2.3.3.1. Heating block

During the digestion procedure of the urinary iodine assay, it is essential that heat be distributed evenly across the heating block on every test tube. Check for even heat distribution can be achieved by placing twenty test tubes filled with 2 ml oil or sand and inserted with a thermometer each. Heating block should achieve 100�C before placing the test tubes and heated for 20 minutes. Temperature of each thermometer should be recorded and mean � SD is calculated. The temperatures recorded across the digestion unit should fall within the manufacturer's stated temperature distribution range. CV should be �5%.
