Method for detecting low-concentration ammonia nitrogen in drinking water

[0027] Example 1: The detection of low-concentration ammonia nitrogen in drinking water is completed according to the following steps

[0028] 1 Take an appropriate amount of environmental water sample, add zinc sulfate (100g / L) for flocculation and sedimentation for 10 minutes, and transfer 50 mL of supernatant to the colorimetric tube

[0029] 2 Add 4 mL of sodium hydroxide solution (6M) in water and mix well

[0030] 3 Add 1mL potassium sodium tartrate solution to the water, mix well, the concentration of potassium sodium tartrate solution is 500g / L

[0031] 4 Add 1.5mL Nessler's reagent (HgCl 2 -KI-KOH)

[0032] 5 Let stand for 30 minutes

[0033] 6 Take the blank test as a reference, and measure the absorbance of the sample at a wavelength of 420nm

[0034] 7 Take ammonium chloride (concentration 0~2.0mg / L) as the standard solution, measure the absorbance value according to the steps 1-6, and draw the standard curve

[0035] 8 According to the formula Calculate the ammonia nitroge

[0036] Example 2: The detection of low-concentration ammonia nitrogen in drinking water is completed according to the following steps

[0037] 1 Take 25mL sample to colorimetric tube

[0038] 2 Add 1 mL of sodium hydroxide solution (8M) in water and mix well

[0039] 3 Add 0.5mL potassium sodium tartrate solution to the water, mix well, the concentration of potassium sodium tartrate solution is 500g / L

[0040] 4 Add 0.5mL Nessler's reagent (HgI 2 -KI-KOH)

[0041] 5 Let stand for 10 minutes

[0042] 6 Take the blank test as a reference, and measure the absorbance of the sample at a wavelength of 420nm

[0043] 7 Take ammonium chloride (concentration 0~2.0mg / L) as the standard solution, measure the absorbance value according to the steps 1-6, and draw the standard curve

[0044] 8 According to the formula Calculate the ammonia nitrogen concentration in the water sample, where C is the ammonia nitrogen concentration in the water sample, A is the absorbance value of the sample, a is the int

[0050] Example 3: The detection of low-concentration ammonia nitrogen in drinking water is done according to the following steps: 1 Take 25mL tap water sample to colorimetric tube

[0051] 2 Add 1 mL of sodium hydroxide solution (8M) in water and mix well

[0052] 3 Add 0.5mL potassium sodium tartrate solution to the water, mix well, the concentration of potassium sodium tartrate solution is 500g / L

[0053] 4 Add 0.5mL Nessler's reagent (HgI 2 -KI-KOH)

[0054] 5 Let stand for 20 minutes

[0055] 6 Take the blank test as a reference, and measure the absorbance of the sample at a wavelength of 420nm

[0056] 7 Take ammonium chloride (concentration 0~2.0mg / L) as the standard solution, measure the absorbance value according to the steps 1-6, and draw the standard curve

[0057] 8 According to the formula Calculate the ammonia nitrogen concentration in the water sample, where C is the ammonia nitrogen concentration in the water sample, A is the absorbance value of the sample, a is the inter