Improved GC/ECNI-MS sensitivity of decabromodiphenyl ether determination on 30 m columns by increasing the carrier gas flow after a modified gel permeation chromatographic cleanup protocol employing cyclohexane/ethyl acetate as eluent

BDE-209 is the predominant constituent of the commercial mixture decabromodiphenyl ether which is used as brominated flame retardant (BFR). Owing to difficulties associated with the high mass (thermal instability and low vapour pressure), short GC columns (≤15 m) have been suggested for its analysis while longer columns (30–50 m) are suggested for other polybrominated diphenyl ether (PBDE) congeners. To overcome this considerable expenditure in the analysis of PBDEs, we aimed at increasing the sensitivity of BDE-209 analysis by gas chromatography coupled with electron-capture negative ion mass spectrometry (GC/ECNI-MS) on a 30 m column. The chromatographic performance of BDE-209 on the 30 m GC column was improved by increasing the carrier gas flow from initially 1.2 mL min−1 to 5 or 10 mL min−1 after the last octabromo diphenyl ether (Br8DE) congener was eluted. With this high carrier gas flow, the column residence time of BDE-209 was shortened by ∼25%, the peak height was increased and, consequently, the...