General description

This MQuant^® Total Hardness test (formally MColortest^®) is suitable for the titrimetric determination using a convenient dropping bottle. MethodCalcium and magnesium ions react with an indicator to form a red complex compound. The indicator is released from this compound by titration with a solution of ethylenedinitrilotetraacetic acid disodium salt dihydrate (Titriplex^® III). At the titration end-point the color changes to green. The total hardness is determined from the consumption of titration solution.

The test measures the content of salts of the alkaline earth metals calcium, magnesium, strontium and barium in freshwater. For the determination the titrant is added dropwise to the sample until the added indicator changes its color.

Method: titrimetric with dropping bottle MColortest^®

Legal Information

MQUANT is a registered trademark of Merck KGaA, Darmstadt, Germany

Titriplex is a registered trademark of Merck KGaA, Darmstadt, Germany

MCOLORTEST is a registered trademark of Merck KGaA, Darmstadt, Germany