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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Classification: Organic compound -> alcohol -> ethoxylate

Citations 1

"Measurement Of Carbonyl Compounds As The 2,4-dinitrophenylhydrazonate Anion. Reaction Mechanism And An Automated Measurement System"
Anal. Chem. 1994 Volume 66, Issue 13 Pages 1965-1970
Purnendu K. Dasgupta, Genfa Zhang, Shawn Schulze, and John N. Marx

Abstract: Formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, p-(dimethylamino)benzaldehyde, glyoxal (I), acetone, benzoylacetone (II), 2,3-butanedione, 2,4-pentanedione (III), isovaleraldehyde or methylisobutylketone were dissolved in methanol and portions (18 µL) were injected into a carrier stream (~1 ml/min) of methanol. This merged with a stream of 2,4-dinitrophenylhydrazine (DNPH; 200 mg in 50 mL of methanol and 4 mL of concentrated HCl, diluted to 100 mL with H2O) and passed to a PTFE reactor coil (300 cm x 0.3 mm i.d.) at 60°C for 18 min. Reaction with 10% KOH in methanol/H2O (4:1) then took place in a second reaction coil (300 cm x 0.72 mm i.d.) at 60°C for >90 s, and the resulting quinonoid anion was detected at 470 or 480 nm. Calibration graphs were linear over two orders of magnitude for C21-C9 aliphatic carbonyl compounds and the detection limit was 0.5 mg/l; sample throughput was 20/h. I precipitated and ketones II and III failed to react sufficiently. The mechanism of the base-catalyzed decomposition of DNPH was investigated by NMR (details given). The method was applied to an alcohol ethoxylate sample.
Carbonyl compounds Formaldehyde Acetaldehyde Propionaldehyde Benzaldehyde 4-Dimethylaminobenzaldehyde Glyoxal Acetone Benzoylacetone 2,3-Butanedione Pentanedione, 2,4- Isovaleraldehyde Methyl isobutyl ketone Spectrophotometry Heated reaction Organic phase detection