ANALISYS OF RESIDUES OF VETERINARY SODIUM DICLOFENAC IN MILK THROUGH NEAR INFRARED SPECTROSCOPY

Abstract

Introduction: Milk is one of most consumed food by human beings, especially children and elderly. In 2007, the Federal Police conducted an operation that showed an enormous fraud scheme in industrialized milk in Brazil. In addition, they found out that 1/3 of the milk consumed in Brazil did not pass by inspection. There are several ways to adulterate milk, such as with addition of water, caustic soda, sodium chloride and others. However, there is another issue, that is, milk contamination with veterinary drugs. These drugs may be present in high concentrations in milk, in case the cow was milked in the clearance period. Contaminated milk can cause damages to consumers’ health or injury to the production of derivates. Objective: To develop a complementary technique to detect the presence of residues of veterinary drugs in milk samples. Material and Methods: currently, given the technological development, there are many techniques based on multielement analysis for studying the chemical components of different samples. This paper uses the technique of Fourier Transform Near Infrared Spectroscopy and the Principal Components Analysis (PCA) to detect the evidence of residues of veterinary drugs in milk. To this end, we simulated adulteration in milk with percentages of 0.1%, 0.5% and 10% drugs in milk. Results: cryoscopy: 0.539 ºH with 0.18% water; non-acid milk according to Alizarol test; pH 6.71; Fat: 3.25%; Protein: 3.01%; Lactose: 4.55%; Solids: 10.80%. Drug residues were observed via the first derivative of reflectance spectra and PCA analysis at levels below 1%. Conclusion: The result was positive indicating that the FT-NIR system can detected the residues of studied drugs within the simulated percentage. DESCRIPTORS Milk. Drug. Diclofenac. Spectroscopy, Near-Infrared.