Investigation On Determination Methods Of Volatile Organic Compounds In Paint

Paint as a kind of decorative and functional material has been widely used in the areas of industry and life. With the people's awareness of environmental protection and health, the safe use of paint has became the focus of attention. The source of harmful substances in paint, such as: raw materials, production of chemical treatment, various additives.The raw materials and additives has released harmful substances to environment, for example: formaldehyde, alcohol, volatile halohydrocarbons, benzene homologues, toluene diisocyanate, hexane diisocyanate and volatile organic compounds, etc.The main components of VOCs consists of hydrocarbons, oxygen hydrocarbons, halogen hydrocarbons, nitrogen and sulfur hydrocarbons and other hydrocarbons. Because of its complex composition, the harmful substances has shown toxicity, irritation, carcinogenicity and special smell, the harmful substances can lead human to discomfort response, and it can a serious impact to human health and the environment. So, in 1977 Clean Air regulations had developed the U.S. Environmental Protection Agency (EPA), it restricted to 189 kinds of harmful solvent emissions(methanol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, etc). As early as 2001, the VOCs content of the coating has restricted to the limit of harmful substances, not only VOCs detection methods have been revised, but also lower limited. But now research of VOCs (alcohol, benzene, halogenated hydrocarbons, butyl ether class, free diisocyanate and acetate esters)compounds has few detected.The GC-MS method for the determination of volatile organic compounds (VOCs) in the coatings has been developed. In order to solve the disadvantages of poor separation and low recovery of current method. The establishment of this method can not only meet the rapid detection of import and export needs but also for people's health and environment protection in China has great significance.The conclusions in this thesis are included as follows: 1.The GC-MS method for the determination of 24 kinds of volatile organic compounds (alcohol, benzene homologues, monobutyl ether and acetic ester) in the interior coatings has been developed. In order to solve the disadvantages of poor separation and low recovery of current method, we have developed a new procedure which was purified by anhydrous sodium sulfate, sonicated in dichloromethane to extract the substances in matrixes. Higher recovery has been achieved by using our method, especially the recoveries of diols compounds. The recoveries varied from 70% to 94% with relative standard deviations(RSDs) not more than 6.8%.The detection limit range from 3.1 mg/L to 10.6 mg/L. The calibration curves were linear in the range of 30 ~300 mg/L with correlation coefficients higher than 0.99.2.The GC-MS method for the determination of 16 kinds of harmful substances(methanol, volatile halohydrocarbons, benzene homologues, the free of toluene diisocyanate and hexane diisocyanate) in the solvent based coatings was developed. Extraction and separation of compounds by using organic solution of ethyl acetate, n-hexane, tetrahydrofuran and acetonitrile was researched. Procedure of sample pre-treatment and condition of instruments was optimized, the concentration of compounds were quantitatively determined with 2-Bromopropane and 1,2,4-Trichlorobenzene as internal standard, and acetonitrile as extraction reagent.The internal standard method was used for quantitative analysis. In the concentration range was from 5 to 200 mg/L, the linear relationship of the method was very well and correlation coefficients was greater than 0.99. The recovery range was varied from 80.2% to 105.0%, the relative standard deviations were less than 5.0%. The detection limit range was from 0.08 mg/ to 1.41 mg/L.The innovation in this thesis are included as follows:1.The GC-MS method for the determination of 24 kinds of volatile organic compounds (alcohol, benzene homologues, monobutyl ether and acetic ester) in the interior coatings has been developed. Extraction and separation of compounds by using organic solution of acetonitrile, tetrahydrofuran, ethyl acetate and dichloromethane was researched, and dichloromethane as extraction reagent.The impact on the recovery of anhydrous sodium sulfate was researched. Higher recovery has been achieved by using our method, especially the recoveries of diols compounds.2.The GC-MS method for the determination of 16 kinds of volatile organic compounds (methanol, volatile halohydrocarbons, benzene homologues, the free of toluene diisocyanate and hexane diisocyanate) in the solvent based coatings was developed. Extraction and separation of compounds by using organic solution of ethyl acetate, n-hexane, tetrahydrofuran and acetonitrile was researched. Procedure of sample pre-treatment and condition of instruments was optimized. Discussion of internal standard compounds, 2-Bromopropane and 1,2,4-Trichlorobenzene as internal standard, and acetonitrile as extraction reagent.