LCGC North America-05-01-2017

Derringer desirability functions are a great favorite of mine because they are very simple and flexible. They may be applied to a variety of problems: whenever you need to select the “best” (sample, method, operating conditions etc.) from a set. It is also a convenient way to compare apples and oranges, whenever totally unrelated features must be ranked. They were first described by Derringer and Markham1 to select polymeric materials based on varied properties.

What is required to optimize a gradient elution HPLC method?

A surfactant based diluent was used in sample preparation for reversed phase HPLC analysis of a drug product and its impurities in a phospholipid formulation. The use of the didodecyl trimethylammonium bromide (DDAB) enabled a consistent, quantitative extraction of the analytes of interest from the lipid matrix in a much more aqueous, weak solvent. Water was added as an anti-solvent to precipitate out the surfactant from the system to eliminate HPLC injection pressure spikes, enabling large volume injections and achieving a consistent, robust method for long term use. Method development and validation steps are described.

Several variables can be used to change selectivity in a liquid chromatographic (LC) separation. Here we compare the variables in an effort to prioritize which experiments will be most effective.

This yearly report on new products introduced at Pittcon 2017 (or in the preceding year) covers sample preparation instrumentation, supplies, and accessories.

Annual review of new developments in the field of GC

Eric Nelson discusses methods for analyzing halogenated transformation products of pharmaceuticals and other contaminants.

How does the career of a young leader get started?

Reflections on a career blending academia and entrepreneurship

Click the title above to open the LCGC North America May 2017 regular issue, Vol 35 No 5, in an interactive PDF format.