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UNITED STATES DEPARTMENT OF AGRICULTURE 
fill BULLETIN No. 1114 fill 
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Washington, D. C. 
PROFESSIONAL PAPER 
August 30, 1922 
THE DETECTION OF HYPOCHLORITES AND 
CHLORAMINS IN MILK AND CREAM. 
By Thilip Ktpp. Dairy Chemist, Dairy Division, Bureau of Animal Industry, 
CONTENTS. 
Outline of experimental work. 
Preparation of reagents 
The test 
Reaction in milk 
Page. 
1 
2 
Reaction in pasteurized milk. 
Reaction in cream 
Summary 
Page. 
4 
4 
The use of hypochlorites and chloramins in the treatment of dairy 
utensils has led to much speculation as to whether or not attempts 
might be made to add these preparations to milk. This speculation 
is due to the fact that there have been no methods for detecting small 
amounts of chlorin in milk. The term " chlorin," as used in this 
paper, refers to the available chlorin derived from hypochlorites and 
chloramins. 
OUTLINE OF EXPERIMENTAL WORK. 
Very small quantities of chlorin in water solution can easily be 
detected, either by means of the iodid-starch or the <9-toluidin test. 
However, when applied to milk containing small amounts of chlorin. 
these tests are of no value, because the chlorin has combined with 
the protein of the milk and is not liberated readily at room tempera- 
ture by the addition of acids. 
It seemed desirable, therefore, to devise some methods for the 
demonstration of small amounts of hypochlorites or chloramins in 
milk and cream. The question first arose, how firmly is the chlorin 
united with the protein? If loosely combined, there was no reason 
why it should not be liberated under proper conditions. 
On experiment it was found that the chlorin could be liberated : 
and if liberated in the presence of potassium iodid, the chlorin 
would displace the iodin of the iodid. which would then combine 
3306—22 
