Certified reference materials (CRM) are commercially available primarily in two forms:
as pure substances or solutions with a strictly defined concentration. The choice of solvent used in the solution mainly results from the physicochemical properties of the substance (e.g. solubility) and the limitations of the research method.
MUCH DEPENDS ON SOLVENT
It happens that there are standard substances in solutions that do not guarantee the overall stability of the sample. A good example is pesticide amitraz sold in methanol solution which when heated at a high temperature, that is in column inlet of the gas chromatograph, is degraded. This standard of amitraz – prepared in methanol – is dedicated only to measurements using a special adapter spectrometer GC (purge – trap techniques). This adapter is not normally mounted with devices, which can be a problem in some laboratories. For example, the same pesticide in acetonitrile solution is stable – so it can be injected into devices by standard injection. So you can see that the choice of solvent used in the solution standards can easier or hinder a work on analysis of substance.
Because of that we offer our customers the standard solutions of certified reference materials in these solvents, they are able to analyze the methods available in most laboratories.