Study On Analytical Methods Of Main Toxic And Hazardous Substances In Coatings

Paint as a decorative material,the application is increasingly widespread.With the continuous development of social economy,people began to pursue more functional coatings.In the manufacture of these coatings in the process,often bring a lot of toxic and hazardous substances.These substances are slowly released every day,will cause great harm to the human body.International organizations and government agencies have regulations to regulate volatile organic compounds in coatings.China's mandatory national standards "GB 18582-2008" can check the relevant detection methods and limited conditions.In this paper,the harmful substances in waterborne and solvent-borne coatings were analyzed,and the corresponding detection methods were established,and the actual samples were tested.The major research as follows:1.Determination of volatile organic compounds in waterborne and solvent-borne coatings by gas chromatography-mass spectrometry combined with external standard methodThe content of some organic compounds in the coating samples was analyzed by spectral analysis and mass spectrometry.The detection products of solvent-based coatings were mainly benzene and C9?C11 hydrocarbons,while the water-based paint in the volatile material is relatively little or no.2.A method for the determination of benzene in waterborne and solvent-borne coatings was established by gas chromatography-mass spectrometry combined with external standard method.The qualitative and quantitative analysis was carried out using the retention time and the external standard in the experiment,and the dilution solvent and temperament conditions were discussed.The linear relationship of the experiment is good.The recovery rate is 98.3%?102.5%and relative standard deviation(RSD)is 0.6%?3.4%.The pretreatment of this method is simple,and has the characteristics of fastness,high sensitivity and low detection limit,which can meet the determination and comparison of benzene content in the coating sample.3.The content of free formaldehyde in aqueous and solvent-borne coatings was determined by UV-Vis spectrophotometry.Acetylacetone was used as color reagent and the effect of temperature was discussed.Formaldehyde is linear in the range of 0?100 ?g(r=0.9998).The average recovery of formaldehyde the best for 49.78 ?g,while the experimental RSD are very small and the method is simple,accurate and reliable and widely used to meet the formaldehyde content of 0-0.25 g/kg of various coatings.4.The content of soluble heavy metals in aqueous and solvent-borne coatings was measured by inductively coupled plasma emission spectroscopy(ICP-AES).The experimental results show that the actual content of the sample is lower than the national standard,meet the requirements.