Method and procedure for rapid detection of residual chlorine in water

Chlorine-containing preparations are the earliest and most widely used disinfectants for drinking water, which are of great significance to the implementation of disinfection and to ensure the disinfection effect. The determination of available chlorine in drinking water chlorine is a method to characterize the oxidation capacity of chlorine-containing disinfectants based on chlorine gas. The higher the effective chlorine content in the disinfectant, the stronger the disinfection ability and the more thorough the killing of microorganisms. Residual chlorine refers to the residual chlorine content in water after the disinfectant has been used for a certain period of time. After the water is chlorinated and disinfected, if enough residual chlorine can be maintained, it means that not only the disinfection effect is reliable, but also the disinfection effect is continuous. Rapid detection method for residual chlorine in water: This rapid detection box uses the principle of visual colorimetry for semi-quantitative detection. The color determines the content of available chlorine and residual chlorine in the sample. Attached are the 'Hygienic Specifications for Catering Industry and Collective Catering Distribution Units' (Wei Jianfa [2005] No. 260), and the attached 'Technical Specifications for Hygienic Quality of Bleach Powder and Bleach Powder Disinfectants (Trial)', the concentration and use of disinfectants are as follows: GB/ T 5750.11-2006 stipulates that the concentration of residual chlorine in factory water should be [0.3, 4]mg/L, the drinking water at the end of the pipe network should be ≥0.05mg/L, and the swimming pool water should be in [0.2, 1.0]mg/L , the disinfection water for swimming pool feet should be [5, 10]mg/L. Test steps of test paper for rapid detection of residual chlorine in water: 1. Determination of available chlorine in disinfectant: take 1ml of poisonous sample, add 4ml of water, shake well, immerse all the test paper in the test solution and take it out immediately, wipe off the excess liquid on the edge of the test paper, Lay the test paper face up, compare it with the color card after 40 seconds, and read the result. When the color of the test paper is too dark and exceeds the range of the color chart, the sample can be diluted for measurement; 2. Determination of residual chlorine in water: take an appropriate amount of sample in a clean and dry container, immerse all the test paper pieces in the sample solution and take it out immediately. Wipe off excess liquid from the edge of the test paper, place the test paper block face up horizontally, compare it with the color chart after 40 seconds, and read the result. Judgment of results: 1. The concentration of available chlorine in the diluted sample is equal to the reading of the color comparison card multiplied by the dilution factor, and the concentration of residual chlorine in the water is equal to the reading of the color comparison card; 2. Compared with the above standards, the concentration of available chlorine is greater than or equal to the corresponding disinfection object The required value is qualified, and the value less than the required value is unqualified; the domestic drinking water meets the requirements of GB/T5750.11-2006 as qualified, and the non-conformity is unqualified. Quick detection test paper for residual chlorine in water: 1. This test paper is easily affected by moisture, light and heat. 2. Do not touch the reaction area of ​​the test paper with your hands, and do not take out the desiccant. The removed test strips should be used immediately, and each test strip can only be used once. 3. This test paper is not suitable for the detection of chlorine dioxide available chlorine. Rapid detection of residual chlorine in water: The test paper should be stored in a dry environment at room temperature, away from light, and should not be placed in the refrigerator. Valid for 12 months. Test paper for rapid detection of residual chlorine in water: standard configuration sheet for determination of residual chlorine in water, test paper, desiccant, certificate of conformity, sample tube, straw.