Complementary dilution method - A new version of calibration by the integrated strategy

A novel version of the integrated approach to calibration is presented as the complementary dilution method (CDM). In the series of six solutions a standard and a sample are suggested to be complementarily diluted with each other and with the blank solution, hence four linear calibration graphs may be constructed on the basis of the measurement data obtained. The analyte concentration in a sample is estimated by four values calculated in both the interpolative and extrapolative way. When comparing statistically these values with one to another, the calibration errors both the non-linear and interference effect can be detected. The flow injection system designed for realization of the CDM method is presented. The manners how the system can be adapted to examination and elimination of the calibration errors are described. The usefulness and performance of the CDM method have been confirmed experimentally on the examples of the iron determination by UV/VIS spectrophotometry and the calcium and magnesium determination by flame atomic absorption spectrometry.