General Application Calibration of Instrumental Measurements

The use of reference samples for method calibration and development/validation occurred hand-in-hand with the development of all modern instrumental methods of analysis. In fact, the two developments are intimately linked with one another. As already noted, G-i and W-i (Fairbaim et al. 1951 Stevens i960) illustrate first instance of reference samples specifically developed for calibration purposes. Following that, the use of BCR-i as a reference sample throughout the lunar program (Science 1970) is a prime illustration of the quality assurance and method validation applications in large-scale inter-laboratory measurement programs. 

Examples of using reference samples for calibration can be found in several chapters of the uses Methods for Geochemical Analysis (Baedecker 1987). Solid reference sample powders are used in cahbrating the dc arc emission, energy-dispersive X-ray and instrumental neutron activation analyses described, while acid-dissolved rock reference samples are used for IGP emission analyses and fused reference samples are used for wavelength-dispersive X-ray analyses. 

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