Determination method for dissolved oxygen in water

Abstract

The invention relates to a determination method for dissolved oxygen in water, and belongs to the technical field of sensors in analytical chemistry field. According to the present invention, a mixing liquid prepared from cellulose acetate and an octaethyl platinum porphyrin solution is coated on a glass slide in a dropwise or rotating manner, and drying is performed to prepare an oxygen sensitive film; the detection apparatus for dissolved oxygen in water comprises a nitrogen saturation sample, an oxygen saturation sample, peristaltic pumps, a cuvette, a fluorescence spectrophotometer and recorder; and two cups having a lid are respectively filled with the nitrogen saturation sample to be determined and the oxygen saturation sample to be determined, the contents of the nitrogen saturation sample and the oxygen saturation sample are adjusted by adjusting the flow rates of the two peristaltic pumps, the samples to be determined are mixed through a three-way valve to form sample liquids having different dissolved oxygen concentrations, the sample liquid finally enters the cuvette containing the oxygen sensitive film, the fluorescence intensity at an excitation wavelength of 535 nm is determined through the fluorescence spectrophotometer, a Stern-Volmer curve is drawn, and the dissolved oxygen content in water is measured.

Description

technical field [0001] The invention discloses a method for measuring dissolved oxygen in water, which belongs to the technical field of sensors in the field of analytical chemistry. Background technique [0002] Oxygen exists in a wide range of forms in nature, among which it exists in the water medium in the form of molecules, which is called dissolved oxygen in water. The dissolved oxygen content in water and its measurement are closely related to people's production and life, and are one of the most important testing items in many departments. Fast, reliable and accurate dissolved oxygen detection is of great significance in the fields of water quality monitoring, fishery production, industrial manufacturing, and marine resource development. [0003] There are many methods for the determination of dissolved oxygen, mainly including iodometric method, electrochemical method, spectrophotometric method and fluorescence analysis method. Among them, although the iodometric ...

AI Technical Summary

Problems solved by technology

Among them, although the iodometric method is more accurate in measurement, the procedure is too cumbersome, the consumption time is too long, and it cannot be analyzed online.

Although the electrochemical method realizes online detection, the oxygen in the sample will be continuously consumed during the measurement process, and the sample must be stirred continuously

The spectrophotometric method is to measure the dissolved oxygen concentration according to the change of absorbance after the oxidation reaction between the reduced state indicator and the oxygen molecule. This method is easy to operate, but the accuracy needs to be improved.

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