CHEMICAL-ANALYSIS OF PORTLAND-CEMENT BY INDUCTIVELY-COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

A methodology has been developed which applies ICP-AES to the determination of Ca, Si, Al, Fe, S, Mg, K, Ti, Na, Sr, Mn, Zn and Cr in Portland cement. The samples were solubilized through fusion with LiBO2 in a graphite crucible with subsequent dissolution in 5% V/V HCl. For quantification of sulphur an indirect approach was chosen, namely sample fusion with Na2CO3-KNO3 and subsequent extraction of water. Short term and method precision of the determination of the major elements were tested, a considerable improvement being observed when yttrium was used as internal standard. Accuracy of the proposed method was tested analyzing several samples of NBS-SRM Portland cement.