Sampling for physico-chemical analyses

Samples for physico-chemical analysis will seldom present problems in drinking water sampling. Measurements of temperature, pH, electrical conductivity and oxidation reduction potential must be taken. [Pg.14]

Attention must be paid here to changes caused by access or escape of gases. For example, oxidation of dissolved bivalent iron can occur through access of oxygen. The water will become turbid and the oxidation reduction potential will be shifted. The same applies to the measurement of electrical conductivity, when precipitation of e.g. calcium carbonate, iron hydroxide or silicic acid occurs through release of gas. The sampling procedure in question must be matched to the intended measurement procedures so that secondary changes in the water before measurement can be avoided, or can if necessary be reversed or taken into account in the calculations in the laboratory. [Pg.15]

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