Kousik Mandal
Punjab Agricultural University
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Featured researches published by Kousik Mandal.
Ecotoxicology and Environmental Safety | 2013
Kousik Mandal; Balwinder Singh; Monu Jariyal; V. K. Gupta
Fipronil, a phenyl pyrazole insecticide has been found to be effective for the control of various insect pests. Due to its higher persistence in soil bioremediation is a promising approach to degrade the pesticide from soil. Isolation and identification of soil microbes was conducted for bioremediation of fipronil contaminated soils. Soil samples collected from different sugarcane growing fields in Gurdaspur district with extensive use of pesticide history served as a source of pesticide degrading microbes. The microbe cultures were grown in Luria broth and maintained at 28°C. After that Dorns broth enrichment culture supplemented with fipronil was used and Bacillus thuringiensis were isolated. Clay loam soil samples were fortified with fipronil @ 0.50, 0.75, 1.00, 1.25 and 1.50mgkg(-1) along with 45×10(7) microbe cells. Each treatment was replicated thrice and from each fortified (insecticide+microbes) sample, 50g soil sample was taken at 7, 14, 28, 35, 42, 49 and 56 days after initiation of this experiment. Residues were not detected after 28, 35, 35, 35 and 42 days in soil samples after fortification with fipronil @ 0.50, 0.75, 1.00, 1.25 and 1.50mgkg(-1). Among metabolites, sulfide was found to be the main metabolite followed by sulfone and amide. Desulfinyl metabolite was not produced in any of the sample. Total fipronil residues were not found to follow the first order kinetics.
Bulletin of Environmental Contamination and Toxicology | 2010
Kousik Mandal; Balwinder Singh
Fifty samples of cauliflowers were collected from intensive vegetable growing areas in Punjab during 2007–08 to determine the magnitude and frequency of pesticidal contamination. The estimation of pesticide residues representing three major chemical groups i.e. organochlorine, organophosphorus and pyrethroids was done by using a multiresidue analytical methodology employing GC-ECD and GC-FTD systems with capillary columns and confirmed by GC–MS. Forty-two per cent samples were found to be contaminated with low but measurable amounts of residues. Among the three chemical groups, the organophosphates were dominant followed by organochlorines and pyrethroids. However, none of the samples were found to contain the residues of these insecticides above their respective maximum residue limits (MRL). On the basis of these limited observations, it is suggested that more extensive surveillance studies covering major cauliflower growing areas in the state be carried out to know the status of contamination, which may serve as a base for the national regulatory authorities to decide future policy of chemical use on vegetables.
Ecotoxicology and Environmental Safety | 2012
Urvashi Bhardwaj; Rajinder Kumar; Sarabjit Kaur; Sanjay Kumar Sahoo; Kousik Mandal; R. S. Battu; Balwinder Singh
Persistence of fipronil in cabbage was studied following three applications of Jump 80 WG at 75 and 150 g a.i. ha(-1) at 7 day interval. The average initial deposits of total fipronil (fipronil and its metabolites) were 1.226 and 2.704 mg kg(-1) on the heads following 3rd application of fipronil at single and double the dosages, respectively. Desulfinyl was found to be the main metabolite followed by sulfone and sulfide. Metabolite amide was not detected in cabbage samples. Half-life periods for fipronil were found to be 3.43 and 3.21 day at single and double the application rates, respectively. Risk assessment of fipronil to the consumers was calculated on the basis of per capita 80 g consumption of cabbage and comparing it to its ADI for an adult of 55 kg which was found to be less than its ADI on 10th day at both the dosages.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2012
Sanjay Kumar Sahoo; G. S. Chahil; Kousik Mandal; R. S. Battu; Balwinder Singh
Dissipation of β-cyfluthrin and imidacloprid in okra was studied following three applications of a combination formulation of Solomon 300 OD (β-cyfluthrin 9 % + imidacloprid 21 %) @ 60 and 120 g a.i. ha−1 at 7 days interval. Residues of β-cyfluthrin and imidacloprid in okra were estimated by gas liquid chromatography (GLC) and high performance liquid chromatography (HPLC), respectively. Residues of β-cyfluthrin were confirmed by gas chromatograph–mass spectrometry (GC-MS) and that of imidacloprid by high performance thin layer chromatography (HPTLC). Half-life periods for β-cyfluthrin were found to be 0.91 and 0.68 days whereas for imidacloprid these values were observed to be 0.85 and 0.96 days at single and double the application rates, respectively. Residues of β-cyfluthrin dissipated below its limit of quantification (LOQ) of 0.01 mg kg−1 after 3 and 5 days at single and double the application dosage, respectively. Similarly, residues of imidacloprid took 5 and 7 days to reach LOQ of 0.01 mg kg−1, at single and double dosages respectively. Soil samples collected after 15 days of the last application did not show the presence of β-cyfluthrin and imidacloprid at their detection limit of 0.01 mg kg−1.
