Method for measuring content of free formaldehyde in coating or adhesive through gas chromatography

The invention discloses a method for measuring the content of free formaldehyde in coating or an adhesive through gas chromatography. The method comprises the steps: a pre-column derivatization meansis adopted, the coating or the adhesive is subjected to sample weighing, diluted, and then subjected to a heating reaction together with an acetylacetone solution with the pH being 6 to generate 3-methylene-2,4-pentanedione, after being extracted through ethyl acetate, the 3-methylene-2,4-pentanedione is detected through the gas chromatography, and the content of the formaldehyde is calculated qualitatively by the appearance time and quantitatively by the peak area. The problems that in the distillation process of acetylacetone through spectrophotometry, the time is long, airtightness is poor,the formaldehyde overflows, then the detection result is slightly low, or the condensed formaldehyde is very prone to being dissociated due to the high temperature in the distillation process, thus the detection result is sli