X-ray fluorescence (XRF) spectrometry is used extensively for the analysis of a wide range of oxide materials with oxide concentrations ranging from a few ppm to 100 wt%. Simple sample preparation, high accuracy and precision are the major benefits of the XRF technique. Accurate analysis is increasingly important for many reasons, including superior production, process and grade control, with associated cost savings, minimizing and controlling contamination and environmental pollution and quality control of products.
WROXI is a set of primary, synthetic standards that can be used to set up universally applicable, wide-range oxide fused bead calibrations. WROXI calibrations can be used directly to monitor production, but also to provide traceability for pressed powder applications calibrated with in-house standards.
Zetium, together with the WROXI application module and our SuperQ analytical software with our advanced Fundamental Parameters (FP) algorithm, provides the ultimate solution for the analysis of a wide range of materials. In this data sheet the analysis of certified reference material (CRM) GBW 07105 highlights the performance of Zetium with respect to stability and precision.
Malvern Panalytical's range of Zetium XRF spectrometers can be configured with power settings ranging from 1 to 4 kW. This data sheet was prepared with data generated by a system configured with 1 kW power. The system includes an X-Y sample handler for unattended batch analysis and advanced analytical software. The system is engineered for excellence in terms of analytical accuracy, precision and operational performance.
The WROXI application module comprises 19 synthetic, multi-element standards. Made from traceable compounds WROXI is a primary analytical solution. The standards are delivered as powders to be prepared as fused beads on-site, using the customer’s flux, dilution ratios and methodology. They can therefore be tailored to suit the needs of different laboratories.
Sample preparation and measurement details
The WROXI standards and CRM used in this study were prepared by fusing 0.9 g of sample with 9.0 g of flux(66 % lithium tetraborate, 34 % lithium metaborate) and cast into 40 mm diameter fused beads. The measurement program used to obtain the data presented is depicted in Table 1. The analysis times can be adjusted according to the required precision.
Table 1. Measurement times (peak + background)
Precision and instrument stability
The precision, repeatability and reproducibility of the Zetium are excellent, not only for short-term measurements (Figure 1), but also for longer-term measurements carried out over a period of ten days (Figure 2). Results in Table 2 show that no significant difference can be observed in the short-term and long-term reproducibility performance of the system. For comparison, the counting statistical error (CSE) expressed in concentration units is also shown in Table 2. The CSE is theoretically the minimum possible error and the data demonstrates the inherent stability of the Zetium instrument.
Figure 1. Short-term repeatability measurements of Na2O in GBW 07105
Figure 2. Long-term repeatability measurements of Na2O in GBW 07105
The concentration values obtained in the analysis are in close agreement with the certified values for the CRM sample (Table 2).
Table 2. Short- and long-term reproducibility results for GBW 07105 (basalt)
Elemental analysis by XRF is already the key to the control of quality and production processes in the many industries analyzing wide-range oxide materials. The Zetium-WROXI-SuperQ(FP) system further extends the advantages of XRF spectrometry as the best method for oxides analysis. Analysis of certified reference sample GBW 07105 illustrates the accuracy, precision and long-term stability of the 1 kW configuration of the Zetium.
Furthermore, the long-term stability of the system is such that individual calibrations can be used for many months, reducing the need for time-consuming re-calibrations.