ISO-12926:2012 pdf download.Aluminium fluoride for industrial use一Determination of trace elements一Wavelength dispersive X-ray fluorescence spectrometric method using pressed powder tablets.
ISO-12926 describes an X-ray fluorescence spectrometric (XRF) method for the determination of aluminium fluoride (A1F3) from the content of fluorine and the content oftrace elements in the test specimen. The method does not determine the oxygen content. The calibration reference materials are not specified in this method.
The method is applicable to industrial-grade aluminium fluoride where the concentration range for aluminium fluoride and each trace element is within the concentration range given in Table 1. The validity and precision of test results for concentrations outside these ranges has not been determined (see Note).
NOTE The determination of fluorine has an uncertainty due to mineralogical variation among origins of aluminium fluoride. Batches from different origins with the same fluorine contents can give different intensities when determined by this method and pressed tablet preparation does not eliminate this problem. An A1F3 sample of unusual mineralogical origin should be tested with an absolute method to verify that, when using this test method, the fluorine concentration range reported is valid.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
Iso 1619, Cryolite, natural and artificial — Preparation and storage of test samples
3 Principle
A representative sample of aluminium fluoride is milled. A test portion is packed and pressed on a powder tablet press to make the test tablets.
The test tablets are analysed on an X-ray fluorescence spectrometer instrument that has been calibrated using a series of aluminium fluoride reference materials covering the required concentration range of the elements to be determined.
4 Reagents and materials
4.1 Lithium tetraborate backing, analytical pure lithium tetraborate.
4.2 Acetone, analytical pure.
4.3 Aluminium tablet dish, of diameter suitable for the tablet press (5.3) and tapered to hold pressed pellets.
4.4 Mylar film, for keeping the test portion separate from press surfaces.
4.5 Binding agent, suitable for sample preparation. The following are some examples of materials that have been found satisfactory:
— polyethylene binder, PE-160, PE-190
— mill and press additive, HMPA4O – Herzog mill and press additive
— XRF Multi-Mix RXR-250, Premier Lab Supply
— Retsch – Licowax C micropowder binder (formerly known as Hoechst Wax or Hoechst LICO wax C Micropowder
— wax, Clairiant Licowax PE-190
— mixture, 9:1 of BASF styrene EMU 120 FD to Hoechst Ceridust 9615A Wax.
4.6 Cleaning agent, if required. Dupont Vertrel XF (MS-782) has been found suitable.
5 Apparatus
5.1 Wavelength dispersive X-ray fluorescence spectrometer, with vacuum path and equipped with crystals required as shown in Table 3.ISO-12926 pdf download.