DETERMINATION OF OLEIC AND PALMITIC ACIDS IN COMPOSITION OF TRIACYLGLYCEROLS OF VEGETABLE OILS USING PIEZOELECTRIC SENSORS MODIFIED WITH MOLECULAR IMPRINTING POLYMERS
The method of production polymers with molecular imprinting of oleic and palmitic acids on the basis of polyimides PM, which is a mixture of initial monomers 1,2,4,5-bezalternativno acid and 4,4'-diaminodiphenyloxide, is developed. The analysis of oleic and palmitic acids in solutions is made by piezoelectric sensors, which are modified by a polymer of comparison, a polymer with molecular imprints of oleic acid and a polymer with molecular imprints of palmitic acid. Linear calibration graphs with high determination coefficient are observed in MIP on the basis of PM. Comparing values of imprinting factor and selectivity coefficients of the obtained polymers showed, that high values are observed for sensors in the determination of the fatty acid, which was used as a template in the synthesis of MIP. Piezoelectric sensors based on molecular imprinting polymers (MIP) of oleic (MIP-Oleic) and palmitic (MIP -Palmitic) acids to determine these fatty acids in oils were tested. The chromatography-mass spectrometry (Agilent Technological 7890B GC Systems with mass selective detector Agilent Technological 5977А MSD) was used as a method of comparison. Developed piezoelectric sensors are tested in the analysis of sunflower oil, which is handicraft produced. The correctness of the oleic and palmitic acids identification is tested by the method "introduced - found". The chromato-mass-spectrometry is used as a method of comparison. The difference between the results of the determination of acids by sensors based on PAA and by the method of chromato-mass-spectrometry does not exceed 10 %.