The temperature of maximum pyrolysis yield (known as Tmax) can be used to determine the level of thermal alteration in sedimentary organic matter; higher Tmax values represent higher thermal alteration. Tmax is commonly measured on petroleum source rocks or similar sediments with high organic carbon contents. It would be desirable to measure the Tmax of volcanic sediments because they can have complex patterns of thermal alteration. However, volcanic sediments often have low total organic carbon contents and consequently are susceptible to analytical interferences. Despite this, it can be shown that meaningful Tmax measurements can still be made in sediment with organic carbon contents as low as 0.2% and that interference caused by bitumen or ionizable salts can be mitigated by solvent extraction and rinsing with water. Thus, it is reasonable to use temperature programmed pyrolysis to assess levels of thermal alteration in even low total organic carbon volcanoclastic sediments.

One of the commonly used analytical approaches for measuring oxygen isotope ratios δ18O of solids (organic and inorganic) is to pyrolyze the samples to gaseous phases and then send the gas into an isotope ratio mass spectrometer system. Solid samples for δ18O measurements are usually stored in silver cups because of its low reactivity towards oxygen and other oxidants. Samples in silver cups can be dropped directly into the carbon column of the pyrolysis furnace. However, the silver cups can tarnish and then be oxidized over a prolonged storage period. We find that while a small amount of silver oxides does not affect measurements with appreciable sample sizes, it can skew isotope results of small samples. We thus recommend careful storage of samples in silver cups to minimize oxidation, such as under an air-isolated condition, and avoiding prolonged storage for accurate δ18O measurements.