The definitive document for this technique is ISO12677: 2003, which
appeared in 2003. The essence of the technique is the conversion of the
ignited sample into a glass bead or button by fusing in a suitable lithium
borate-based flux. Once treated in this way, all particle size and mineralogical
effects that will lead to inaccuracies are destroyed. Hence, synthetic calibrations
can be set up in a similar manner using synthetic mixtures of pure oxides or
carbonates.