METHOD OF DETERMINING 4-NITROANILINE IN BIOLOGICAL MATERIAL Russian patent published in 2014 - IPC G01N33/52 

FIELD: chemistry.

SUBSTANCE: 4-nitroaniline-containing biological object is twice infused with organic isolating agent, represented by 1,4-dioxane; obtained extracts are combined; combined organic extract is evaporated until solvent is completely removed; residue is multiply processed with acetone; acetone extracts are separated, combined; solvent from combined extract is evaporated; residue id dissolved in acetonitrile; acetonitrile solution is dissolved with buffer solution with pH 9-10 in ratio 1:4 by volume; solution is processed with potassium chloride, extracted with ethylacetate saturated with water; obtained extract is evaporated in air flow at temperature 18-22°C until dry residue is obtained; residue is dissolved in mixture of tetrachloromethane and acetone taken in ratio 9:1 by volume, chromatographed in column with silicagel L 40/100 mcm with application of mobile phase of tetrachloromethaneacetone in ratio 9:1 by volume; eluate fractions, containing analysed substance, are combined; eluent is evaporated in air flow at temperature 18-22°C until solvent is completely removed; residue is dissolved in dichloromethane, processed with derivate-forming reagent, represented by N-tert-butyl-dimethylsilyl-N-methyltrifluoroacetamide, for 20 minutes under conditions of heating at temperature 60°C, and determination is carried out by chromatography-mass-spectrometry method with application of capillary column DB-5 MS EVIDEX with stationary phase, representing 5%-phenyl-95%methylpolysiloxane, with application of mass-selective detector, operating in electron impact mode; starting temperature of column thermostat is 70°C, said temperature is preserved for 3 minutes, with further increase of temperature from 70°C to 290°C at rate 20°C per minute, final column temperature is preserved for 16 minutes, injector temperature is 250°C, quadrupole temperature is 150°C, detector interface temperature is 300°C; intensity of signal caused by charged particles, formed in the process of bombardment of analysed substance, output from capillary column and supplied into ion source, with ionising beam of electrons with energy 70 eV, is registered; mass-spectrum by total ion current is registered and quantity of 4-nitroaniline is calculated by area of chromatographic peak of its trimethylsilyl derivative.

EFFECT: increase of sensitivity.

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