Direct Determination of Trace Impurities in Colloidal Silica by ICP-AES with Direct Sample Introduction

Colloidal silica was homogeneously dispersed in water medium by ultrasonic vibration without any other stabilizing agent added. The suspension was introduced into an ICP and then analyzed directly by AES. Precision and accuracy of the method are satisfactory in comparison with those from the method of conventional wet decomposition. The method,which permits the direct analysis of colloidal silica samples,is quite simple and convenient due to the sample pretreatment time being largely shortened. Furthermore,it greatly reduces pollution hazard to environment since the sample decomposition by HF pretreatment has been saved.