AWWA B303:2005 pdf download.Sodium Chlorite
5.1.3 Aqueous sodium chlorite solution. During the unloading of the tank or tank car, five 0.5-L portions shall be taken at equally spaced intervals. The samples shall be collected in a suitable glass container. As an alternative, two larger samples may be taken, one at the beginning and one at the end of unloading. The total gross sample should be at least 2.5 L.
5.1.3.1 The gross sample, totaling 2.5 L, shall be thoroughly mixed and three 0.2-L samples retained. These samples shall be sealed in airtight, moistureproof, brown-glass containers and stored in a cool place. Each sample shall be labeled to identify it, and the label shall be signed and dated by the sampler. Distribution of the portions shall be as directed in Sec. 5.9.
5.1.4 Retention. Samples shall be retained 30 days after receipt of shipment or longer if a complaint has been made to the supplier.
5.1.5 Solid samples. The 0.25-kg sample of solid sodium chlorite delivered to the laboratory shall be mixed and reduced to approximately 100-g portions. One portion shall be thoroughly mixed but not crushed by conventional methods, such as mortar and pestle. The uniform mixture shall be stored in an airtight, moisture- proof, widemouthed, brown-glass bottle and labeled appropriately with material description and date of sample. The sample shall be kept in a cool, dry place and the container kept closed, except when portions are being weighed from it, to avoid changes in moisture content. Test solutions shall be prepared as follows:
1. Weigh approximately 40 g of sample to the nearest 0.1 mg in a weighing bottle and transfer to a 1-L flask. Dissolve in distilled water, make up to volume, and mix thoroughly. This solution is referred to as “test solution A.”
2. Pipette 50 mL of test solution A into a 500-mL volumetric flask, dilute to volume, and mix thoroughly. This solution is referred to as “test solution B.”AWWA B303 pdf download.