Demonstration of a standard dilution technique for standard addition calibration.
A standard dilution approach to sequential (S-SAC) and conventional (C-SAC) standard addition calibration is introduced and described theoretically. The two calibration methods have then been demonstrated experimentally for chloride measurement in seawater samples. S-SAC showed superior results for such a sample as a function of the steeper extrapolation resulting from the calibration process. The conflicting effects on S-SAC of extrapolation precision and sensitivity to intercept correction have been discussed and recommendations concerning the optimum ratio of target analyte concentration in the calibration standard to that in the unknown sample for the use of this technique have been made.
Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK. Electronic address: richard.brown@npl.co.uk.
Richard J C
RJ
Brown
Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK.
Chantal L
CL
Mustoe
Calibration; Dilution; Extrapolation; Precision; Standard addition