Analysis of different compounds and mixtures is of primary importance. Only with the use of well-established analysis methods can reliably high quality products can be produced. Just think of the importance of the analysis in food industry, where poisonous impurities or content of compounds belonging to different nutritional groups have to be evaluated. Or pharmaceutical industry, where water content can critically affect the delivery of API within the body or very minor impurity, like opposite stereoisomer might add unwanted effects to the drug. All the processes need right analysis methods.
Ionic liquids can be useful in chemical analysis. Most well researched fields include the use of ILs as materials for GC columns with better resolution, application as solvents for GC Headspace, solvents for Karl-Fischer titration, additives for electrophoresis, but also matrices for MALDI-TOF mass spectrometry and solvents for protein crystallization. You can find more information on specific applications following the links below.