Ashing temperature and time

Ashing may be carried out at temperatures up to 1100°C which enables removal of part of the matrix. The matrix that remains can still be a problem. In the author s experience (Halls and Fell, 1981), the effect of the matrix on the signal can be minimized by control of the ashing temperature and time. In this way, simple aqueous standards can be used for calibration. However, the experience of others, particularly in the determination of manganese in serum, was that aqueous calibration could not be used and they used either matrix-matched calibration with a serum low in manganese (Pleban and Pearson, 1979 Subramanian and Meranger, 1985 N6ve and Leclerq, 1991) or standard additions on each sample (Casey et al., 1987). Smeyers-Verbeke et al. (1976) have studied the... 

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