How Do You Measure Nitrates And Nitrites In Water?


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Sadia Batool answered
Take 50 ml of sample water in china dish and placed it in oven at 1000C for 5 hours. Then test nitrates in the dried china dishes. Add 1 ml of disulphonic acid and 1ml NaOH to china dish. If it will give light green color then it will contain nitrate in it. Prepare standard solution for spectrophotometer. Standard solution is consisting of 1ml disulphonic acid, 6N NaOH and 50ml distilled water. We check the nitrate containing samples in spectrophotometer for nitrate percentage detection. Spectrophotometer is on and then it is on with visible light. Then the standard solution, sample solution and distilled water put in it. Then add distilled waster to it
Nitrate is measured with spectrophotometer Hitachi UV-Vis, 1100, Japan. The following reagents are required.
1- Phenoldisulphonic acid conc.
2- Potassium Hydroxide (6N). Dissolve 16.8g of KOH in 100 ml distilled water.
3- Standard Nitrate solution (100ppm). Dissolve 137mg of NaNO3 in 1000ml of distilled water.
50ml of sample in china dish is evaporated to dryness at 105 °C. added 1ml phenol disulphonic acid. Equilibrate for few minute. Add 1ml of KOH and diluted up to 50ml. Measure the yellow color at 410 nm

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