Around the world and across the board, prices are rising. As we battle with the realities of post-COVID supply chain issues and international wars, companies struggle to keep their own costs low. One unscrupulous way to do this is to use lower-quality ingredients. The average customer may not be able to notice the difference between a genuine or artificial citrus essential oil, for example, but being able to determine the constituents of the oil is vital for determining its quality and safety, as most citrus essential oil uses involve direct contact with humans.
Gas chromatography-mass spectrometry (GC-MS) is the best way for a qualitative characterization of the volatile fraction of essential oils, but the methods typically used for this purpose use long GC capillary columns and slow oven ramp rates for analysis times that can run longer than one hour. A typical GC-MS method also uses helium as a carrier gas.
A better way to save money is to work smarter instead of cutting quality. Helium is an expensive consumable, but the right GC-MS can be configured to use hydrogen instead. An instrument such as the Pegasus® BT, with its open ion source design, is ideal for analysis using hydrogen as a carrier gas. Of course, with any change, there are always concerns about maintaining the quality of results. LECO recently did a study using citrus essential oil, transferring a typical helium method to an optimized hydrogen method, to determine if there is actually a loss of resolution. After five method transfer steps, the chromatographic resolution for the initial helium method was calculated at 2.2, while the final hydrogen method resulted in a chromatographic resolution of 2.1, a decrease of only about 10%.
The small decrease in resolution was more than made up for in the drastic decrease in time. As any employer could tell you, staff wages tend to make up the largest percent of any operating budget. The less time someone needs to spend on running an analysis, the more the cost savings will quickly add up. In the initial helium run, nootkatone, the last eluting compound of interest in the sample tested, eluted at 18.89 minutes. In the optimized hydrogen run, nootkatone eluted at 4.36 minutes. This is an analysis time reduction of approximately 77%. With the hydrogen method, four analyses could be run in the same amount of time as one helium-based analysis. There was no significant drop in result quality with the drastic decrease of time. The ChromaTOF® brand software‘s Non-Target Deconvolution® algorithm and automated RI calculation were able to identify as many analytes as possible, with an average library score of 860/1000.
Learn more about the methodology used to get these results with a Pegasus BT and a citrus essential oil mix.
