毛细管柱气相色谱法测定橡胶树胶乳中的乙烯含量及其变化

Determination of rubber latex ethylene content and its variation by capillary gas chromatography

采用毛细管柱气相色谱法测定橡胶树胶乳中的乙烯含量,并初步测定了乙烯刺激割胶不同割次的乙烯含量及其变化.该方法的线性范围为11.6-581.4μL.L-1,检测限为1.12μL.L-1,相对标准偏差(RSD)为1.01%.橡胶树采用乙烯利刺激(S/2 D/2+2.5%ET),涂药后第1-3割次的胶乳乙烯释放量分别为:151.6、31.1、17.5μL.L-1,而未经刺激的橡胶树(对照)乙烯含量低于检出限;第1-3割次的胶乳乙烯生成速率分别为:2.823、0.578、0.324 nL.g-1.h-1,表明经乙烯利刺激后,胶乳中的乙烯含量大量增加,生成速率发生了明显变化,均大于对照,且随割次的增多而降低.

A new determination method for ethylene content in latex of rubber tree（Hevea brasiliensis） by capillary gas chromatography（GC） was studied,and the ethylene content and its variation in latex were preliminarily determined from the different tapping under ethrel stimulation.It was showed that the RSD of ethylene in latex was 1.01%,the detectable level of ethylene in latex was 1.12 μL·L^-1nd the linear range of ethylene in latex was 11.6-581.4 μL·L^-1y means of Shimadzu GC2010 GC.After treating with 2.5% ethrel stimulant（S/2 D/2＋2.5% ET）,the ethylene release rates of latex from the first to the third tapping were 151.6,31.1,17.5 μL·L^-1espectively,and the ethylene production rates of latex from the first to the third tapping were 2.823,0.578,0.324 nL·g^-1·h^-1 respectively,but the ethylene release rate,which was lower than the detectable level,could not be detected in the control without stimulation.The experiment indicated that,after stimulating with ethrel,in latex there were significant changes in ethylene release rate and production rate,which were both higher than those of the control,and they obviously decreased as the increasing of tapping time.