A continuous-flow crushing device for on-line delta H-2 analysis of fluid inclusion water in speleothems

A method for the isotope analysis of fluid inclusion water in speleothem calcite is presented. The technique is based on a commercially available continuous-flow pyrolysis furnace (ThermoFinnigan TC-EA). The main adaptation made to the standard TC-EA configuration is the addition of a crusher and cold trap unit, which is connected to the carrier gas inlet at the top of the TC-EA reactor tube. A series of tests conducted with this device shows that: (1) standard waters, injected in the crusher, and passed through a cryogenic trapping routine, yield accurate delta H-2 values; (2) crushed cubes of speleothem calcite from two Peruvian caves with rather dissimilar seepage water delta H-2 values yield fluid inclusion delta H-2 values in good accordance with these drip waters. The clear advantage of this continuous-flow technique for fluid inclusion isotope analysis is that it is relatively quick compared with other techniques. Since the conditions of water sample introduction into the TC-EA are identical for delta H-2 and delta O-18 analysis, we expect that only limited adaptations to the extraction procedure are required to provide delta O-18 analysis of fluid inclusion samples with the same device. Copyright (c) 2006 John Wiley & Sons, Ltd.