4IO 



Standard for Determination of Ammonia [April-July 



through a fairly wide ränge of mm., it is advantageous to have a 

 diluter Solution on band for samples very low in nitrogen content. 

 If this Solution is obtained by diluting the stronger Standard, its 

 nitrogen equivalent is not in proporton to the dilution and must 

 be obtained by comparing the same with a nesslerized Standard 

 ammonium sol. Fifteen minutes are allowed to develop the color 

 and the readings are taken within ten minutes after this time. 

 Table i gives the results of one set of readings on Standard ammon- 

 ium Sulfate, which was used to determine the time dement and the 

 amount of Nessler reagent most advantageous for the best results. 

 Additional data are given in Table 2. 



TABLE 2 



A comparison of data obtained by the micro method and the Kjeldahl 



Gunning method 



