[KoRuPT]

I'm tasked with quantifying the amount of Protoporphyrin IX in brown egg shells.

To extract the pigment from the eggshell, we are using a biphasic mixture of HCl and ethyl acetate. After some time, most of the pigment is extracted into the organic layer, and we record the UV-Visible spectrum of the extract.

I read that Protoporphyrin IX is converted by an enzyme to Heme, a cofactor of hemoglobin. The enzyme catalyzes the reaction of Protoporphyrin IX with ferrous iron. I can't seem to find a way to measure Protoporphyrin IX directly, so I was considering reacting it with ferrous iron to convert it through Heme, which could then be measured. I found an article here where the document some of the assays used to quantify heme, but I can't access it without having a paid membership to the database. Does anyone have any other ideas, or any links that can help me find a good method to do this? Thank you for any and all help.