Chemosphere | 2013
Kousik Mandal; Balwinder Singh
Samples of sandy loam and clay loam soils were collected from different geographical locations of Punjab. These soils were autoclaved at 120 °C at 15 psi for 15 min to destroy the microbes responsible for the degradation of pesticides before initiating the experiment. Each soil was fortified at three levels of fipronil i.e. 100, 200 and 400 mg kg(-1). The whole experiment was conducted at 25±2 °C under laboratory conditions. The residues of fipronil and its metabolites were quantified by Gas Liquid Chromatograph (GLC) and confirmed by Gas Liquid Chromatograph-Mass Spectrometry (GC-MS). The limit of quantification of fipronil and its metabolites was worked out to be 0.001 mg kg(-1). The residues of total fipronil in sandy loam and clay loam after 7 d of its application @ 100 mg kg(-1) were found to be 74.30 and 82.50 mg kg(-1), respectively. Fipronil residues were degraded to amide, sulfone and sulfide in both soils. Desulfinyl metabolite was not found in any of the sample. The persistence of fipronil was found to be more in clay loam soil than sandy loam soil. Total fipronil residues were not found to follow the first order kinetics. Half-life (T1/2) of total fipronil was observed to be 30.10, 33.44 and 33.44 d following application of fipronil @ 100, 200 and 400 mg kg(-1), respectively in sandy loam soil. In clay loam soil, half-life values were observed to be 37.63 d following application of fipronil at all three treatments.
Journal of Food Science | 2012
Balwinder Singh; Abhijit Kar; Kousik Mandal; Rajinder Kumar; Sanjay Kumar Sahoo
An easy, simple and efficient analytical method was standardized and validated for the estimation of residues of chlorantraniliprole in different vegetables comprising brinjal, cabbage, capsicum, cauliflower, okra, and tomato. QuEChERS method was used for the extraction and cleanup of chlorantraniliprole residues on these vegetables. Final clear extracts of ethyl acetate were concentrated under vacuum and reconstituted into high performance liquid chromatograph (HPLC) grade acetonitrile, and residues were estimated using HPLC equipped with PDA detector system, C(18) column and confirmed by liquid chromatograph mass spectrometer (LC-MS/MS), and high performance thin layer chromatograph (HPTLC). HPLC grade acetonitrile:water (80:20, v/v) was used as mobile phase @ 0.4 mL/min. Chlorantraniliprole presented distinct peak at retention time of 9.82 min. Consistent recoveries ranging from 85% to 96% for chlorantraniliprole were observed when samples were spiked at 0.10, 0.25, 0.50, and 1.00 mg/kg levels. The limit of quantification of this method was worked out to be 0.10 mg/kg.
