Use of drain cleaner in processing shale samples

Abstract

We have been processing organic-rich shale from the Carboniferous Luocheng Formation, Peoples Republic of China, for microcrinoids and microgastropods. Initial attempts to disaggregate the shale using standard techniques (e.g., chlorine bleach, Quaternary-O, paint thinner, Stoddard's solution) proved futile. Nothing worked on the mixed organic/clay matrix in which the fossils were entombed. One particularly frustrating evening, a television commercial, in which a large hair clog in a clear plastic drain pipe was dissolved, inspired us to purchase and try some drain cleaner for processing our samples. After reading numerous drain-cleaner labels, we selected Liquid-plumr® because it contained one of the strongest concentrations of sodium hypochlorite and sodium hydroxide easily available. We are not necessarily recommending Liquid-plumr® over other brands; however, some drain cleaners are nothing more than concentrated sulfuric acid, so careful scrutiny of the labels is recommended.