METHOD OF SAMPLE PREPARATION OF BIOLOGICAL SAMPLES FOR QUANTITATIVE DETERMINATION OF IODINE Russian patent published in 2023 - IPC G01N25/48 G01N33/02 G01N33/49 G01N33/493 G01N33/50 

FIELD: analytical chemistry.

SUBSTANCE: invention relates to the methods of sample preparation of biological samples for further determination of iodine. The method of sample preparation of a biological sample for the quantitative determination of iodine involves adding to the sample concentrated nitric acid sequentially cooled to -10°C and below, and taking for 1 part of the sample 2.5 to 50.0 parts of acid and cooled to +4°C and below; taking concentrated hydrogen peroxide with 0.5 to 10.0 parts of hydrogen peroxide taken per 1 part of the sample. The resulting mixture is subjected to thermal decomposition, while within 5–20 minutes the mixture is heated to 100–120°C, then kept at 100–120 for 10–30 minutes°C, then heated to 130–150 for 5–10 minutes°C, then kept for 5–20 minutes at a temperature of 130–150°C. Then the mixture is cooled to 20°C.

EFFECT: proposed method of sample preparation of a biological sample ensures a decrease in the level of total mineralization of the sample below 0.3 g/l, which increases the sensitivity of methods of determining iodine by reducing the matrix effect and increases the service life of equipment for elemental analysis.

1 cl, 3 ex