URINE SAMPLE PREPARATION METHOD FOR DETERMINING MONOMETHYLPHTHALATE, MONOETHYLPHTHALATE, MONOBUTYL PHTHALATE, MONOBENZYL PHTHALATE, MONOETHYLHEXYLPHTHALATE BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY / MASS SPECTROMETRY Russian patent published in 2019 - IPC G01N33/493 G01N1/28 

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry. Method of preparing a urine sample for monophthalate determination by HPLC / mass spectrometry involves centrifuging a urine sample for 10 minutes at rate of 2,000 rpm. Then concentrated acetic acid is added to the sample until mixture pH reaches 4.8, then to 5 cm³ acidified sample is added with 0.2 cm³ aqueous enzyme solution β-glucuronidase (Helix Pomatia). Obtained mixture is incubated at temperature of +37 °C for 24 hours, cooled and brought to pH 7 by adding 40 % sodium hydroxide solution. Mixture is centrifuged for 10 minutes at rate of 2,000 rpm and upper layer is selected in amount of 5 cm³. Using this upper layer, performing TFE on Oasis HLB 5cc cartridge in two steps: at the first stage, it is sequentially passed through it 1 cm³ methanol and 1 cm³ distilled water, produced plums are removed, applied on cartridge, centrifugation recovered upper layer of liquid in amount of 5 cm³, washing cartridge 1 cm³ 5 % methanol solution and passed through cartridge 0.5 cm³ acetonitrile while collecting the extract. At the second stage, the same cartridge is first washed successively with 1 cm³ 0.4 % sodium hydroxide solution, 1 cm³ 5 % methanol solution and produced drain is removed, then passed through said cartridge 0.5 cm³ acetonitrile, while attaching the obtained extract to the extract obtained at the first stage. Combined extract is filtered through a membrane filter with pore diameter of 0.2 mcm to obtain a urine sample prepared for analysis.

EFFECT: invention increases degree of extraction of monomethylphthalate (MMP) up to 100 %, monoethylphthalate (MEP) up to 94 %, monobutylphthalate (MBP) – 96 %, monobenzyl phthalate (MBzP) – 92 %, monoethylhexyl phthalate (MEHP) – 100 % with extraction error ±10 % and allows to expand range of measured concentrations of monophthalates from 10^-4 up to 10^-1 mg/dm³.

1 cl, 1 dwg, 8 tbl