Bulk carbon dioxide (CO2) is used in industries as diverse as healthcare, beverage preparation, and semiconductor manufacturing. However, trace impurities in bulk carbon dioxide can pose both safety and taint risks in beverage and healthcare applications. Reduced product yield can occur for semiconductor manufacturers.
Recently, we developed a method for analysis of bulk CO2 for the food and beverage industry. Selected Ion Flow Tube Mass Spectrometry – SIFT-MS provides direct, simple, and rapid analysis for a diverse range of trace impurities to low part-per-billion concentrations:
- Aromatic hydrocarbons: benzene, toluene, and ethylbenzene
- Short-chain aliphatic hydrocarbons: ethane, ethene, propane, and propene
- Sulfur compounds: hydrogen sulfide, carbon disulfide, methyl mercaptan, and carbonyl sulfide
- Oxygenates: methanol, ethanol, and acetaldehyde
- NOx: NO, and NO2
- Other: ammonia.
This application again illustrates the benefit of SIFT-MS – detection of a chemically diverse species in one analysis. And by using negatively charged reagent ions, sulfur dioxide (SO2) can also be added.
During method development, the initial customer compared SIFT-MS results with those obtained using their standard gas chromatography (GC) method. Initially there appeared to be a discrepancy for benzene: SIFT-MS reported only 1 ppb, whereas the GC reported 20 ppb. After troubleshooting the two instruments – which included preparing and analyzing a benzene standard in CO2 – SIFT-MS was vindicated! The retention time in the GC had shifted because of the CO2 matrix, causing benzene to incorrectly report 20 times higher in the GC method.
To learn more about SIFT-MS and its applications for analysis of carbon dioxide and other bulk gases, browse our website or email email@example.com.