Study on rapid detection method of ammonia nitrogen in aquatic environment

Ammonia nitrogen is an important nutrition element,which is one of important assessment indicators for water quality. A rapid detection method of ammonia nitrogen has been developed in the paper by improving the spectrophotometeric method with salicylic acid. The rapid detection method includes five solid chemical reagents,i. e. salicylic acid, sodium nitroferricyanide, sodium dichloro isocyanurate,borax and sodium carbonate with mass ratio of 0. 5: 1. 0: 0. 05: 2. 5: 25 m / m. The optimum detection time for this rapid detection method was 10 min,the optimum detection temperature is between 25℃ and 35℃,and the optimum detection p H value is between 3 and 11. 6. The standard curves are established at 25℃,and the equation of linear regression is y = 0. 8895ρ + 0. 0566 with its multiple correlation coefficient of 0. 9997. The rapid detection method is suit for the ammonia nitrogen concentration of 0. 00 ~ 1. 00 mg / L in aquatic environment with the detection limit of 0. 01 mg / L. These results are agreed with the national standard method,but its detection time is one sixth of that for national standard method. It is good for rapid in situ analysis.