A New Headspace Gas Chromatography Method for Determination of Ethylene Oxide and Dioxane in Polyethylene Glycols

In this paper, a new headspace gas chromatography (HSGC) method has been developed for the determination of ethylene oxide (EO) and 1,4-Dioxane (Dioxane) in bulk lots of polyethylene glycols (PEG). PEG samples are dissolved in dimethyl sulfoxide, heated in a headspace oven maintained at 90°C for 10 min and then injected into the GC system for analysis. Analytes are separated through a thermal gradient elution from 36 to 240°C on an Agilent DB-624 column (60 m × 0.53 mm diameter, film thickness 3.00 μm). The carrier gas is helium and detector is flame ionization detector. Total run time of the new HSGC method is about 18 min. In the new HSGC method, other common residual solvents present in PEGs such as methanol (MeOH), methyl formate (MF) and acetyl aldehyde (Acetal) are also sufficiently separated from EO and Dioxane peaks. In the HSGC methods prescribed in USP monograph <228> and EP monograph <2.4.25>, EO co-elutes with MF. The new HSGC method was successfully validated according to current ICH/VICH guidelines and was found to be specific, linear, accurate, precise, robust and sensitive. This HSGC method is fast and quality control (QC) friendly and suitable for routine analysis for the determination of EO and Dioxane in bulk batches of PEGs in QC laboratories.