There are many ways to test for chlorides. A chloride test strip is the simplest. A chloride test kit is more accurate. A chloride ion selective electrode with a multi-parameter meter is the most accurate. The method chosen depends upon whether the test is to be performed in the field or in the laboratory; how many tests will be performed per day; and how accurate the test must be. The method chosen also will depend on the laboratory skill of the user.
For the field a test strip is the easiest; precision can be up to 20 mg/L for the Hach Chloride test strips. Test strips are dipped into the sample and the results read from the strip.
If an EPA approved test method is needed in the field the Chemetrics Chloride test kit with a precision of 2mg/L is appropriate. Test kits are supplied with reagents, and sample vessels. With each testing group blanks and standards must be prepared.
The Chloride ion selective electrode will give the most accuracy in the lab. The lab must have an ISE meter such as the Thermo Orion 4 Star meter. With carefully prepared standard curves very good accuracy can be achieved with the Thermo Scientific combination Chloride ISE.