title: A sensitive spectrofluorimetric method for the quantification of melamine residue in milk powder using the Mannich reaction in aqueous solutions.
abstract: The objective of this study was to develop a spectrofluorimetric method for the quantitative determination of melamine. The method was based on the complexation of melamine with a mixture of formaldehyde and chemicals including a ketone group, as described by the Mannich reaction. The complex was determined by spectrofluorimetric measurement as it is characterized by specific spectroscopic properties that are related to the chromophore of the ketone compounds. 1,3-Diphenylpropane-1,3-dione (DPPD) was tested as a ketone compound. The fluorescence spectrum of the complex presented a maximum of absorption at 325 nm.A quenching of the fluorescence occurred when melamine was added into the solution. The kinetic of fluorescence quenching was followed to determine quantitatively the melamine concentration. An internal standard was added to quantify melamine. The method was tested to determine the level of melamine in contaminated milk powder. The recovery value was 97% and the limit of detection was 0.007 μg mL(-1.)
authors.affiliation: Laboratory of Physical Chemistry of Environmental Engineering and Biology, Faculty of Science II, Lebanese University, P.O. Box 26110217, Fanar, Lebanon. Electronic address: jamil.rima1@gmail.com.
authors.forename: Jamil
authors.initials: J
authors.lastname: Rima
authors.forename: Karine
authors.initials: K
authors.lastname: Assaker
authors.forename: Fawaz
authors.initials: F
authors.lastname: El Omar
authors.forename: Chawki bou
authors.initials: Cb
authors.lastname: karim
mesh_terms: D000818:Animals; D002138:Calibration; D047188:Chalcones / Q000737:chemistry*; D005453:Fluorescence; D005506:Food Contamination; D005557:Formaldehyde / Q000737:chemistry*; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014227:Triazines / Q000302:isolation & purification*
chemical_list: D047188:Chalcones; D014227:Triazines; D005557:Formaldehyde; C011907:melamine
keywords: Internal standard addition method; Mannich reaction; Melamine; Quantification; Sensitivity; Spectrofluorimetric