Dear all, I have been analyzing some sediment samples from mangroves for C and N isotopes on a Flash EA - Delta V plus setup, and I have noticed that after running a number of them (about 50) the oxidation tube cracks at the chromium oxide band. This does not happen with any other samples. In addition, these same samples tend to clog the stainless steel lines, and apparently also damage the gc column. Not the kind of sample I wish to run often. Does anyone have an idea of the possible reason for such phenomena?
Thank you,

Matheus C. Carvalho
Senior Research Associate
Centre for Coastal Biogeochemistry Research
Southern Cross University
Lismore, NSW, Australia