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: Beverage -> non alcoholic -> nutritional

Citations 2

"Post-column Reaction Of Amino-acids With The Pentane-2,4-dione - Formaldehyde System For Their Automated Analysis"
J. Chromatogr. A 1985 Volume 318, Issue 2 Pages 367-372
Kazuaki Kakehi, Tadao Konishi, Ikuo Sugimoto and Susumu Honda

Abstract: The amino-acid sample is separated on a glass column (40 cm x 9 mm) packed with Hitachi 2611 resin with gradient elution from 0.2 M citrate buffer (pH 3.25) to 1.2 M citrate buffer (pH 5.28) at a flow rate of 1.0 mL min-1. The eluate is treated with 6% pentane-2,4-dione solution and 9% formaldehyde solution, both in 1 M acetate buffer (pH 6.22) in a PTFE coil (30 m x 0.5 mm) at 95°C, and the fluorescent reaction products are detected at 476 nm (excitation at 417 nm). The detection limits for glycine(I) and lysine(II) are 342 and 267 pmol, respectively; calibration graphs are rectilinear for 5 to 500 nmol of serine, I or II, and the coefficient of variation (at 50 nmol) are <5%. The method was applied to a nutritional drink, chymotrypsinogen and insulin acid hydrolysates and normal human urine.
Amino Acids Glycine Lysine HPIC Fluorescence Heated reaction Post-column derivatization Resin

"Application Of Flow Injection Analysis To The Determination Of Germanium"
Chem. Pharm. Bull. 1989 Volume 37, Issue 4 Pages 1095-1096
Shimada, K.;Nakajima, M.;Wakabayashi, H.;Yamato, S.

Abstract: Sample solution (50 µL) is injected into a carrier stream of ethanol (0.5 mL min-1) that then merges with a stream (0.42 mL min-1) of 0.002% phenylfluorine solution in ethanolic 0.43% HCl. After passage through a PTFE reaction coil (3 m x 0.5 mm) in an oil bath at 40°C, the absorbance is measured at 508 nm. The calibration graph was rectilinear up to 500 ng of Ge, and the coefficient of variation (n = 5) for 100 to 500 ng was 2%. The method was applied to a commercial health beverage with use of the method of standard additions. Interference was generally negligible.
Germanium Spectrophotometry Interferences Standard additions calibration Heated reaction