Determination of ethylene chlorohydrin as marker of spices fumigation with ethylene oxide

Ethylene oxide (EO) is a gas used to sterilize spices, drugs, packaging materials, medical devices, polyester fibers, plastics and synthetic rubber. When the aeration step foreseen for spices is not properly carried out, residues of EO and its derivative ethylene chlorohydrin (ECH), produced by reaction with chlorine ions always present in the matrix, can be found in these products.In this way, the reactivity of EO with chlorides in spices provides a suitable marker to confirm the use of EO for fumigation. The ECH derived from spontaneous transformation during the storage and forcibly obtained during the first step of the extraction can be evaluated in spices by a simple GC/MS analytical method, without derivatization.It has been proven that the EO molecule is carcinogenic for humans; it has been classified as a category 1 carcinogen by the International Agency for Research on Cancer (IARC): ECH, as EO, is a mutagenic substance.This paper shows the results concerning 25 pepper samples purchased on the Italian market.The limit of detection for ECH was assumed to be 20 μg/kg (LOD) and was calculated by spiking a matrix pepper that had not been treated with EO. The limit of quantitation was assumed to be 100 μg/kg (LOQ), i.e. 5 times LOD. The reliability of the method was verified by recovery and repeatability tests. Recovery average values are 60–70% (CV%=9.6–5.5) for the concentration range 100–500 μg/kg.Only 56% of pepper samples analyzed did not contain ECH at detectable levels, and only 24% of pepper samples contained ECH at levels lower than LOQ. Three samples had a content ranging between 0.2 and 3.3 mg/kg and two samples showed a content of ECH higher than 5 mg/kg.