ASTM International

Standard Test Method for Determination of Calcium, Chlorine, Copper, Magnesium, Phosphorus, Sulfur, and Zinc in Unused Lubricating Oils and Additives by Wavelength Dispersive X-ray Fluorescence Spectrometry (Mathematical Correction Procedure)
 N D6443

Annotation

This test method covers the determination of calcium, chlorine, copper, magnesium, phosphorus, sulfur, and zinc in unused lubricating oils, additives, and additive packages by wavelength dispersive X-ray fluorescence spectrometry. Matrix effects are handled with mathematical corrections.

For each element, the upper limit of the concentration range covered by this test method is defined by the highest concentration listed in Table 1. Samples containing higher concentrations can be analyzed following dilution.

For each element, the lower limit of the concentration range covered by this test method can be estimated by the limit of detection (LOD)2 (see also 40 CFR 136 Appendix B) or limit of quantification (LOQ),2 both of which can be estimated from Sr, the repeatability standard deviation. LOD and LOQ values, determined from results obtained in the interlaboratory study on precision, are listed in Table 2.

LOD and LOQ are not intrinsic constants of this test method. LOD and LOQ depend upon the precision attainable by a laboratory when using this test method.

This test method uses regression software to determine calibration parameters, which can include influence coefficients (that is, interelement effect coefficients) (Guide E1361), herein referenced as alphas. Alphas can also be determined from theory using relevant software.

Setup of this test method is intended for persons trained in the practice of X-ray spectrometry. Following setup, this test method can be used routinely.