A contribution to common Carius tube distillation techniques

Abstract

In this paper, we introduce an economic electrothermal timing steamer for common Carius tube Os in situ distillation. It is suitable for analysing several batches of samples. Its configuration allows the Carius tubes to be properly fixed and bathed in steam into which the tubes are immersed. The top of each Carius tube is sealed with a stretchy rubber head through which a pair of teflon tubes pierce, serving as inlet and outlet for clean air and OsO₄ respectively. At steam temperatures of 99–100 °C, OsO₄ in the sample solutions inside the Carius tubes is evaporated out and subsequently carried by clean air to the trapping water in an ampoule bottle, immersed in a box filled with ice. In the present study the steamer allowed for the convenient, efficient and simultaneous distillation of Os from seven samples with near ninety percent recovery. The blank values were 0.42 ± 0.15 pg and 0.26 ± 0.05 for ¹⁸⁷Os and ¹⁸⁷Os/¹⁸⁸Os (n = 4). The dating results of reference materials (RMs) namely Henderson, HLP and JDC were in accordance with reference and certified values within the range of uncertainties. The special steamer has successfully been used in the analysis of pyrite samples for the distillation of Os.