3-Fold Faster Polybrominated Diphenyl Ether (PBDE) Short Column Method
- Increase sample throughput with 3-fold faster analysis times.
- Proprietary deactivation reduces thermal breakdown, giving high BDE-209 response and excellent peak symmetry for all PBDE congeners.
- Meets all method criteria and reliably separates BDE-49 and BDE-71.
Polybrominated diphenyl ethers (PBDEs) are highly effective flame retardants and have been instrumental in protecting both lives and property. Despite these benefits, many PBDEs have been banned or are being phased out because of concern surrounding negative health effects related to the ubiquitous presence of PBDEs in humans and the environment. While exposure mechanisms and pathways are not completely understood, bioaccumulation of these lipophilic compounds is a concern as PBDEs have been linked to toxic, neurological, and reproductive problems. Due to a growing need to monitor PBDEs in the environment, rapid and accurate methods are increasingly in demand.
EPA Method 1614 is commonly used to analyze PBDEs in water, soil, sediment, and tissues. This method presents a considerable challenge to the analytical column due to the large number of compounds, resolution and peak symmetry requirements, and the active nature of BDE-209. The original draft method specified a 30 meter column; however, due to a better understanding of the challenges presented by the method compounds and performance metrics, shorter columns are now acceptable. Short column methodology presents an important opportunity for increasing sample throughput, but requires an analytical column with high efficiency to separate critical pairs and sufficient sensitivity for active target compounds.
Restek has developed a new 15m Rtx-1614 column specifically for the analysis of PBDEs and optimized the GC conditions to obtain fast analysis times. As shown in Figure 1, compounds are separated in under 20 minutes—3 times faster than typical analyses on traditional 30m columns. All method criteria were easily met, including the separation of BDE-49 and BDE-71. Resolution of these compounds was 8% based on valley height relative to the height of the shortest peak, which is well within the EPA 1614 requirement of less than 40%.
In developing the Rtx-1614 column, the deactivation was optimized to give a high response for BDE-209, which is the most challenging compound in the method. BDE-209 readily breaks down due to heat and active sites in both the injection port and column. On-column breakdown of BDE-209 is often observed as peak fronting, but the deactivation used to manufacture the Rtx-1614 column virtually eliminates this problem. The high inertness of this column also results in outstanding peak symmetry for all PBDEs, including BDE-99 (as determined by EPA method 1614 tailing factor). The high response and excellent symmetry for BDE-209 and other PBDEs observed on the Rtx-1614 column improves overall accuracy in sample reporting, and shortened analysis time allows more samples to be run per hour.
In conclusion, the new 15m Rtx-1614 column is an excellent column for analyzing polybrominated diphenyl ethers. Under the conditions shown, all chromatographic method criteria can be met in just 20 minutes, compared to 60 minute run times for typical longer column methods. Speeding up analysis times by a factor of 3 using the 15m