In preparing measurement programmes,NCESS XRFs use reliable calibration standards which are representative of the matrix and target element concentration ranges to be analyzed. Measuring arrangement follows empirical method based on the analysis of standards with known elemental compositions. Sample preparation method is same for a given measurement method. When standards are few (for eg. Zircon, Ilmenite, rutile, clays etc.) alternative “standardless” techniques is adopted using typical composition of the sample. The standardless calibration model is verified and optimized against single standard sample. We are using over 65 certified reference standards to obtain good results for trace elements in all types of geological samples.
Following is the list of International reference standards used in our lab.
Basic rock Composition
BCR2*, BIR1*, DNC1*, BE-N, W2a*, AGV2*, BHVO2*, ANG#, BR*, DR-N#, PM-S#, WS-E#, JA-1A+, JA-2+, JA-3+, JB-1B+, JB-2+, JB-3+, JGB-1, JGB-2
Granitic rock composition
G2*, GSP2*, STM1*, SARM1@, SARM2@, SY3@, RGM*, GA#, GH#, GS-N#, AC-E#, MDOG#, ISHG#, VS-N#, JG-1+, JG-2+, JG-3+, JR-3+, JSY-1+
Sediments and Soils
SCO1*, SDC1*, SO1@, MAG1*, SGR1*, BX-N#, MESS3, PACS2, HISS1, JD-1+, JLK-1+, JSD-1+, JSD-2+, JSD3+, JMS-1+, JMS-2+, VL1′, VL2′, SLB’, JSO-1+
Mineral Analysis
Minerals (ilmenite, rutile, zircon etc) are analysed by standardless method, which is verified and tested against certified mineral standards like SARM 59 (Ilmenite), SARM 61(rutile) and SARM 62 (zircon)
Standard samples Source: *USGS, USA; #: CNRS, France; @NRCAN, Canada; +Venezuela