Fluorescamine stabilization

A variety of procedures are available for staining paper and thin-layer plates with fluorescamine after chromatography or electrophoresis. Spraying thin-layer plates with a solution of triethylamine, both before and after spraying with fluorescamine, stabilizes the fluorescent spots (Felix and Jimenez, 1974). A sensitivity of 10 pmol was achieved for peptides by dipping thin-layer chromatograms into a solution of fluorescamine in acetone-hexane (1 4) (Nakamura and Pisano, 1976). Somewhat poorer sensitivity for peptides was found with o-phthalaldehyde, and these fluorophors decomposed after several hours (Mendez and Gavilanes, 1976). Peptides prelabeled with fluorescamine have also been resolved on thin-layer plates (Imai et aU 1974). 

Tnethylamine ammo acids as fluorescamine denvatives stabilization spray solution, 10% in dKhloromethane, employed before and after (imctinn with... 

Stabilized protein bands are excised and hydrolyzed in constant-boiling hydrochloric acid containing thioglycolic acid. The hydrolysate is evaporated, and the residue is dissolved and used for amino acid analysis. This procedure has not been highly successful with conventional amino acid analyzers, mainly because of the large amounts of ammonia released from the gel during hydrolysis. The ammonia interferes with the analysis of lysine and histidine by both ninhydrin and o-phthalaldehyde. Fluorescamine yields low fluorescence with ammonia, and, although an ammonia peak appears, it does not interfere with the analysis of the basic amino acids. 

MDPF is closely related in structure to fluorescamine. Both primary and secondary amines react with MDPF in acetonitrile, but only primary amines form fluorescent pyrrol inones. Secondary amines form non-fluorescent aminodienones. By reacting with ethanolamine, the latter produce fluorescent products. Their stability is adequate for chromatographic separation [258, 259]. 

Fluorescamine (A) triethylamine (10%, v/v) in dichloromethane (B) fluorescamine (4-phenyl-spi ro[f u ran-2-(3H), 1 -phthalan]-3,3 -dione) (0.05%, m/v) in acetone Plate sprayed with A, air-dried, sprayed with B, air-dried, then sprayed again with A spraying with base is necessary to stabilize and intensify fluorescence Spedlic for amino- and acetamidodeoxy sugars fluorimetric scanning (excitation 390 nm, emission 475 nm) 50-100pmol... 

Sulfonamides are used for the prevention and treatment of human infectious diseases and also as growth promoters in swine. It is necessary to monitor pork products for drug residues of sulfonamides. Various sulfonamides were separated on Whatman LKCigF layers in a methanol-0.5 M NaCl (50 50) mobile phase spots were detected with UV light (366 nm) after spraying with fluorescamine reagent followed by 0.5% triethanolamine in chloroform to stabilize fluorescence. The Rp values of the sulfonamides were as follows sulfabromomethazine, 0.19 sulfadimethoxine, 0.39 sulfamethazine, 0.59 sulfathiazole, 0.76 sulfaguanidine, 0.90 (Whatman TLC Technical Series, Volume 3). 

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