Sample Preparation

Frequently asked questions related to the application of DLS to the characterization of protein therapeutic formulations

GPC/SEC can be used to characterize commodity or bulk manufactured polymers. Here we describe how the use of formic acid instead of hexafluoroisopropanol (HFIP) as the dissolution solvent and/or mobile phase can lead to improvements in both cost per analysis and health and safety. 

Rheology is the science of material flow. It is also a science with a reputation for some fairly daunting mathematics. But look past these first principles and rheology has immediate relevance in formulation which is readily appreciated and easily exploited.

This application note describes a solid phase extraction (SPE) protocol for the extraction of a range of mycotoxins from dried chili (pimiento) using ISOLUTE® Myco with LC-MS/MS analysis.

The chemical analysis chain is only strong if the quality system takes into account each and every link – including those that can sometimes be neglected or forgotten.

Having attended Pat Sandra’s lecture at Riva 2014 and read The Analytical Scientist’s feature on sample preparation, I can certainly say that Pat has succeeded in igniting discussion on the topic. Here’s my silver Sickle’s worth.

Whey is a by-product of the cheese-making process, and Whey Protein Isolate (WPI) is a dietary supplement and food ingredient created by separating components from milk. It contains a high percentage of pure protein and can be pure enough to be virtually lactose free, carbohydrate free, fat free, and cholesterol free. In this application note, a sample of WPI was characterized using the Viscotek TDAmax. The 4 main components in this mixture were separated and individually characterized.

This application note presents an example of how calorimetry aided the formulation development for ProX by providing insight into excipient-protein interactions. Polysorbate-80 and phenol are examined here as potential additives to the formulation buffer for ProX.

Analytical QbD (AQbD) promises to extend the rigor and benefits of QbD into the area of analytical method development.

Many sample preparation techniques originated a long, long time ago. Should we be satisfied with old separation magic or does our whole approach need to be re-cast?