Title : Monitoring ethylene oxide and 2-chloroethanol residues in food: A simplified QuEChERS-based GC-MS/MS method for routine analysis
Abstract:
Ethylene oxide (EtO) is a pesticide whose use in food has been banned in the European Union since 1991. However, recent contamination incidents have raised significant concerns for human health. In particular, high levels of EtO were detected in sesame seeds from India in September 2020, leading to an increase in contamination notifications under the Rapid Alert System for Food and Feed (RASFF) [1]. Despite regulatory interventions, EtO contamination has continued to be found in a wide range of food categories, including spices (e.g., ginger, caraway, white pepper), herbal teas (e.g., chamomile), food supplements, and additives such as xanthan gum [2]. In this context, the present study proposes a rapid and simplified QuEChERS-based method for the determination of ethylene oxide in various food matrices, based on its conversion into the proxy compound 2-chloroethanol (2-CE), followed by quantification using isotope dilution coupled with gas chromatography–tandem mass spectrometry (GC-MS/MS). Analyses were carried out using an Agilent 8890 GC system equipped with an Agilent 7010C triple quadrupole mass spectrometer and an Agilent 7693A autosampler. In contrast to the columns typically used in similar studies reported in the literature, this work employed an Agilent HP-5ms Ultra Inert column (30 m × 250 μm × 0.25 μm), routinely used in our laboratory for multi-residue analyses, to achieve chromatographic separation.
The method covers a range of food matrices and was validated in accordance with the SANTE/11312/2021 guidelines by evaluating linearity, limit of quantification (LOQ), selectivity, precision (under repeatability conditions), and accuracy (expressed as percent recovery). A total of 47 samples, mainly imported from India, were collected and analyzed as part of official control activities conducted in the Lazio region (Italy). The sample set included spices, dietary supplements, okra, oilseeds and pharmaceutical products. Notably, 2-chloroethanol was detected in four samples, and in one case, the sum of ethylene oxide and its metabolite exceeded the maximum residue limit (MRL) established by European regulations [3]. These findings further demonstrate the ongoing risk posed by ethylene oxide contamination and underscore the urgent need for continuous monitoring, robust analytical protocols, and risk-based regulatory action to ensure consumer safety.
