Headspace GC analysis is used to measure the residual solvents in a compound.  This instrument runs a generic validated method which covers the vast majority of the ICH class 2 and 3 solvents and is compatible with most of the compounds Onyx makes.  Bespoke methods are also developed for specific projects (e.g. PGI analysis).  Direct injection GC is also available for monitoring of less volatile solvents and other reagents or intermediates for which LC analysis is not appropriate.