抄録
A direct simultaneous determination of sulfur, calcium, barium and zinc in lubricating oils and additives by X-ray fluorescence method was studied and the following conclusions were obtained.
(1) By the X-ray fluorescent analysis, sulfur was directly determined using a calibration curve, calcium and barium determined by correcting the sulfur absorption effect, while zinc was determined from calibration curve which was drawn from standard samples containing four elements. The range of determination of each element is as follows. S: 0∼2.6wt%, Ca: 0∼1.0wt%, Ba: 0∼0.68wt%, Zn: 0∼0.08wt%.
(2) Accuracy of this analytical method is shown below as the Standard Deviation (%) S: 3∼6% Ca, Ba, and Zn: about 2%.
(3) Commercial lubricating oils and additives were analysed for each of the foregoing elements by using the two methods-conventional chemical analysis and X-ray fluorescence method, and the results obtained therefrom were identical.
No problems have been encountered in applying this X-ray fluorescence method to industrial analyses, and therefore this method can be used for practical purposes instead of chemical analysis.
(4) It took only 40 minutes to complete the analysis of a single sample for three or four elements, thereby assuring rapidness and automation of this method.
