Background: Monitoring of DA, in the presence of other chemical analogues such as epinephrine,
norepinephrine, serotonin, ascorbic acid, uric acid, catechol, phenethylamine, tyramine, and
tyrosine, is crucial in the diagnosis and mechanistic understanding of human neuropathology. Therefore,
the determination of DA at trace levels has become a very important analytical task, as part of health safety and
Introduction: A cloud point extraction (CPE) process was developed for the isolation and detection of
dopamine in food, urine, and pharmaceutical samples.
Methods: In this procedure, dopamine was derivatized with o-phthalaldehyde (OPA) and sodium
sulphite in aqueous solution. The isoindole derivative was synthesized by the reaction of OPA and sodium
sulphite with the amino group of dopamine and the resulted isoindole derivatives were extracted
by cloud point extraction. After extraction process, the concentration of enriched analyte was measured
by UV-VIS spectrophotometry. The parameters affecting the CPE such as concentration of surfactant
and electrolyte, equilibration temperature and time and pH of sample solution were investigated.
Results: After optimization of the CPE conditions, the linear range of 8-80 µM (without extraction 100-
1000 µM) was established for dopamine with detection limit at 2.6 µM.
Conclusion: The developed extraction procedure was applied to the quantification of dopamine in
chocolate, urine, and pharmaceutical samples. The study ensures a promising strategy for the detection
of dopamine in the presence of biological constituents, e.g. ascorbic acid, uric acid, and serotonin.