns