GB/T 23985-2009 "Determination of Paints and varnishes vocs (VOC) content, difference method" is a standard issued by the General Administration of mass Supervision, Inspection & Quarantine of China and the National Standardization Administration of China. This standard specifies the method for the determination of vocs (VOC) content in Paints, Coatings and their raw materials. It is mainly applicable to samples with VOC content greater than 15% (mass fraction). For samples with expected VOC content between 0.1% and 15%, the determination should be made with reference to GB/T 23986. This method assumes that the volatile matter is water or organic matter. If it contains Miscellaneous volatile inorganic compounds, it needs to be quantified by appropriate methods and deducted from the calculation. This standard is an important part of the sampling and testing series of Paints, Coatings and related products to ensure accurate determination and control of VOC content in products.