Applying the silver‐tube introduction method for thermal conversion elemental analyses and a new δ 2 H value for NBS 22 oil

The delta(2)H(VSMOW-SLAP) value of total hydrogen of the international measurement standard NBS 22 oil was determined by a new method of sealing water in silver tubes for use in a thermal conversion elemental analysis (TC/EA) reduction unit. The isotopic fractionation of water due to evaporation is virtually non-existent in this silver-tube method. A new value for the delta(2)H(VSMOW-SLAP) of NBS 22 oil, calibrated with isotopic reference waters, was determined to be -116.9 +/- 0.8 per thousand (1sigma and n = 31).