METHOD OF DETECTING METHYL ACETATE VAPOUR IN PRESENCE OF BENZYL ACETATE IN WORKPLACE AIR

摘要

FIELD: chemistry.;SUBSTANCE: method of detecting methyl acetate vapour in the presence of benzyl acetate in workplace air involves taking a sample, preparing the detection equipment for operation, putting the sample into a detection cell, picking up the analytical signal and calculation of concentration of methyl acetate using an analytical curve. The sample is put into a detection cell with a piezoelectric crystal resonator whose electrodes are pre-modified by through application of a sorbent solution of polyethylene glycol succinate in ethanol such that the mass of the film after removal of the solvent in a drying chamber for 30 minutes at 40°C is between 16 and 20 mcg. The analytical signal is picked up after putting the sample into the detection cell in form of the response of the modified electrodes of the piezoelectric crystal resonator, calculated from the difference in its oscillation frequency before putting the sample into the detection cell and after establishing equilibrium in the sorption system with the added sample. Concentration of methyl acetate is calculated based an analytical curve of concentration versus the said response using the equation C=3.7ΔF, where C is methyl acetate concentration, mg/m³; ΔF is response of modified electrodes of the piezoelectric crystal resonator.;EFFECT: more rapid, mobile and accurate measurement due to use of a piezoelectric crystal resonator, modified with a film of polyethylene glycol succinate deposited from a solution in ethanol and which exhibits sorption affinity to methyl acetate; also, deposition of a film with sorbent mass of 16-20 mcg on the strain-sensitive area of the piezoelectric resonator increases sensitivity and reduces errors.;3 ex