Solvent extraction at high temperture for determination of phthalate esters in cellulose lacquers / Choltira Mahayossanun = การสกัดด้วยตัวทำละลายที่อุณหภูมิสูงสำหรับการตรวจวัดแทเลตเอสเทอร์ในเซลลูโลสแลกเกอร์
Cellulose lacquers is one of the paint used in surface coating furniture and automobile. Phthalate esters are used as the plasticizer in this paint for improves brittle property of film. However, they were suspected to have carcinogenic and estrogenic properties. Reflux is the most commonly used as sample preparation technique for phthalate esters determination in plastic samples, It usually required high amount of sample and solvent. In this study, we aimed to study a sample preparation technique, which required less solvent and extraction time. The solvent extraction at high temperature was investigated for the extraction of phthalate esters from cellulose lacquers paints and determined by gas chromatography. Three phthalate esters, dibutyl phthalate (DBP), di(2-ethylhexyl phthalate) (DEHP) and diisodecyl phthalate (DIDP) were used as solute probes. The effects of types of solvent, ratio of solvent mixtures, ratio between sample and extracting solvent, speed of mechanical stirrer, extraction time and temperature on the extraction efficiency were studied. The ratio of 1:1 between sample to n-hexane with the extraction time of 20 min, extraction temperature of 40ºC and mechanical stirrer speed of 45 rpm were found to be the suitable condition. The recoveries of DBP, DEHP and DIDP at 25ºC were lower than at 40ºC and in range 70-90%. The method of quantification of DBP, DEHP and DIDP were 4.30, 1.10 and 0.70 g/L an relative standard deviation were 12.64, 15.08 and 13.97%, respectively. This studied method was also applied to analyze phthalate esters content in commercialized cellulose lacquer.