5A分子筛络合低含量正构烷烃湖泊沉积物的方法优化

Optimization the Complexing Method with 5A Molecular Sieve for Low Content n-Alkanes in the Lake Sediment

摘要: 传统5A分子筛吸附混合溶剂洗脱正构烷烃的方法适用于正构烷烃含量中–高水平的湖泊沉积物样品，而沙漠湖泊岩芯样品中正构烷烃含量远低于一般湖泊沉积物。此类样品用传统的5A分子筛方法络合洗脱，正构烷烃的回收率仅为0%~32.86%。本文对已有的5A分子筛吸附混合溶剂洗脱方法进行优化，具体为：将低含量母液和对应量分子筛加入可密封玻璃瓶中后用环己烷对正构烷烃进行络合，可密封玻璃瓶中的液面高度由原先的2 cm降低至1 cm。优化后的方法可获得93.96%~100%的络合回收率。

Abstract: The classical method of 5A molecular sieve for absorbing mixed solvents to elute n-alkanes is suitable for samples with medium to high content levels of n-alkanes, but the content of n-alkanes in the desert lake sediment core is lower than that from general lake sediments. The recovery rate of samples with medium to high content levels content complexed and eluted by the classical 5A molecular sieve method is only 0% - 32.86%. In this article, we optimize the classical 5A molecular sieve adsorption mixed solvent elution method, specifically: adding a low content of mother liquor and the corresponding amount of molecular sieve into a sealable glass bottle to complex n-alkanes with cyclohexane. Liquid level in sealable glass bottle reduced from 2 cm to 1 cm. The optimized method can obtain 93.96% - 100% complex recovery rate.