Phloroglucinol

Description

White to yellowish crystals that are used to detect the presence of mechanical wood pulp in paper. Phloroglucinol test solution contains hydrochloric acid and ethanol. A drop placed on the paper will turn red when lignin is present (detection limit is about 5%). Iron will react with phloroglucinol giving a purple product. Once the two-part solution is mixed, it has a shelf life of 2-3 months (TAPPI T401).

Synonyms and Related Terms

phloroglucinol dihydrate; 1,3,5-benzenetriol; 1,3,5-trihydroxybenzene; phloroglucine; phloroglucin stain

Chemical structure

Other Properties

Soluble in ethanol, pyridine, ether. Slightly soluble in water.

Detection limit is about 5% when used as a stain to detect mechanical wood pulp.

Composition	C6H3(OH)3
CAS	108-73-6
Melting Point	212-218
Molecular Weight	mol. wt.=126.11

Hazards and Safety

Decomposes in light; store in dark container.

Inhalation and skin contact may cause irritation.

Mallinckrodt Baker: MSDS

Additional Information

AIC Book and Paper Catalog, 10. Spot Tests, page 12.

Sources Checked for Data in Record

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 7482