Exact matching strategies for generalised sequential standard addition calibration

A novel strategy for calibration using an exact matching form of generalised sequential standard addition is presented. The method has advantages for high throughput techniques using auto-sampling where the best repeatability for removal and delivery of solutions is obtained when a single volume setting is considered throughout. The mathematical characteristics of the procedure have been fully described and the benefits of taking large sample portions, because of the ability to then perform repeat analytical measurements, has been assessed. The method has been demonstrated using synthetic samples of mercury in dichromate of the type resulting from sampling from a stationary source. When a large number of repeated measurements were performed the precision determined was observed to be poorer than predicted theoretically; this is ascribed to drift in the analytical system over extended timescales.