气相色谱法测定涂料和胶粘剂中游离甲醛含量

Determination of free formaldehyde in coating and adhesive by gas chromatography

采用水性涂料、胶粘剂称样稀释至一定稀释倍数,吸取定量的样品溶液,加入一定体积pH=6的乙酰丙酮溶液加热显色后冷却至室温,采用乙酸乙酯萃取后稀释至规定刻度,气相色谱法检测,以3-亚甲基-2,4-戊二酮出峰时间定性、峰面积定量计算甲醛含量。研究结果表明:使用此方法测定涂料的检出限为0.6 mg/kg,胶粘剂的检出限为6 mg/kg;同一操作重复性≤1%,不同人及实验室的再现性为≤9%,可信度为99%;12个不同种类的样品加标检测后,加标回收率为93.6%~103.6%,认定本方法的准确性较高。

The water-based coating and adhesives were used to dilute to a certain dilution ratio.The quantitative sample solution was absorbed and added to a certain volume of acetylacetone solution with pH=6,and heated for color development,then cooled down to room temperature,and extracted with ethyl acetate and diluted to the specified scale,then detected by gas chromatography.The formaldehyde content was calculated qualitatively by the peak time and quantitatively by the peak area of 3-methylene-2,4-pentanedione.The research results showed that the detection limit of coating was 0.6 mg/kg,and the detection limit of adhesive was 6 mg/kg.The repeatability of the same operation was less than 1%,the reproducibility of different people and laboratories was less than 9%,and the reliability was 99%.After 12 different kinds of samples were tested,the recovery rate was 93.6%~103.6%,which indicated the accuracy of this method was quite high.