High-precision δ¹³C and δ¹⁸O analysis of carbonate microfossils such as foraminifera depends on treating every sample and standard identically, but the dehydrated phosphoric acid used for digestion is highly viscous and difficult to deliver reproducibly.

This Technical Note shows how the direct-motor-driven, valveless pump used on the iso CARB PREP, iso MULTI PREP and iso FLOW delivers this acid into the sample vial efficiently and reliably.