| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: method of determining amount of choline chloride in premixes involves collecting samples, grinding and establishing content of choline chloride in the premix. The novelty lies in designing a "piezoelectric pump" type detector based on 6 piezoelectric quartz crystal resonators with fundamental oscillation frequency of 10 mHz, whose electrodes are modified by applying onto their surface films of the following standard chromatographic sorbents and indicators weighing 15-17 mcg: dinonyl phthalate, 4-aminoantipyrene, polyethylene glycol phthalate, dicyclohexane-18-crown-6, polyethylene glycol sebacate, methyl red. A sample weighing 2 g is then collected from mass heated to temperature 302C, put into a 20 cm weighing bottle with a polyurethane membrane on the cap and held for 30 minutes. 1 cm3 of an equilibrium phase under the premix is collected using a syringe through the polyurethane membrane and then quickly injected into the static "piezoelectric pump" cell. The oscillation frequency of the piezoelectric quartz crystal resonators (with films) is simultaneously recorded with a 5 second interval for 35 seconds and a composite signal is generated in form of a kinetic "visual imprint". The area of the said imprint is calculated and content of choline chloride is determined from a calibration curve plotted in coordinates of the area of the "visual imprint" versus its content in the premix. ^ EFFECT: high accuracy of detecting choline chloride in premixes. ^ 1 dwg, 1 tbl, 2 ex |
