In-Source and Collision Induced Dissociation of Herbicides: A Mass Spectrometry Study
Disciplines
Analytical Chemistry
Abstract (300 words maximum)
The persistent pesticides and their degraded products can be spread around the globe due to their physiochemical properties. Pesticides can generate secondary products through various gas phase transport and transformation processes. These secondary products may have adverse effects compared to the primary pesticides. Although various investigations are being conducted to detect the degradation products of pesticides in soil and water, few studies are focused on the gas phase degradation. The purpose of this study is to detect the gas phase degradation products of various pesticides using in-source and collision induced dissociation techniques incorporated in mass spectrometer. In this study, we have studies the gas phase fragmentation of three herbicides. In low in-source voltage of 50V, N-(3,4-Dichlorophenyl)propenamide (propanil) was fragmented near the amide bond. However, at high in-source voltage of 100 V, chlorine radical was formed along with amide cleavage. Less fragment ions are generated when collision induced dissociation energy was applied to propanil. In case of N′-(3,4-Dichlorophenyl)-N,N-dimethylurea, known as Diuron which is used as algicide and herbicides, three distinct fragments products were detected where CH3 and Cl radical were formed along with the C-N bond cleavage. However, for glyphosate herbicides, no in-source fragment product was noticed. The collision induced dissociation showed the breaking of C-P bond generating a fragment at 88.0 m/z corresponds to C3H6NO2 ion. This study shows that propanil and Diuron herbicides are sensitive to be fragmentated at atmospheric condition whereas glyphosate required to be collided with high energy gases.
Academic department under which the project should be listed
Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
In-Source and Collision Induced Dissociation of Herbicides: A Mass Spectrometry Study
The persistent pesticides and their degraded products can be spread around the globe due to their physiochemical properties. Pesticides can generate secondary products through various gas phase transport and transformation processes. These secondary products may have adverse effects compared to the primary pesticides. Although various investigations are being conducted to detect the degradation products of pesticides in soil and water, few studies are focused on the gas phase degradation. The purpose of this study is to detect the gas phase degradation products of various pesticides using in-source and collision induced dissociation techniques incorporated in mass spectrometer. In this study, we have studies the gas phase fragmentation of three herbicides. In low in-source voltage of 50V, N-(3,4-Dichlorophenyl)propenamide (propanil) was fragmented near the amide bond. However, at high in-source voltage of 100 V, chlorine radical was formed along with amide cleavage. Less fragment ions are generated when collision induced dissociation energy was applied to propanil. In case of N′-(3,4-Dichlorophenyl)-N,N-dimethylurea, known as Diuron which is used as algicide and herbicides, three distinct fragments products were detected where CH3 and Cl radical were formed along with the C-N bond cleavage. However, for glyphosate herbicides, no in-source fragment product was noticed. The collision induced dissociation showed the breaking of C-P bond generating a fragment at 88.0 m/z corresponds to C3H6NO2 ion. This study shows that propanil and Diuron herbicides are sensitive to be fragmentated at atmospheric condition whereas glyphosate required to be collided with high energy gases.