There, he conducted research on the natural preservation of carbohydrates in marine sediments and the consequences for its preservation on the chemical and carbon isotopic composition of sedimentary organic matter. His research showed that preservation through sulfurization is a more important mechanism for the preservation of organic carbon than previously thought. The enhanced contribution of normally labile organic carbon can have substantial impacts on total organic carbon (TOC) records. In addition, the difference in δ13C between carbohydrates and lipids within single organisms is much larger than previously realized indicating that preservation of carbohydrates can also cause substantial changes in δ13CTOC records.