ASTM D4927 Method for Elemental Analysis of Lubricant and Additive Components
ASTM D4927 Standard Test Methods for Elemental Analysis of Lubricant and Additive Components - Barium, Calcium, Phosphorus, Sulfur, and Zinc by Wavelength-Dispersive X-Ray Fluorescence Spectroscopy
6. Apparatus
6.1 X-Ray Spectrometer, equipped for soft X-ray detection of radiation in the range from 1 to 10 Å. For optimum sensitivity, the spectrometer is equipped with the following:
6.1.1 X-Ray Generating Tube, with chromium, rhodium, or scandium target. Other targets can also be employed.
6.1.2 Helium, purgeable optical path.
6.1.3 Interchangeable Crystals, germanium, lithium fluoride (LiF200), graphite, or polyethylene terephthalate (PET), or a combination thereof. Other crystals can also be used.
6.1.4 Pulse-Height Analyzer, or other means of energy discrimination.
6.1.5 Detector, flow proportional, or scintillation, or flow proportional and scintillation counter.
6.2 Shaker, Mechanical Stirrer, or Ultrasonic Bath, capable of handling from 30-mL to 1-L bottles.
6.3 X-Ray Disposable Plastic Cells, with suitable film window. Suitable films include Mylar, polypropylene, or polyimid with film thicknesses between 0.25 to 0.35 mil (6.3 to 8.8 µm).
NOTE 1 - Some films contain contamination of the elements of interest (Mylar in particular). The magnitude of the contamination is assessed and the same film batch used throughout the entire analysis.
7. Purity of Reagents
7.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