Chemosphere | 2014
Kousik Mandal; Balwinder Singh; Monu Jariyal; V. K. Gupta
Persistence of fipronil, a new molecule in extensive use against various insect pests is causing serious problems to the environment. Bacillus firmus was isolated by selective enrichment from soil samples collected from sugar fields with known history of pesticide usage and evaluated for metabolization of fipronil in clay loam soil. Soil samples in 50 g aliquotes were fortified with fipronil @ 0.50-1.50 mg kg(-1) and inoculated with B. firmus cells (45×10(7) CFU mL(-1)) and incubated at 25 °C. Each sample in triplicates was drawn periodically up to 56 d and residual fipronil contents analyzed by gas liquid chromatograph. Fipronil residues were not detected after 35 d at lower doses of fipronil (@ 0.50, 0.75 and 1.00 mg kg(-1)). However, at higher doses (@ 1.25 and 1.50 mg kg(-1)) than this total metabolization of fipronil could be observed after 35 and 42 d, respectively. Thus whereas, B. firmus proved its potential in efficient metabolization of fipronil, the period required for the same was dose dependent. Amongst various metabolites of fipronil degradation, fipronil sulfide was found to be the main metabolite followed by fipronil sulfone and fipronil amide. Though, desulfinyl metabolite earlier reported as one of the main metabolite of fipronil degradation, the existence of the same was not detected in any of the treatment.
Ecotoxicology and Environmental Safety | 2013
Kousik Mandal; Balwinder Singh
The dissipation and persistence of fipronil in soil was studied following application of fipronil (Regent 0.3G) @ 75 and 300 g a.i. ha(-1). The limit of quantification for the analysis of fipronil and its metabolites by gas liquid chromatography was 0.001 mg kg(-1) for soil. The total residues of fipronil and its metabolites in soil after 7 days of its application @ 75 and 300 g a.i. ha(-1) were found to be 0.025 and 0.098 mg kg(-1), respectively. These residues could not be detected after 210 and 240 days following the application of fipronil at lower and higher dosages, respectively. In soil, fipronil was found to be the main constituent, followed by its metabolites sulfone, sulfide, amide and desulfinyl. The presence of sulfone in significant higher amount as compared to other metabolites in the soil clearly demonstrates that oxidation process plays a major role in the metabolism of fipronil. The half-life values (T(1/2)) of fipronil were calculated to be 50.2 and 43.0 days, respectively when applied @ 75 and 300 g a.i. ha(-1).
Journal of AOAC International | 2015
Ramandeep Kaur; Kousik Mandal; Rajinder Kumar; Balwinder Singh
An easy, simple, and efficient analytical method was validated for the determination of residues of fipronil and its metabolites in different vegetables comprising brinjal, cabbage, capsicum, cauliflower, okra, and tomato. The Quick, Easy, Cheap, Rugged and Safe method was used for the extraction and cleanup of fipronil and its metabolites on these vegetables. Final clear extracts of ethyl acetate were concentrated under vacuum and reconstituted into acetone, and residues were determined by GC/MS with an Rtx-5 capillary column. The retention times of desulfinyl, sulfide, fipronil, sulfone, and amide were 11.8, 15.8, 16.4, 19.7, and 24.1 min, respectively. The average recoveries obtained for fipronil and its metabolites at different spiking levels were determined to be above 85% in all samples. The repeatability and reproducibility in different matrixes ranged from 1.36 to 5.42 and 1.75 to 4.53%, respectively, for fipronil and its metabolites. The LOQ of this method was 0.01 mg/kg and LOD was 0.003 mg/kg.
Ecotoxicology and Environmental Safety | 2015
Monu Jariyal; V. K. Gupta; Vikas Jindal; Kousik Mandal
Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in soil. Three phorate utilizing bacterial species (Pseudomonas sp. strain Imbl 4.3, Pseudomonas sp. strain Imbl 5.1, Pseudomonas sp. strain Imbl 5.2) were isolated from field soils. Comparative phorate degradation analysis of these species in liquid cultures identified Pseudomonas sp. strain Imbl 5.1 to cause complete metabolization of phorate during seven days as compared to the other two species in 13 days. In soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil), Pseudomonas sp. strain Imbl 5.1 resulted in active metabolization of phorate by between 94.66% and 95.62% establishing the same to be a potent bacterium for significantly relieving soil from phorate residues. Metabolization of phorate to these phorate residues did not follow the first order kinetics. This study proves that Pseudomonas sp. strain Imbl 5.1 has huge potential for active bioremediation of phorate both in liquid cultures and agricultural soils.