Novel approach to calibration by the complementary dilution method with the use of a monosegmented sequential injection system

Novel approach to calibration by the complementary dilution method (CDM) is presented. The CDM integrates in a single procedure the set of standards and the standard addition calibration methods. The approach is implemented with the use of the fully automated monosegmented sequential injection system coupled to FAAS as a detector. It relies on generation of a series of standard solutions consistent with the CDM calibration method in subsequent monosegments using a single stock standard solution, sample and diluent in appropriate proportions. Two versions of the method, basic and extended have been verified. They have been tested on the example of magnesium determination in a synthetic sample with errors of repeatability (R.S.D.) and accuracy (R.E.) less than 3.2%. Subsequently, they have been applied to magnesium and calcium determinations in water. The results obtained are comparable with the appropriate certified values as well as with the results received by traditional calibration methods performed separately in batch system. Using the system, a complete sample analysis takes 8 or 21 min with sample or standard consumption less than 1 or 2 mL in basic and extended versions, respectively.