Detection of Surfactants in Waterthinned Coating by PyrolysisGas ChromatographyMass Spectrometry

Based on their pyrolytic characteristics, category of the 3 surfactants i.e. alkylphenylpolyethylene oxide ethers (APEO), normal alkylbenzene sulfonates (NABS) and apliphatic alcoholic sulfates (ALAS) present in waterthinned coating, was detected by pyrolysisGCMS. The waterthinned coating sample was dried at 120 ℃, crushed and extracted ultrasonically with nbutanol. The extract was evaporated to expel the solvent and dried by heating. The menbraneshaped sample thus obtained was used for GCMS analysis after pyrolysis at 600 ℃ for 6 s. It was shown that the pyrolyzates of APEO were alkylphenols and compounds containing monomer of epoxy group; the pyrolyzates of NABS were olefines and homologues of alkyl benzene; and the pyrolyzates of ALAS were SO2, olefines and aliphatic alcohols. The category of surfactants present in the waterthinned coating can thus be determined from the analytical data found by GCMS. Detection limits (3S/N) found for this method were all less than 100 mg·kg-1.