This International Standard specefies a gas-chromatographic method for determining monomeric diisocyanates such as toluene diisocyanate1), hexamethylene diisocyanate, isophorone diisocyanate2), diphenylmethane diisocyanate3) and other diisocyanates in isocyanate resins as defined in clause 3 and solutions prepared from such resins, insofar as these are used formulation of paints and similar coating materials.