A Collecting Bottle Especially Adapted for the Quantitative and Qualitative Determination of Dissolved Gasses, Particularly Very Small Quantities of Oxygen

One of the sources of error in the Winkler method for the determination of dissolved oxygen in water, especially where the oxygen content is low, is the diffusion of oxygen into the water before and during the introduction of the chemicals. Another source of error is the mixing of the manganous chloride with the potassium iodide-alkali solution at the surface of the water, the chemicals adhering to the pipettes introducing these reagents having washed off at the topof the bottle, where they react with the oxygen present. In recent work involving the oxygen-free water apparatus described by Shelford in the preceding article of this volume, it was found especially desirable to eliminate the above sources of error. This was accomplished by a special bottle which allows the collecting of samples and the introduction of the chemicals without exposing the samples to air during the operation.