The Preparation of Twenty Ore Standards, IGS 2O‐39. Preliminary Work and Assessment Of Analytical Data

Abstract

The first inter‐laboratory investigation of accuracy in are analysis was carried out by the Institute of Geological Sciences in 1968. The preparation of the 19 samples involved in this study is briefly described and the results are summarised. The second survey on twenty samples was initiated in 1972 and completed in 1976. The samples prepared are: IGS 20, nickel concentrate; IGS 21, nickel ore (norite); IGS 22, nickel ore (serpentinite); IGS 23, nickel ore (laterite); IGS 24, cobalt ore; IGS 25, wolframite; IGS 26, tin‐tungsten ore; IGS 27, molybdenum‐tungsten ore; IGS 28, lead‐zinc concentrate; IGS 29, pyrolusite; IGS 30, chromite; IGS 31, ilmenite; IGS 32, rutile; IGS 33, columbite; IGS 34, tantalite; IGS 35, zircon; IGS 36, monazite; IGS 37, uraninite; IGS 38, baryte; IGS 39, fluorite. After proper grinding and homogenisation, aliquots of the samples were issued to over 50 laboratories in 14 countries for analysis. Methods used and problems encountered in dealing with the 5000 results are described. It is seen that neither purely statistical methods nor an empirical approach are entirely satisfactory in the interpretation of data that vary widely in both in quality and quantity. An important outcome of the work is that 55 elemental concentrations within the 20 samples have been given recommended values and confidence limits for use as standards. Moisture values, analytical results and participating laboratories are listed in three appendices.

Method validation and uncertainty for the determination of rare earth elements, yttrium, thorium and phosphorus in monazite samples by ICP-OES

“…IGS-36 is the only monazite CRM for which certified values are available for most constituent elements and hence it has been widely analyzed. In this study, CRM"IGS-36" was analyzed by the test method in ten replicates and values obtained were www.bosaljournals/chemint/ editorci@bosaljournals.com checked against the accepted values (Lister, 1978;Lister, 1981). The results presented in Table 5 are within acceptable uncertainty limits of the certified/accepted values for the CRM, thereby confirming the accuracy of the method.…”

A Preliminary Study on the Preparation of Four Pacific Ocean Polymetallic Nodule and Sediment Reference Materials: GSPN‐2, GSPN‐3, GSMS‐2 and GSMS‐3

“…(4) Individual data for severe outliers were checked using the S-shaped data distribution graph (Lister 1978, Luo 1995. Any significant deviations from inter-method and inter-laboratory averages were also checked by evaluating the distribution patterns of data plotted on the appropriate data spectrum graph ( Figure 2).…”