The sampling of gases for subsequent trace oxygen determination is not straightforward. Whilst in theory quantification of oxygen at single 1 µL/L (ppm v/v) concentrations should be possible, in practice accurate, on-site measurements below 100 µL/L are rarely achieved due to system leaks and ingress of atmospheric oxygen (21% v/v) into the system.
It is therefore essential that the determination of trace oxygen in gas is carried out at-line (offshore or onshore gas processing facility).
Qa3 have developed a sampling apparatus and analysis protocol designed to (i) prevent contamination from atmospheric oxygen (ii) reduce equilibration time and (iii) achieve an LOQ for oxygen that is commensurate with the specifications imposed by many pipeline operators, which are typically ~10 µL/L. The methodology is in accordance with ASTM D7607 – 11 and offers a detection limit of 0.3 ppm v/v and a limit of quantification of 1 ppm v/v.
- A limit of detection 0.3 ppm v/v and a limit of quantification of 1.0 ppm v/v
- No interference from the presence of CO₂
- No interference from the presence of H₂S at concentrations ≤ 100 ppm v/v
- Method approved for BP CATS entrants
- LPG module available on request
- Quality Control standards used to verify calibration on site
- ATEX certification by Baseefa and Ɛx certification by ISSeP