Apr 19 2005
PANalytical has introduced the Epsilon 5, a totally new energy-dispersive X-ray fluorescence (EDXRF) spectrometer for low-level detection of heavy elements. Epsilon 5 detects elements from sodium to uranium in solid, pressed-powder, granule, liquid, thin-film and loose material samples. Measurements can be performed in a vacuum or helium atmosphere.
In response to growing environmental concern and stricter legislation, Epsilon 5 is designed to support applications in geology, agriculture, land reclamation, fossil and secondary fuel usage, emissions monitoring, recycling, catalyst production, and electronics and electrical appliance manufacture. Environmental protection requires the analysis of diverse materials in varying concentrations, and Epsilon 5 excels at trace analysis of heavy elements such as As, Pb, Cd and the lanthanides in concentrations from 100% down to sub-ppm levels.
The Epsilon 5 features three-dimensional, polarizing optical geometry together with PANalytical’s new 600 W X-ray tube. Operating at a maximum power of 600 W with excitation voltages from 24 kV to 100 kV, the tube’s Gd anode enhances the fluorescence of elements in the rhodium to barium range. Up to 15 programmable polarizing targets can be mounted in the instrument, allowing it to be ‘tuned’ to get the lowest detection limits for a large number of elements. The basic system is configured with nine targets for comprehensive coverage of the periodic table. The additional six targets can be configured when optimum excitation conditions are required for specific applications.
A high-resolution PAN-32 liquid nitrogen-cooled, solid-state Ge detector ensures high detection efficiency across the periodic table. Unlike most solid-state detectors, it maintains 100% efficiency for heavy elements K-lines. An alternative PAN-14 detector with a Peltier-cooled Si- drift chamber can be used for less demanding applications or where liquid nitrogen is not available. The integrated X-Y sample changer has capacity for up to 130 samples in six trays, and has no restriction on the mix of sample types present on the changer. The changer automatically recognizes the difference between solid and liquid sample holders, protecting the instrument against accidental loading of liquids when the system is under vacuum.
The integrated software combines instrument control, sample handling and analysis functions in a single, ‘drag-and-drop’ program. An optional Auto-Quantify routine (based on Fundamental Parameter calibrations) handles the analysis of unknown samples. The software also incorporates a handy wizard feature that takes the user through the analysis procedure step-by-step and simplifies control of the calibration process, an important factor for laboratory accreditation requiring result traceability. Up to four password-protected user levels can be specified.
The Epsilon 5 is able to determine such low-levels of heavy elements thanks to the combination of 3D optics, a high-resolution detector and a 100 kV excitation voltage. Instead of the 2D geometry commonly used in XRF, the Epsilon 5 has a 3D (‘Cartesian’) optical geometry in which the primary beam from the X-ray tube first irradiates a polarizing target before striking the sample placed at 90°. The sample spectrum is recorded by a detector placed at 90° to the sample in a third plane, thus eliminating the effect of scattered X-ray tube radiation by polarization and considerably reducing spectral background levels.
The performance is further improved by using K-line analysis rather than L-line analysis. In XRF, heavy elements are traditionally analyzed using L-series spectral lines, which unfortunately lie in crowded parts of the spectrum and have relatively low intensities. Epsilon 5 overcomes this by combining high excitation voltages and a high-resolution solid-state detector.
Mounted on wheels and with a small footprint, the Epsilon 5 is easily maneuvered in confined laboratories. Removable panels on all sides of the instrument allow unrestricted access for maintenance. It is powered from a standard wall socket and is connected to a PC via USB and UTP ports for maximum system mobility.
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