离子色谱法测定油田回注水中季铵盐的含量

建立了油田回注水中痕量季铵盐的离子色谱分析方法.对回注水用滤膜和RP柱预处理,选用Ion Pac CS12A阳离子交换色谱柱、20 mmol/L甲烷基磺酸淋洗、抑制型电导检测,在17.4～19.6 min之间分离测定了季铵盐阳离子表面活性剂的含量,并解释了随着季铵盐浓度的增大,保留时间变小的实验事实.该方法具有良好的线性关系(r=0.999 7)和精度(测定组分峰面积的相对标准偏差(n=5)在6.0%以下),回收率在104.2%～107.3%之间,最小检测限为0.27 mg/L.该方法操作简单、方便,结果准确可靠.

Determination of the content of quaternary ammonium salt in oilfieid reinjection water by ion chromatography

A method for the determination of trace quaternary ammonium salt in recycled injection water in oilfields by ion chromatography is presented.The recycled injection water is pre-treated by using membrane filtration and RP column.The separation of quaternary ammonium salt is finished by using an Ion Pac CS12A column and methanesulfonic acid of 20 mmol/L as eluent.Cations are detected by suppressed conductivity detection.The fact is found that in the range of 17.4~19.6 min,the higher the concentration of quaternary ammonium salt is,the shorter the retention time is.The fact is explained.There is good linearity between the content of quaternary ammonium salt and peak area in the determining method(r=0.999 7).this method has high measuring precision (the relative standard deviation of measuring the peak area is less than 6.0%).The measuring recovery rate of the method is 104.2%~107.3%,and the minimum detectable level is 0.27 mg/L.The operation of this method is simple.