1/6 



Sanitary Stiidies of Baking Powders 



First method : lo cc. of the FeClg sol. required 17.70 cc. of the KMn04 



ii (i i( II (i ii i( (< jt- ^^ ii 



Second " " " " " " " 17.75" 



i< (< <( (< (( <( ii <( jf- »-. ii 



Average ^7-72 



Therefore, i cc. of the FeCla sol. is equivalent to 3.42 mg. of FeaOg. 



4. ESTIMATION OF THE IRON IN THE STANDARD FeCLs SOL. IN 

 THE PRESENCE OF SODIUM ALUM. IQ CC. of thc FcCls SOl. WCrC 



mixed with 10 cc. of the 2 per cent. sol. of sodium alum; then the 

 mixture was analyzed according to Jones and Jeffrey's (10) modi- 

 fication of the Zimmerman-Rheinhardt method, with the following 

 results : 



(a) 17.70 cc. of KMn04 sol. were required. 



(b) 17.75 " " 



These results show that the method is absolutely accurate in the 

 presence of aluminum, 



5. ESTIMATION OF IRON IN THE STANDARD FEÜLg SOL. BY THE 



UNMODiFiED A.O.A.C. METHOD. The only advantage of the modi- 

 fied method (Steel's) over the original A.O.A.C. method Hes in 

 the greater facility in estimating the iron. That equally accurate 

 results can be obtained by both methods can be seen by a glance at 

 Table i. 



TABLE I* 



Data pertaining to the estiniation of iron by the A.O.A.C. method and Steel's 



method 



* 10 cc. of the Standard ferric chlorid sol. plus 5 cc. of the Standard alum 

 sol. were used in each of these experiments. 



6. ESTIMATION OF ALUMINUM BY THE MODIFIED A.O.A.C. 



METHOD (Steel's). The estimation of aluminum by this method 



