Validation of method for the analysis of steels and alloysAuthor(s): G.Swarnabala, N.Saraswati, Y.Praveena
Normally for the analysis of stainless steel (SS), low alloy steel (LAS), aluminium alloy (Al A), brass and white metal standard methods are employed wherein gravimetric, titrimetric and Flame Atomic Absorption Spectroscopy (FAAS) are used. These are generally cumbersome, tedious and laborious to use. Present study describes the use of Standard Materials (SM) and InductivelyCoupled PlasmaOptical Emission Spectroscopy (ICPOES). The digestion procedure is adopted from the standard methods and then the solution was aspirated to ICP-OES. This was an easyway in which thesematerials can be analyzed, in comparisonwith the existing. Themethod was validated by doing repeatable and reproducible experiments. It was established that the analysis done was valid and acceptable within limits of the analysis of these materials. To authenticate the above findings, Inter Laboratory Comparison (ILC) for the validation of this test method has been conducted. The present method of analysis can be implemented only if SM, which takes into account the matrix effect, is available, since no primary standards are used in this field of analysis. However, use of ICP-OES was not uncommon or unacceptable. We have compared the method validation and ILC results inwhich different test methods were employed, to find that the z-scores are lower than 2.0. It may be emphasized that acid dissolution followed by ICP-OES using SM was an authentic way of analysis and was similar to the available methods.