Detection and mass spectral characterization of carbofuran and its degradation product

Abstract

Carbofuran is an N-methyl carbamate pesticide that is extensively used to control insects and nematodes on a range of farming crops because of its wide-ranging biological activity & relatively low persistence when compared to other pesticides. It is highly toxic to birds, mammals, fish and wildlife due to its anticholinesterase activity. In humans, Carbofuran is associated with endocrine disrupting activity, reproductive disorders, cytotoxic and genotoxic abnormalities. In biological and environmental conditions Carbofuran tend to undergo degradation. The screening, identification and characterization of the Carbofuran and its degradation product in biological samples are an important task in the area of forensic toxicology. In a case study Carbofuran and its degradation product Carbofuran phenol were detected and identified by Gas Chromatography Mass Spectrometry. The present study deals with the successful detection & characterization of the Carbofuran and its degradation product under positive ion Electron Ionization (EI) mass spectrometry. The EI mass spectra of the Carbofuran and its degradation product showed the stable molecular ion [M+•] peaks in addition to the other diagnostic fragment ions that enable unambiguous identification of Carbofuran and its Carbofuran phenol. The general fragmentation patterns of these two compounds are discussed in detail. Carbofuran showed an ion at m/z 164 as the base peak corresponds to loss of Methylisocyanato group (CH3NCO) from the [M+•] ion, which was formed by the Mclafferty rearrangement. Carbofuran phenol showed a more stable Molecular ion [M+•] peak compared to Carbofuran and showed a major peak at m/z 149 corresponds to the loss of methyl group from the [M+•] ion. The detection and identification of these compounds will be an invaluable support during investigation and in conviction of criminal cases in courts of law in Carbofuran poisoning cases.