EXAMINATION OF FROZEN EGG PRODUCTS. 



83 



Table 36. 



-Ammonia nitrogen obtained by use of Duboscq and Schreiner colorimeters in 

 the nesslerization method. 



Sam- 

 ple 

 No. 



Initial of 

 analyst. 



Ammonia nitrogen. 



Sam- 

 ple 

 No. 



Initial of 

 analyst. 



Ammonia nitrogen. 



Duboscq. 



Schreiner. 



Titration. 



Duboscq. 



Schreiner. 



Titration. 



45 



fB 



Mg. per 

 100 grams. 

 1.5 

 1.6 

 1.9 

 2.1 

 4.6 

 3.1 

 2.3 

 2.6 

 2.9 

 2.4 

 3.0 

 6.3 

 6.1 

 6.5 

 9.9 

 7.0 

 7.8 

 2.3 

 2.1 

 2.0 

 2.1 

 2.1 

 2.3 

 2.4 

 2.3 

 2.4 

 2.4 

 1.9 

 2.8 

 2.7 



Mg. per 

 100 grams. 

 1.2 

 1.3 

 1.5 

 1.8 

 3.9 

 2.7 

 2.2 

 1.8 

 2.4 

 2.5 

 2.4 

 6.0 

 6.7 

 5.9 

 8.2 

 8.0 

 8.2 

 2.1 

 2.2 

 1.4 

 2.0 

 2.0 

 1.5 

 2.4 

 2.1 

 2.0 

 2.3 

 1.6 

 2.3 

 2.7 



Mg. per 

 100 grams. 

 2.0 

 1.9 

 2.2 

 2.8 

 4.5 

 3.0 

 2.6 

 3.0 

 2.8 

 2.6 

 3.0 

 6.9 

 6.5 

 6.8 

 7.6 

 8.0 

 8.7 

 2.6 

 2.4 

 2.7 

 2.8 

 2.9 

 2.3 

 2.2 

 2.3 

 2.8 

 2.3 

 2.8 

 2.6 

 3.0 



66 

 67 



76 



77 



68 



69 



70 



71 



72 



73 



f H 



Mg. per 

 100 grams. 

 1.8 

 3.0 

 2.0 

 2.3 

 2.4 

 2.3 

 2.7 

 2.7 

 7.0 

 8.0 

 8.2 

 6.5 

 3.7 

 5.5 

 6.5 

 4.5 

 5.7 

 2.2 

 2.4 

 2.9 

 2.5 

 2.4 

 2.4 

 2.7 

 4.5 

 2.7 

 3.3 

 2.0 

 3.0 



Mg. per 

 100 grams. 

 1.4 

 2.8 

 2.0 

 2.5 

 2.2 

 2.3 

 2.1 

 2.3 

 6.8 

 6.6 

 8.5 

 6.1 

 2.8 

 5.3 

 6.7 

 4.5 

 4.9 

 2.1 

 1.5 

 2.4 

 2.4 

 1.8 

 2.1 

 2.7 

 3.1 

 2.3 

 3.2 

 1.4 

 3.6 



Mg. per 

 100 grams. 

 2.9 



46 



B 



{s 



3.1 



47 



\b 



IE 



2.1 



48 



B 



Jh 



2.5 



51 



|B 



Is 



2.2 





ID 



IE 



2.4 



60 



Je 



Jh 



2.9 





1h 



Is 



2.8 





Je 



IE 



7.5 



61 



H 



6.6 





Ih .... 



Is 



8.1 





ID... 



(E 



4.2 



62 



Je 



Ih 



4.9 





Ih 



Is 



4.5 





ID 



IE 



4.4 



63 



Je 



H 



5.0 





Ih 



Is 



4.7 





ID 



IE 



2. 1 



74 



E 



H 



2.1 





Ih 



is 



2.4 





ID 



IE 



2.1 



75 



Je. 



Jh 



2.5 





Ih 



Is 



2.4 





IE 



IE 



2.5 



64 



Jh 



Jh 



2.8 





Is 



Is 



2.8 





IE 



IE 



2.7 



65 



Jh 



Jh 



3.2 





Is 



js 



3.1 



66 



E 







From Table 36 it is evident that the Schreiner instrument may 

 not be substituted for the Duboscq colorimeter, since it gives results 

 which are in the majority of cases decidedly lower than those 

 obtained with the Duboscq instrument.. By comparing the nessler- 

 ization results with the titration results, it will be seen that the 

 results with the Duboscq colorimeter are too low and that the results 

 with the Schreiner, which are still lower, are decidedly inaccurate. 



Nesslerization Method for Ammonia Nitrogen. 



Dissatisfaction with the nesslerization method for the determination 

 of ammonia nitrogen was expressed by the chemists throughout the 

 cooperative work, not only because of the lack of uniformity of results, 

 but also because of mechanical chfhculties in the method. Much 

 trouble was experienced with foaming. At first this was overcome 

 to a large extent by adding a few cubic centimeters of amy! alcohol, 

 but this method has the disadvantage that the amyl alcohol, due to 

 its volatility, often must be added more than once during the aera- 

 tion, and also it has a tendency to give a slight blank reading. 

 Later very heavy cylinder oil was used successfully to prevent foam- 

 ing. Recently one of the analysts reported in connection with 

 some determinations made on samples subsequent to the coopera- 



