title: Voltamperometric discrimination of urea and melamine adulterated skimmed milk powder.
abstract: Nitrogen compounds like urea and melamine are known to be commonly used for milk adulteration resulting in undesired intoxication; a well-known example is the Chinese episode occurred in 2008. The development of a rapid, reliable and economic test is of relevance in order to improve adulterated milk identification. Cyclic voltammetry studies using an Au working electrode were performed on adulterated and non-adulterated milk samples from different independent manufacturers. Voltammetric data and their first derivative were subjected to functional principal component analysis (f-PCA) and correctly classified by the KNN classifier. The adulterated and non-adulterated milk samples showed significant differences. Best results of prediction were obtained with first derivative data. Detection limits in milk samples adulterated with 1% of its total nitrogen derived from melamine or urea were as low as 85.0 mg · L(-1) and 121.4 mg · L(-1), respectively. We present this method as a fast and robust screening method for milk adulteration analysis and prevention of food intoxication.
authors.affiliation: Biosensors and Bioanalysis Lab, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN, CONICET, CABA 1428, Argentina. astrid@qb.fcen.uba.ar
authors.forename: Astrid
authors.initials: A
authors.lastname: Hilding-Ohlsson
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Fauerbach
authors.forename: Natalia J
authors.initials: NJ
authors.lastname: Sacco
authors.forename: M Celina
authors.initials: MC
authors.lastname: Bonetto
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cortón
mesh_terms: D000818:Animals; D003611:Dairy Products / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D011208:Powders / Q000737:chemistry*; D025341:Principal Component Analysis / Q000379:methods; D014227:Triazines / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*
chemical_list: D011208:Powders; D014227:Triazines; D014508:Urea; C011907:melamine
keywords: KNN; f-PCA; milk adulteration; rapid screening methods; voltammetry