Confirmation of ethylene dibromide in fruits and grains by mass spectrometry

Abstract

Gas chromatography/mass spectrometry techniques uslng chemlcal lonlratlon and electron Impact have been employed to conflrm the presence of ethylene dlbromlde In frults and gralns determlned by electron capture detection gas chromatrography. Interferences from both the solvent and coextractables have been mlnlmlzed to permlt a determlnatlon uslng only two Ions detected In the correct experlmental lntenslty ratlo belonging to the monobromoethylene carbonlum fragment Ion. A complementary measurement under negative Ion methane chemlcal lonlratlon has determlned the bromide Ion to be present.

Derivatization of ethylene dibromide with silica-supported silver picrate for improved high-performance liquid chromatographic detection

“…They should be converted into primary amines by an additional procedure such as oxidation prior to derivatization (6,7). For the simultaneous determination of both primary and secondary amines, various types of reagents have been developed such as halogenosulfonate (8)(9)(10), formate (11,12), nitroaryl halide (13-15), sulfonic acid (16), isocyanate (17), isothiocyanate (18,19), etc.…”

“…Since isocyanate and isothiocyanate reagents readily react with amines under the mild conditions to give stable urea or thiourea derivatives without forming byproducts, various labeling reagents (17)(18)(19)(20)(21)(22)(23) of this type have been developed and applied to amino acid analyses, Edmann degradation (18)(19)(20)(21), or chiral derivatization (22)(23)(24). However, these compounds were moisture-sensitive lachrymators, and their synthesis has required phosgen or thiophosgen.…”

“…Additional studies have confirmed EDB's toxic effects (3, 4), and permissible occupational exposure levels have been set (5). EDB has been detected in ambient air (2, 6-13), water (12,14,15), foods (7,13,(16)(17)(18)(19)(20)(21), soil (22, 23), and biological samples (12,15,23). The ability to constantly monitor EDB is very important, and several analytical techniques to detect and/or confirm the presence of EDB are needed.…”

Automated headspace GC‐MS analysis of ethylene dibromide fumigant residues in fresh fruits

“…For citrus fruits, benzene/water azeotropic distillation has been proposed (King et al 1980) with slight variations on the procedure being the use of a Dean and Stark apparatus for the distillative extraction (Sekita et al 1983) and a further clean-up of the distillate by passing through a column of fuming sulphuric acid absorbed onto silica gel (Iwata et al 1983) to achieve limits of quantitation by ECD of around 5//g/kg. Confirmation of EDB-positive samples from preliminary ECD screening has been reported by GC-MS using both chemical ionization and electron impact modes (Cairns et al 1984).…”

Polarographic reduction and determination of 1,2-dibromoethane in aqueous solutions

“…Though retention times may be reduced, it is difficult to perform a sufficiently rapid analysis with good resolution from the solvent front (2). The purity of solvent seems to be critical as the impurity peaks are close to EDB retention times (10) and coextractables may interfere with the confirmation by mass spectrometry (8).…”