The particular test method selected will depend upon the accuracy required, particular test equipment available and labor allocation available. One or more of the following analytical techniques are used:
• Ion Chromotography
• Atomic Adsorption or Inductively Coupled Plasma Emission Spectroscopy
• Ion Selective Electrodes (TSE)
• Specialized Vendor Test Kits and Automated Monitors
Commercial test kits are available from numerous sources. The procedures used with these test kits are often based on the ASTM and Standard Method references (cf. Table 4) or modifications thereof.
Attention should be given to the interferences and other considerations listed for each test to be performed prior to sampling. Table 4 provides a list of these. Some general considerations are:
• Calibrate analytical equipment as outlined by the manufacturer.
• Clean and store probes as outlined by the manufacturer.
• Avoid reagent and sample contamination by keeping containers capped; and by working in a well-ventilated dust and fume free area. Avoid reagent contamination by proper handling.
• Adhere to the supplier's reagent shelf life recommendations.
• When preparing standards or reagents on-site, ensure that the reagents used are prepared and standardized as outlined in the specific test method. Adhere to the shelf life constraints in the procedure.
• Continuous sampling for on-line monitors should have the samples pre-cooled to 25°C [77°F], even if temperature compensators are used. The continuous sample flow should be sufficient to ensure the cell chamber is continuously flooded and no dissolved or entrained gases are released. Typical flow range of these prefiltered, constant temperature samples should be in the range of 40 to 500 milliliters per minute.