CombiCheck solutions are ready-to-use multi-parameter standards, Each package contains a standard solution and an addition solution. Both solutions can be used directly without dilution for quality assurance.

• The standard solution is used to check the accuracy of the results for the complete system: procedure - analytical method - reagents - photometer
• The addition solution is used to check sample-dependent influences by measuring the recovery rate and to determine the most suitable sample preparation method

The maximum number of determinations which can be made with a CombiCheck standard solution depends on the test set used. With the addition solution 280 determinations are always possible.

Parameters can be checked with their concentrations as follows:
Ammonium: 1,00 mg/L NH₄-N
Nitrogen: 5,0 mg/L N
COD: 20,0 mg/L COD