I want to do the PV using spectrophotometric method. The problem is that linear curve of cumene hydroperoxide can not be able to obtain. Later, i find in some paper, chloroform is having high absorbance in blank reading. Chloroform with ethanol as preservatives is recommended. In another paper, it is mentioned about the modified method of Richards and Hultin (2002) along with the concentration range of cumene hydroperoxide.
please try this
Peroxide value (PV)
. To 1 mL of emulsion sample, 2 mL of chloroform/methanol (2:1, v/v) were added and mixed using a vortex mixer for 3 s to separate the sample into two phases. The organic solvent phase (20 μL) was mixed with 2.35 mL of chloroform/methanol (2:1, v/v), followed by 50 μL of 30% ammonium thiocyanate (w/v) and 50 μL of 20 mM ferrous chloride solution in 3.5% HCl (w/v). After 20 min, the absorbance of the coloured solution was read at 500 nm using a spectrophotometer (Shimadzu, Kyoto, Japan). Blank was prepared in the same manner, except the distilled water was used instead of ferrous chloride. PV was calculated after blank substraction and expressed as mg cumene hydroperoxide/liter (L) of emulsion. A standard curve was prepared using cumene hydroperoxide with the concentration range of 0.5–2 ppm.
Thanks for your valuable suggestion! I will follow this protocol.
Sorry, I have a question in this regard.
Could we use FeCL3 for preparation of standard curve? I cant find any references except Shantha and Decker (1994).
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