How is chloride measured?

Chloride

Chloride, in the form of the chloride ion (Cl-), is one of the most important mineral anions in water and wastewater. The salty taste varies with the chloride concentration and is dependent on the chemical composition of the water. Some waters containing 250 mg Cl-/L may have a detectable salty taste if the cation is sodium. On the other hand, the typical salty taste may be absent in waters containing 1000 mg/L chloride if the dominant cation is calcium or magnesium.

Chloride concentration

The chloride concentration in wastewater is higher than in raw water because sodium chloride (NaCl) is a common dietary component and passes through the digestive tract unchanged. Along the coast, chloride may be present in high concentrations due to saltwater seepage into the sewage system. It may also be increased through industrial processes. High chloride content may damage pipes and metal structures as well as plant growth.

Methods for the Determination of Chloride

Six methods are presented for the determination of chloride. Since the first two methods are similar in most cases, their selection depends largely on personal preference.

The argenometric method (4500-Cl-.B) is suitable for use in relatively clear waters containing 0.15 to 10 mg of calcium per titrated portion.

The mercury nitrate method (4500-Cl-.C) has an easier endpoint to measure.

The potentiometric method (4500-Cl-D) is suitable for colored or turbid samples in which the endpoints may be difficult to distinguish. The potentiometric method can be used without a pre-correction step for samples containing ferric ions (if not present in excess of the chloride concentration), chromium, phosphate, and iron, and other heavy metals.

The ferricyanide method (4500-Cl-.E) is an automated method.

Flow injection analysis (4500-Cl-.G), an automated colorimetric method, is useful for analyzing large numbers of samples. If possible, we determine chloride by ion chromatography.

Chloride can also be determined by capillary ion electrophoresis.

Methods 4500-Cl-.C and G, which use mercury (a highly toxic substance), require special disposal measures to prevent improper discharge into wastewater.

Sampling and storage

Collect samples in chemically resistant glass or plastic bottles. The maximum volume required is 100 ml. If the sample is stored, no special preservative is required.

Water chloride measurement in Abrizan laboratory

Abrizan Industrial Research Company performs sampling and tests related to water analysis and all water parameters, such as measuring the amount of chloride in water, with high accuracy in its laboratories. Contact Abrizan Company for all tests related to water parameters.