BOC Uses Servomex Gas Purity Analyser to Validate New European Pharmacopoeia Method
Share:
Within medicine, helium, mixed with varying concentrations of oxygen, is increasingly being used to treat the symptoms of respiratory ailments to make life more comfortable for the patients. To date there has been no monograph for helium in the European Pharmacopoeia (EP). Working with the EP, BOC, the world's largest supplier of helium, were responsible for the validation of the analytical methods proposed for the new monograph. The methods were to be validated in line with the ICH standards (the ICH being the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use).
Helium is extracted from natural gas in certain areas of the world e.g. Poland and the USA. It is present at a concentration of around one per cent. As methane is the main constituent of natural gas, monitoring the level of trace methane (CH4) in helium gives a good indication of the correct operation of the helium purification process, as methane will be the most prominent contaminant. Although it is not thought that low levels of methane in helium have a detrimental affect on patients, the EP monograph states an upper limit of 50 ppm.
As part of the package of work, BOC had to complete a validation trial on a gas analyser capable of measuring trace methane in helium. Because the company had previously used Servomex gas analysers successfully for various applications, BOC requested a loan unit from Servomex. This was delivered promptly, allowing BOC to complete the validation trial and confirm the specification within a tight two-week deadline.
Servomex provided a 4100 gas purity analyser with a 0-50/500 ppm methane measurement range and an intrinsic error (accuracy) of better than one per cent of reading or 0.5 ppm(v) methane, whichever is greater. This exceptional performance is largely due to the analyser's use of an infrared gas measurement technique incorporating gas filter correlation (GFC). Not only does this deliver high accuracy even at low concentrations of the target gas, but it also ensures that the measurements are virtually immune to cross-interference.
Faye South, an analyst at BOC, comments: "We were already using a similar Servomex instrument for high-accuracy oxygen measurements, so it was an obvious choice for us to use a Servomex analyser for this validation trial. The instrument was supplied on loan very quickly and it performed faultlessly. I have always found Servomex gas analysers to be straightforward to use, and the 4100 was no exception. Indeed, it was very fortunate that we had access to this instrument, as it enabled us to validate the method so that the European Pharmacopoeia will accommodate infrared analysers of this type."
Furthermore, looking ahead to BOC's possible use of the Servomex 4100 in a production environment, Faye South adds: "Beyond the EP requirements, areas of concern to us as an end user would be response time and calibration drift. Needless to say, the Servomex 4100 appears to perform extremely well in both respects, allowing us to identify any problems with the production process very rapidly, while also keeping the operating costs for the analyser as low as possible."
During the validation trial, the Servomex 4100 gas analyser was tested against the ICH Q2 guidelines that cover, for example, linearity, accuracy, precision, detection limit, quanititation limit and robustness.
As a result of the validation trial carried out by BOC, the new EP will specify the monitoring of trace methane in helium using infrared gas analysis. BOC will most likely order multiple Servomex 4100 gas purity analysers for on-line analysis in its medical helium facilities, and other European producers of medical helium could well do the same. Servomex can fully support end users throughout Europe or, indeed, anywhere in the world.
For more information about the Servomex 4100 gas analyser and to discuss particular applications, please contact Servomex on +44 1892 652181 or e-mail info@servomex.com.
