METHOD OF CONCENTRATING SULFOAZO DYE E102 FROM AQEOUS SOLUTION Russian patent published in 2010 - IPC C09B61/00 

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry of organic compounds and can be used to concentrate sulfoazo dye E102 during analytical inspection of aqueous media and food products. The invention describes a method of concentrating sulfoazo dye E102 from an aqueous solution, involving addition of crystalline ammonium sulphate to the aqueous solution of sulfoazo dye E102 until achieving 42-43 wt % salt concentration in the solution and adding polyethylene glycol PEG-5000 in amount of 1% of the weight of the initial solution. The obtained mixture is weighed (m_tot), extracted for 10 minutes, centrifuged for 30 minutes at 2000 rpm and the dye concentrate is separated from the aqueous phase (m_org). The concentration coefficient (under the condition of virtually complete extraction R=96-99%) is calculated as a ratio: K=m_aq./t_org., where m_aq. and m_org. are mass of the aqueous and organic phase respectively.

EFFECT: method provides virtually complete extraction of sulfoazo dye E102 from an aqueous solution through single-step extraction and its 50-times concentration using environmentally safe polyethylene glycol PEG-5000.

1 cl, 1 ex