Section 6: Chemical Analysis

The American Society for Testing and Materials (ASTM) method D4327-84 for analyzing chloride anions in water by ion chromatography is recommended (2). This method requires only a few millilitres of the liquid impinger sample and readily distinguishes between fluoride, bromide and chloride ions. The approximate detection limit of the method is 0.1 μg/mL in the water solution. For high concentration samples, the range can be greatly extended by appropriate dilution.

An alternate procedure is the ASTM Method D512-81 for "Chloride Ion in Water-Method A - Mercurimetric Titration" (3). The approximate detection limit for this method is 1 μg/mL in the water solution. Again the range can be extended by appropriate dilution. Bromide, iodide, cyanide and thiocyanate anions will be titrated by mercuric nitrate and measured as chloride. In water, sulphite and sulphur dioxide interfere and must be removed by oxidation.