顶空-气相色谱法测定正戊烷-异戊烷发泡体系聚合珠粒挥发出易燃气体体积分数

Headspace Gas Chromatography Determination of Volatile Flammable Gas Volume Fraction of Polymerized Beads From an n-Pentane-isopentane Foaming System

建立顶空-气相色谱测定可发泡聚合珠粒挥发出戊烷气体体积与空气体积比的方法,确定气相色谱条件。聚合珠粒在密闭容器内经50℃存放14天后得到待测气体样品,直接上机分析,外标法定量。结果表明:正戊烷和异戊烷均在0.034%~1.087%范围内线性关系良好(R^(2)=0.9999),仪器检测限正戊烷0.00315%(S/N=3)、异戊烷0.00603%(S/N=3),在高、中、低3个加标水平下,对样品进行加标回收实验,正戊烷平均回收率在99.5%~100.7%,相对标准偏差在0.60%~0.86%,异戊烷平均回收率在98.2%~100.7%,相对标准偏差在0.86%~1.21%。本方法具有方便、快速、灵敏度高等优点,可用于可发泡聚合珠粒挥发出戊烷气体体积分数的测定。

A determination method of volume fraction of pentane gas evaporating from foamable polymeric beads by headspace-gas chromatography was proposed,the gas chromatographic conditions were determined.After polymeric beads were stored in a closed container at 50℃for 14 days,the obtained gas sample was measured on the instrument directly and quantitatively using the external standard method.According to the results,both n-pentane and isopentane showed a good linear relation in the range of 0.034%~1.087%(R^(2)=0.9999).The detection limit of the instrument was 0.00315%for n-pentane(S/N=3),and 0.00603%for isopentane(S/N=3),and the spike recovery test was conducted respectively in the case of high,medium or low fortified volume fractions.The results showed that the average recovery rate of n-pentane was 99.5%~100.7%,and the relative standard deviation was 0.60%~0.86%.The average recovery rate of isopentane was 98.2%~100.7%,and the relative standard deviation was 0.86%~1.21%.The proposed method is convenience,rapidity,high sensitivity,so it can be used to determine the volume fraction of the pentane gas evaporating from foamable polymeric beads.