Affordable Access

Publisher Website

Fluorescent labeling of drugs and simple organic compounds containing amine functional groups, utilizing dansyl chloride in Na2CO3buffer

Authors
Journal
Journal of Pharmacological and Toxicological Methods
1056-8719
Publisher
Elsevier
Publication Date
Volume
45
Issue
3
Identifiers
DOI: 10.1016/s1056-8719(01)00157-5
Keywords
  • Cocaine
  • Dansyl Chloride
  • Fluorescence
  • Heroin
  • Methods
Disciplines
  • Chemistry

Abstract

Abstract Fluorescent labeling of amine functional groups using dansyl chloride (DNS-Cl), and in sodium carbonate buffer, allowed the detection of 1 μg amounts of analytes. The methodology presented allows dansylation of primary, secondary, and tertiary amine groups at a temperature of 25° C. The dansylation of tertiary amines involves a chemical reaction which removes one substituent (or branch) of the amine group. A one molar working concentration of Na 2CO 3 is used, and is at pH 11.0. Compounds such as isopropylamine, dipropylamine, diethylamine, triethylamine, triisooctylamine, and N,N-dimethylaniline were labeled by use of DNS-Cl from samples obtained from a complex mixture of alkanes. The compound p-chloroaniline contains a primary amine group and is a solid at 25°, quickly dissolves in the one molar sodium carbonate buffer and is dansylated in 15 min. Heroin, which contains a tertiary amine group, was extracted into ethyl acetate from an aqueous solution, then reacted with DNS-Cl. Benzocaine, a local anesthetic, was dansylated in 15 min. Tertiary amine groups incorporated in a rigid ring system, such as for caffeine, strychnine, and the ionic salt form of cocaine hydrochloride did not react with DNS-Cl under these conditions. The reaction time for tertiary amines was 2 h or less, and 15 min for compounds having primary and secondary amine groups. Separation of the dansylated compounds from unreacted DNS-Cl was accomplished by diethyl ether extraction of the aqueous reaction solution, followed by thin layer chromatography using various organic solvents such as acetone and methylene chloride.

There are no comments yet on this publication. Be the first to share your thoughts.