36 



The methods submitted for study are as follows: 



METHODS. 



NON-VOLATILE ETHER EXTRACT. 



-Dry in a desiccator over night or until the moisture is largely removed a sufficient 

 amount of the material to yield an extract of from 0.2 to 0.25 grams. Extract according 

 to the officiaF method for the determination of crud* fat (Bui. 107, Rev., p. 39, 5 (b) 

 (1)), collecting the ether solution in a tared flask. Dry the extract at 100 C. for 

 l.Viniiiute periods until constant weight is secured. 



IODIN NUMBER. 



hetcrmine by the Hanus method (Bui. 107, Rev., pp. 136-7), using the extract 

 obtained as described in the preceding section. 



Great care should be exercised in weighing the flask, both before and after extraction,' 

 as an error of 1 milligram is equivalent to an error of over 0.5 in the iodin number. A 

 -stoppered 200 cc Erlenmeyer flask may be used for the extraction and also, with- 

 out transfer, for the determination of the iodin number, although in our experience 

 more accurate results may be secured by using a vial-mouth unstoppered flask of about 

 rapacity, thus reducing the exposed surface to a minimum. In the latter case 

 the flask, after dissolving the extract in chloroform and adding the Hanus solution, is 

 introduced into a saltmouth, glass-stoppered bottle, broken with a glass rod and the 

 titration carried out in this bottle in the usual manner. 



1 1 was suggested that in extracting the fat 3 grams of the pure paprika and 2 grams of 

 the paprika adulterated with oil be used, thus securing amounts of extract suitable 

 for determination of iodin number. 



ALCOHOL EXTRACT. 



Follow the official method (Bui. 107, Rev., p. 163). 

 DISCUSSION OF RESULTS. 



The results obtained by the five analysts who took part in the cooperative work are 

 given in the following table: 



Analysis of pure paprika and samples mixed with olirc oil. 



o Average. 



