Quantifying hydrogen peroxide in iron-containing solutions using leuco crystal violet

Table 1 LCV method details.^a

Reagent	Reagent preparation	Stock concentration	Volume added (μl)	Final concentration
Sample^b	...	...	1700	...
KH₂PO₄	136.07 g + 0.5 L H₂O	1 M	200	100 mM
pH buffer	pH adjusted to 4.2 with H₃PO₄
LCV	31 mg LCV + 30 ml H₂O + 19.2 ml of 0.25 N HCl	1.65 mM	50	41 μM
HRP	4.0 mg HRP + 50 ml H₂O + 92 μl of 1 M sodium azide	0.08 mg/ ml (14.4 units/ml)	50	1 μg (0.18 units)

^aReagent preparations, concentrations, volume added, and final concentrations of the solutions added to a 4 ml cuvette and kept in the dark before analysis. Reagents listed in order of addition. H₂O₂ calibration solutions were prepared by dilutions of a stock.
^bSamples containing pyrite were filtered.

ISSN: 1467-4866