Automated analysis of gases stored in Vacutainer vials

Trace gas research is often constrained by the number of samples to be analyzed. We report here, modifications to a commercially available headspace gas autosampler for sampling stored gas in blood collection vials (Vacutainer Brand). The sampler was modified to: a) accommodate a 0.5‐mL gastight syringe, b) accept 3‐mL Vacutainer vials, and c) ensure the syringe needle dislodged from the vial septum. Sample volumes using the modified sampler were consistent from vial to vial. For the determination of the nitrous oxide (N2O) concentration of a known reference, we found a coefficient of variation of 3% with the modified autosampler compared to 1% with manual injections. The modification of two autosamplers has permitted analysis of 90 sample vials per day for N2O, carbon dioxide (CO2), oxygen (O2), acetylene (C2H2), and nitrogen (N2) gases using one gas Chromatograph with two detector systems. As a consequence, we have increased sample numbers, reduced associated labour costs and maintained analysis quality.