Start » Introduction » Definition of sum parameters

Sum parameters (otherwise known as composite parameters) describe similar chemical, physicochemical or biological characteristics of different substances, substance groups or mixtures of substances.

The products, substance groups and constituents, for example, might contain the same chemical element. The quantitative determination of this element allows the purity, quality, consistency etc. to be inferred.

TOC (Total Organic Carbon) or TN_b (Total Bound Nitrogen) can be cited as examples here.

A shared chemical characteristic might also be the oxidizability of constituents with a defined oxidizing agent, e.g. by dichromate, as in with the case of the sum parameter COD - Chemical Oxygen Demand.

The electrical conductivity of aqueous samples as a shared physical-chemical property can also be seen as a sum parameter.

The toxicity towards defined organisms, e.g. fish toxicity, can be mentioned as a shared biological characteristic.