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Definition

noun

A method used to detect the presence of pentoses with a test reagent consisting of orcinol, HCl and ferric chloride.

Supplement

This test is used to detect the presence of a pentose in urine. In the presence of pentoses, the test reagent dehydrates pentoses to form furfural. Furfural, then, reacts with orcinol. The iron ion in the test reagent will produce a bluish product. Thus, a bluish solution with which precipitate may form indicates positive for (or the presence of) pentoses.

Synonym: Bial's test, Bial's orcinol test.
See also: orcinol, pentose.