采用气相色谱法,以二氯二苯三氯乙烷(DDT)为参考化合物,测定了6个多溴联苯(PBBs)在不同温度条件下的蒸气压,然后使用Slide数理统计软件、以最小二乘法回归计算出Antoine方程的A,B,C参数,从而建立了6个PBBs的蒸气压与温度的关联式。初步探讨了分子连接性指数与蒸气压的相关性,结果发现一阶拓扑指数与蒸气压表现出很好的线性关系,两者的相关系数的平方大于0.99,标准偏差小于0.08。
Polybrominated biphenyls (PBBs) are a class of new type organic pollutants. They have been widely used as flame retardants to reduce the fire risk on plastics, carpets, electronic equipment, textiles and building materials around the world. With a gas chromatographic retention time technique, vapor pressures (p) of six polybrominated biphenyls (PBB15, PBB25, PBB31, PBB49, PBB103 and PBB153) were determined as a function of temperature with dichlorodiphenyl trichloroethane (DDT) acting as a reference substance. Vapor pressures at 298. 15 K ranged from 0.01 Pa for dibrominated biphenyl to 10^-6 Pa for hexabrominated biphenyl. According to these vapor pressures at different temperatures, Antoine parameters (A, B, C) of six PBBs were regressed with the least square method. The correlations between vapor pressure and temperature for six PBBs were obtained. In addition, the correlations between vapor pressures and molecular connectivity indexes have been studied with correlation coefficients greater than 0.99 and standard errors less than 0.08. The vapor pressures of PBBs were also estimated by their molecular connectivity indexes.