Sedimentary sterols and steryl chlorin esters: distribution differences and significance

The sterol distributions in the steryl chlorin esters (SCEs) from three marine and two lacustrine sediments have been compared with the free sterols and known water column sterol distributions. The comparison provides further evidence that the SCE sterol distributions are more representative of the original phytoplanktonic sterol distribution than are the free sterol distributions. This is most clearly seen in the relative abundance of C26 sterols and 4-methyl sterols, and in the stanol/stenol ratios. It appears that in general the SCE sterols are less susceptible to selective biodegradation than the free sterols.