| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably and accurately measure the concentration of CO2 in water. SOLUTION: In this method for water quality analysis, the pH of a sample is adjusted to 9 or above by a means installed for adding an alkaline material into the sample to change dissolved carbon dioxide (carbonic acid) to a carbonate ion or a hydrogencarbonate ion, and subsequently the ion is introduced into a concentration meter for carbon dioxide to measure its concentration. In this device, a pH adjustment part 2 which is provided with a sample tank 21 temporarily storing a collected sample, a means 24 for measuring the pH of the sample, and means 25 and 26 for adding an alkaline material into the sample according to the result of the measurement, and controls the pH of the sample within a prescribed range, is installed in the preceding stage of a concentration meter 3 for carbon dioxide. In such a constitution, dissolved carbon dioxide (carbonic acid) is changed to a carbonate ion or a hydrogencarbonate ion to be fixed in a stable state in water and to prevent the carbon dioxide in the sample from volatilizing into atmosphere, so that the concentration of the carbon dioxide can be stably kept without changing with the passage of time and can be accurately and simply measured.</p> |
