A brief introduction to the detection instructions of the residual chlorine and total chlorine rapid test box in water

【Introduction】Total chlorine is divided into free residual chlorine (residual chlorine) and combined residual chlorine. After chlorine is put into water, in addition to the chlorine that needs to be consumed by oxidation and reduction such as killing organic matter, reducing substances and bacteria in the water, there is still chlorine left in the water, which is called total chlorine. Free residual chlorine generally refers to chlorine molecules, hypochlorous acid molecules and hypochlorite ions in water. The combined residual chlorine content can be obtained by subtracting the free residual chlorine content from the total chlorine content. This kit is suitable for on-site rapid detection of residual chlorine and total chlorine in water. [Detection principle] The residual chlorine and total chlorine in water react with the detection reagent to form a red substance, the higher the content, the darker the color. [Testing steps] Reagent preparation of residual chlorine reagent B: unscrew the bottle cap of residual chlorine reagent B when using it for the first time, transfer the solid powder of residual chlorine reagent B1 in the centrifuge tube to the drop bottle of residual chlorine reagent B, tighten the bottle cap, and shake for 1 Minutes to dissolve the powder; Chlorine Reagent C: When using for the first time, unscrew the bottle cap of Reagent C, add 5mL of pure water or distilled water to the bottle, tighten the bottle cap, shake for 1 minute to dissolve the solid in the bottle. 2. Detection of free residual chlorine: Take 1mL water sample in a 1.5mL centrifuge tube, add 1 drop of residual chlorine reagent A, then add 1 drop of residual chlorine reagent B, cover and shake well. Observe the color of the solution within 1 to 2 minutes, and compare it with the color card to obtain the free residual chlorine content in the water sample. 3. Total chlorine detection: Continue to add 1 drop of residual chlorine reagent C to the centrifuge tube in step 2, cover and shake well. Within 2 minutes, compare it with the color comparison card to obtain the total chlorine content of the water sample. [Limit standard] 1. The limit value of free residual chlorine in drinking water factory water shall not be greater than 4 mg/L, and the residual amount shall not be lower than 0.3 mg/L. The water balance at the end of the pipe network should not be less than 0.05mg/L. 2. The limit value of total chlorine in drinking water factory water shall not be greater than 3 mg/L, and the balance shall not be lower than 0.5 mg/L. The water balance at the end of the pipe network should not be less than 0.05mg/L. 3. The standard value of free residual chlorine in artificial swimming pool water is 0.3-0.5mg/L. 【Detection limit】0.05mg/L. [Notes] 1. This method is a rapid on-site detection method, and the precise quantification should be based on the national standard method. 2. If the reading exceeds 4mg/L, the water sample can be diluted with purified water or distilled water and then measured again, and the reading is multiplied by the dilution factor to obtain the result. [Storage conditions and validity period] The reagent is stored at room temperature and protected from light, and the validity period is 6 months.