XXV, METHODS FOR THE ANALYSIS OF CONDIMENTS OTHEE 



THAN SPICES. 



PREPARED MUSTARD. 

 1. Preparation of Sample. 



The solid portion of the material is commonly in a finely divided condition 

 and does not require grinding, but as it tends to settle, leaving a more or less 

 clear liquid on the surface, thorough mixing is absolutely essential. This may 

 be accomplished by stirring well immediately before removing each portion for 

 analysis. 



2. Solids. 

 Dry 5 grams as directed under " VI. General Methods," on page 38. 



3. Ash. 



Burn the dry residue" obtained in the determination of moisture, as directed 

 under " VI. General Methods," on page 38. 



4. Salt. 



Determine chlorin in the ash as directed under " III. Inorganic Plant Con- 

 stituents," on page 23. 



5. Ether Extract. 



In a capsule place 10 grams of the material, about 30 grams of sand, and a 

 short stirring rod. Heat on a water bath or in a water oven. Grind until all 

 the lumps are broken up, and determine the ether extract as directed under 

 " VI. General Methods," on page 39. 



6. Protein. 



Determine the nitrogen by the Kjeldahl or Gunning method as d.rected on 

 page 5, under " I. Fertilizers." 



7. Acidity. 



Weigh 10 grams into a 200 cc graduated flask, make up to the mark with 

 water, shake, filter through a dry paper and determine the acidity in 100 cc by 

 titration with tenth-normal alkali, using phenolphthalein as indicator. State 

 the results as acetic acid. One cubic centimeter of tenth-normal alkali is 

 equivalent to 0.0060 gram of acetic acid. 



8. Copper-Reducing Matters Calculated as Starch. 



Proceed as directed under " VI. General Methods " for the determination of 

 starch by acid hydrolysis, on page 53, except that 10 grams of the material are 



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