BoranicAL MuSEUM LEAFLETS VoL. 25, No. 7 
CHEMICAL TEST FOR 
IDENTIFICATION OF COPROLITES 
ELIZABETH A. COUGHLIN 
Archaeological identification of coprolites has, for the most 
part, been based on visual and microscopic evaluations of 
gross morphology and of dietary botanical inclusions. These, 
combined with the absence of any major skeletal network, but 
possibly with inclusions of small dietary skeletal remains, have 
served as indicators of coprolites. 
Chemical analysis, however, of the suspected coprolite itself 
and of nearby associated material from the same stratum, level 
or feature offers further substantiation for identification. 
Significantly high levels of nitrates (which are the final and 
most highly oxidized form of nitrogen in the nitrogen cycle of 
biologic oxidation of organic nitrogen compounds) indicate the 
final stages of biological degradation and are thus suitable for 
indentification of coprolites. 
A colorimetric estimation of nitrates (NO3) can be made by 
measuring the yellow color produced by the reaction of nitrates 
with brucine at a wave-length of 410 millimicrons. 
PROCEDURE 
1. PREPARATION OF STANDARDS 
A. Stock Nitrate Solution: dissolve 721.8 mg. anhydrous 
potassium nitrate, KNO3, and dilute to 1,000 ml. with 
distilled water. (This solution contains 100 mg /1 N.) 
B. Standard Nitrate Solution: dilute 10.00 ml. Stock Ni- 
trate Solution to 1,000 ml. with distilled water. Prepare 
immediately before using. 
C. Nitrate Standards: prepare standards in the range of 0.1 
— 1mg/IN. by diluting 1.00, 2.00, 4.00, 7.00, and 10.00 
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