Ramped PyrOx samples must be treated with acid to remove carbonate material

Why?

Organic matter may not be the only carbon bearing part of a sediment sample. Detrital carbonates, authigenic carbonate minerals, unpickable fragments of calcareous tests may interfer with interpretaions of organic carbon isotope properties. Thus we remove the mineral carbonates using a gentle acid bath to more clearly interpret organic carbon.

Samples are rinsed with 10% HCl at room temperature for 60 minutes to dissolve carbonates while minimizing hydrolysis of organic material. The sediment sample is rinsed numerous times until a pH of ~6 is reached. Samples are then dried in a low-temperature oven for 24 hours.

Clients can submit samples for acid treatment, or may elect to pretreat their samples prior to arrival at USF for a reduced rate.