Reducing matrix effect error in EDXRF: comparative study of using standard and standardless methods for stainless steel samples
Abstract
Abstract
Even though EDXRF analysis has major advantages in the analysis of stainless steel samples such as simultaneous determination of the minor elements, analysis can be done without sample preparation and non-destructive analysis, the matrix issue arised from the inter element interaction can make the the final quantitative result to be in accurate. The paper relates a comparative quantitative analysis using standard and standardless methods in the determination of these elements. Standard method was done by plotting regression calibration graphs of the interested elements using BCS certified stainless steel standards. Different calibration plots were developed based on the available certified standards and these stainless steel grades include low alloy steel, austentic, ferritic and high speed. The standardless method on the other hand uses a mathematical modelling with matrix effect correction derived from Lucas-Tooth and Price model. Further improvement on the accuracy of the standardless method was done by inclusion of pure elements into the development of the model. Discrepancy tests were then carried out for these quantitative methods on different certified samples and the results show that the high speed method is most reliable for determining of Ni and the standardless method for Mn.
Abstrak
Walaupun analisis EDXRF mempunyai beberapa kelebihan didalam menganalisis keluli seperti boleh menentukan unsur surihan secara spontan, analisis boleh dibuat tanpa penyediaan sampel dan teknik analisis tanpa rosak, isu matriks dari interaksi antara unsur boleh menyebabkan analisis akhir kuantitatif menjadi tidak tepat. Kertas kerja ini menerangkan satu kajian kuantitatif perbandingan mengguna piawai dan tanpa piawai bagi menentukan unsur-unsur ini. Kaedah piawai dilakukan dengan melakar geraf kalibrasi secara regression bagi unsur-unsur yang dikehendaki menggunakan piawai keluli dari BCS. Geraf-geraf kalibrasi bagi keluli jenis low alloy steel, austentic, ferritic dan high speed telah dibangunkan melalui kaedah ini. Kaedah tanpa piawai pula melibatkan penggunaan model mathematik yang menggurangkan kesan matriks menggunakan model Lucas-Tooth and Price. Penambaikkan bagi model ini dilakukan melalui penggunaan unsur-unsur tulen bagi meningkatkan ketepatan analisis. Ujian perbezaan kemudiaannya dilakukan bagi berapa sampel piawai dan hasil darinya didapati kaedah high speed adalah terbaik bagi unsur Ni manakala kaedah tanpa piawai adalah terbaik bagi unsur Mn.
