University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Process liquor

Classification: Industrial -> tanning -> process liquor

Citations 1

"Spectrophotometric Determination Of Tannin In Tanning Effluent With A Flow Injection System"
Analyst 1995 Volume 120, Issue 4 Pages 1185-1188
Valderi L. Dressler, Enio L. Machado and Ayrton F. Martins

Abstract: A 50 mL portion of tanning effluent was acidified with 5% HCl to pH 2, heated to boiling and allowed to cool. The pH of the solution was adjusted to 11 with 5% NaOH and the solution was re-boiled for 5 min, allowed to cool and filtered. The filtrate was adjusted to pH 6 with 5% HCl and diluted to 100 mL with water. A 200 µL portion of the resulting solution was injected into an aqueous carrier stream (6 ml/min) and merged with a stream (2 ml/min) of 2% NaOH and then with a stream (1 ml/min) of Folin-Ciocalteu reagent of pH 4-5 (1:4). The mixture passed through a 150 cm reaction coil and the absorbance was then measured at 670 nm. A diagram of the manifold used is given. The calibration graph was linear from 5-100 mg/l of tannin; the detection limit was 1.04 mg/l. The RSD (n = 10) was 2.9%. The throughput was 250 samples/h.
Tannins Polyphenols Spectrophotometry pH