In the process of analysis, the impurity interference, organic matter or metal ions in the sample will pollute the packings of column, reduce the separation ability and service life of the column, and the impurity ions will interfere with the separation of ions. So the sample pretreatment column should be used. It can effectively remove the organic matter and impurity ions in the sample, avoid the contamination of impurities on the column and the influence on the separation effect, effectively prolong the service life of the column and improve the separation effect of the sample.