GC-MSD和GC-SCD在聚合级烯烃原料中痕量硫化物的分析应用

采用闪蒸同步气化进样系统和动态气体稀释系统,建立了聚合级烯烃原料中微量硫化物的GC-质谱检测器(MSD)和GC-硫化学发光检测器(SCD)分析方法。实验结果表明,采用惰性毛细管色谱柱和MSD/SCD检测器,能实现硫化氢、羰基硫和甲硫醇的高效分离和检测。闪蒸同步气化系统较好地解决了气体同步气化和气化后气态硫化物二次冷凝的问题;动态气体稀释系统简化了外标校正曲线的绘制。当硫化物含量在0.022~9.80 mL/m³时,外标校正曲线相关系数大于0.999,硫化物的加标回收率为96.1%~112.4%,相对标准偏差小于5.0%,最低检出限为0.011~0.015 mL/m³。本工作建立的方法满足实际聚合级烯烃原料中硫化物含量的监测和分析要求。

Determination of trace amount of sulfides in polymer grade olefin feedstock by GC-MSD and GC-SCD methods

Trace amount of sulfides in polymer grade olefin feedstock has been determined by GC with mass selective detector(MSD)and GC with sulfur chemiluminescence detector(SCD)with the introduction of a liquid evaporator and a gas dynamic dilution system.The results show that hydrogen sulfide,carbonyl sulfide and methyl mercaptan can be effectively separated and determined by MSD/SCD with the installation of a kind of inert capillary columns.The introduction of liquid evaporator can help simultaneous gas evaporation and prohibit the re-liquefaction process of gaseous sulphur compounds;and the gas dynamic dilution system is able to greatly simplify the process to establish the external standard calibration curve.The correlation coefficients of standard curve are all above 0.999,while the recoveries of samples being between 96.1%to 112.4%,the relative standard deviation being less than 5.0%and the lowest detection limit being appropriate at 0.011-0.015 mL/m³ when the content of sulfides in the feedstock ranges 0.022-9.80 mL/m³.The method described hereby can reach the request of customers to determinate and analyze trace amount of sulfides in polymer grade olefins.