METHOD FOR QUANTITATIVE DETERMINATION OF ORGANIC IMPURITIES IN BENZO-CROWN ETHERS Russian patent published in 2014 - IPC G01N30/00 

FIELD: chemistry.

SUBSTANCE: chromatographic method used to determine organic impurities in benzo-crown ethers is gas-liquid chromatography, which includes a step of mixing a solution of the analysed benzo-crown ether with a standard substance (unsubstituted crown ethers). The method includes collecting an analysed sample, evaporation thereof and passing in a current of an inert carrier gas through a capillary chromatographic column. Signals are then detected by a flame-ionisation detector. The analysed benzo-crown ether is used in the form of a (1-4)% solution in a polar solvent, and the standard substance is used in the form of a 1% solution in the same solvent. After mixing, the obtained mixture is stirred at (30-70)°C. The sample collected from said mixture is evaporated and passed in a current of an inert gas at a rate of (2.6-3.2) cm³/min with stream division of (1:10)-(1:25) through a quartz capillary chromatographic column with an inner diameter of (0.25-0.5) mm and length of (15-30), having a film-type liquid stationary phase containing 5% phenyl polysiloxane and 95% dimethyl polysiloxane. After stirring the analysed substances, centrifuging is optionally carried out at a rate of 5000-6000 rpm. Quantitative determination of organic impurities in dibenzo-18-crown-6 is carried out in the following temperature conditions: initial column temperature 150°C, final column temperature 300°C, rate of temperature increase 20°C/min, evaporator temperature 350°C, detector temperature 370°C; and in dibenzo-21-crown-7 at initial column temperature 180°C, final column temperature 340°C, rate of temperature increase 10°C/min, evaporator temperature 390°C, detector temperature 400°C.

EFFECT: higher threshold of detecting organic impurities and faster analysis.

6 cl