User manual HANNA INSTRUMENTS HI 3810

[. . . ] Instruction Manual SIGNIFICANCE AND USE The concentration of dissolved oxygen in water is extremely important in nature as well in man's environment. In the oceans, lakes, rivers, and other surface water bodies, dissolved oxygen is essential to the growth and development of aquatic life. Without oxygen, the water can become toxic due to the anaerobic decaying of organic matter. [. . . ] Note: Any damaged or defective item must be returned in its original packing materials. PRINTED IN ITALY CHEMICAL REACTION A modified Winkler method is used. Manganous ions react with oxygen in the presence of potassium hydroxide to form a manganese oxide precipitate (Step 1). An azide is present to prevent any nitrite ions from interfering with the test. On addition of acid, manganese oxide hydroxide oxidizes the iodide to iodine (Step 2). Since the amount of iodine generated is equivalent to the oxygen in the sample, the concentration of iodine is calculated by titration of thiosulfate ions that reduce the iodine back to iodide ions. ­ Step 1: 2Mn2+ + O2 + 4OH 2MnO(OH)2 ­ Step 2: MnO(OH)2 + 2I + 4H+Mn2+ + I2 + 3H2O 2­ 2­ ­ Step 3: I2 + 2S2O3 2I + S4O6 INSTRUCTIONS READ ALL THE INSTRUCTIONS BEFORE USING THE TEST KIT LOOK AT THE BACK PAGE FOR THE ILLUSTRATED PROCEDURE · Rinse the glass bottle 3 times with water sample and fill to overflow. Insert stopper and ensure that a small part of the sample spills over. SPECIFICATIONS Range 0 to 10 mg/L (ppm) O2 Smallest Increment 0. 1 mg/L (ppm) O2 Analysis Method Azide Modification Titration Sample Size 5 mL Number of Tests 110 (average) Case Dimensions 260x120x60 mm (10. 2x4. 7x2. 4") Shipping Weight 910 g (34. 0 oz. ) · Add some more sample to fill the bottle completely. Carefully stopper the bottle again and ensure that a part of the sample spills over. This is to make sure that no air bubbles have been trapped inside, which would corrupt the reading. The sample becomes orange-yellow and a flocculent precipitate will form if oxygen is present. · Let the sample stand and the flocculent precipitate will start to settle. · After approximately 2 minutes, when the upper half of the bottle becomes limpid, add 10 drops of Sulphuric Acid Solution. · Again stopper the bottle and invert it until all particulate material is dissolved. The sample is ready for measurement when it is yellow and completely limpid. Rinse the plastic vessel with the solution in the bottle, fill to the 5 mL mark and replace the cap. · Add 1 drop of Starch Indicator through the cap port and mix by carefully swirling the vessel in tight circles. [. . . ] Official Methods of Analysis, A. O. A. C. , 14th Edition, 1984, pages 620-621. Standard Methods for the Examination of Water and Wastewater, 16th Edition, 1985. 03/02 HEALTH & SAFETY DATA The chemicals contained in this test kit may be hazardous if improperly handled. Read Health and Safety Data Sheets before performing the test. ISTR3810R2 HI 3810 DISSOLVED OXYGEN TEST KIT 1 Rinse x 3 2 3 4 5 mL sample 5 6 7 8 [. . . ]