using
a Fe (III) standard curve. The PV of the sample was obtained using
the following equation:
PV ¼ ðAsm AblÞ=ð55:84 2 S WsmÞ DF ð2Þ
where Asm is the absorbance of the sample at 470 nm, Abl is absorbance
of the blank at 470 nm (both absorbance was corrected from
subtracting absorbance at 670 nm); S is slope of the Fe (III) calibration
plot; 55.84 is atomic weight of Fe; 2 is factor to convert milliequivalents
(meq) of Fe to meq of peroxide; Wsm is sample weight
in grams; and DF is the dilution factor of 2.5. The experiment was
conducted in duplicate.