Determination of metalloporphyrins in rocks, sediments and other geological materials using total reflectance spectrophotometry

This paper presents a high resolution method for obtaining diagnostic spectra of metalloporphyrins from geologic materials using total reflectance spectrophotometry. The technique is simple, straightforward and inexpensive, and does not require extracting the porphyrin from the material being investigated. Diffuse reflectance spectra from 250 to 850 nm have been measured for nickel, vanadium and copper porphyrins. Spectra of pure porphyrins, porphyrins mixed with geologic matrices and several hydrocarbon reservoir rocks are presented. These measurements may be valuable in determining the origin of organic material in rocks containing hydrocarbons.