Patent ID: 8114671

Claim:
A method for quantifying a permanganate-reducing compound (PRC) content of an acetic acid sample, comprising: (a) measuring a permanganate absorbance of a reaction mixture comprising a known amount of a standard permanganate solution and the acetic acid sample at a selected wavelength from 460 nm to 580 nm at a set reaction time wherein the permanganate absorbance is determined by determining manganese dioxide absorbance and subtracting the determined manganese dioxide absorbance from the absorbance of the mixture; (b) adding a known concentration of PRC to the acetic acid sample to produce a spiked sample; (c) repeating step (a) with the spiked sample to measure the absorbance of the reaction mixture of the spiked sample (A sp ); (d) measuring the permanganate absorbance of a blank sample (A BL ) and (e) determining the PRC content of the acetic acid sample by: [PRC] AA =( A BL −A AA )×[PRC] sp /( A AA −A sp ), wherein [PRC] AA is the PRC content of the acetic acid sample, [PRC] sp is the spiked PRC concentration, A sp is the absorbance of the reaction mixture of the spiked sample and the standard permanganate solution, A AA is the permanganate absorbance of the reaction mixture of the acetic acid sample and the standard permanganate solution, and A BL is the permanganate absorbance of the mixture of the blank sample and the standard permanganate solution.