Rapid determination of free formaldehyde in water-based coatings and adhesives by headspace-gas chromatography-mass spectrometry

The method was developed for rapid determination of free formaldehyde in water-based coatings and adhesives by head space-gas chromatography-mass spectrometry.After the sample was completely dissolved in water,it was positioned to headspace sampling instrument and heated at 80 ℃ for 20 minutes for a distribution equilibrium of formaldehyde between gas and liquid phases.The headspace gas was extracted and injected into gas chromatograph for analysis with selective ion mode of mass spectrometry(MSD).Formaldehyde was separated from air and other interference substances by the capillary column of PLOT/Q.Retention time and fragment ions abundance ratio were used for qualitative analysis,and external standard method was applied to quantitation.The results showed that the linear range was 1.0 ~ 100.0 mg/L with the linear equation of y = 448.9777 x + 16.6253 and correlation coefficient of 0.9997.The detection limit was 5 mg/kg.The recoveries were 91.3% ~ 96.7% and relative standard deviations(RSDs)(n = 6) were 1.3% ~ 2.1%.This method is simple,rapid and repeatable,which is applicable for rapid analysis of free formaldehyde in water-based coatings and adhesives.