The OSHA sampling and analytical method for chlorine is discussed in reference 9.1. The principle of sampling is described in reference 9.2. The analytical procedure is based on an iodometric technique which uses a residual chlorine electrode (RCE) for detection (9.3.). The validation of the chlorine method consisted of the following experimental studies: Analysis of a total of eighteen samples (six samples at each of the three test levels) which were prepared by adding known amounts of standardized chlorine solution to 0.1% sulfamic acid collecting solution. Analysis of a set of eighteen samples (six samples at each of the three test levels) collected from dynamically generated test atmospheres at approximately 0.5, 1, and 2 times the OSHA Permissible Exposure Limit (PEL) of 1 ppm. Determination of the collection efficiency of the 0.1% sulfamic acid sampling solution. Determination of potential breakthrough when sampling. Determination of the storage stability over 30 days for collected samples. Comparison with an independent method. Assessment of the method. The details with respect to each of these items are discussed in the following sections. All experiments were based on the ability of the method to collect and analyze a 15-L air sample for each concentration tested. The sample preparation and analytical technique used during the method evaluation follow that described in reference 9.4. A revised method (9.1.) is also available. --------------------------------------------------------------------------------Note: The revised version of the method (9.1.) differs in one major point from reference 9.4.: Preparation of samples and standards for analysis. It is now recommended to prepare samples and standards in 0.1% sulfamic acid solutions rather than the deionized water previously used (9.5.). --------------------------------------------------------------------------------1. Generation A dynamic standard generator (Model 350, Analy...
