Irani Mukherjee

Chromatographic techniques in the analysis of organochlorine pesticide residues.

The review briefly covers the chromatographic techniques used in the analysis of organochlorine pesticide residues. The organochlorines ranging from DDT, HCH, the cyclodiene group and the polychloroterpene group have been covered. It endeavours to examine the existing methodologies and techniques including residue extraction, clean-up, chromatographic procedures involved in clean-up and determination and quantification of organochlorine residues by gas liquid chromatography from different substrates like food commodities, crops, soil and water.

Environmental behaviour and translocation of imidacloprid in eggplant, cabbage and mustard

The recently registered insecticide, imidacloprid, was applied to three vegetable crops at 20 and 40 g AI ha−1. The persistence of the parent insecticide and its translocation, along with the quantification of the metabolites formed on these crops are presented. The parent insecticide dissipated with a half-life of 3–5 days and persisted longest on mustard leaves. The detectable limit of the HPLC method was 0.01 µg g−1. The metabolites 1-(6-chloropyridin-3-yl-methyl)imidazolidin-2-one and 6-chloronicotinic acid were found to be translocated by day 10 in eggplant, cabbage leaves and mustard leaves but not in cabbage curd. The MRL of imidacloprid is not documented by the FAO/WHO on these crops and comparison of the MPI with the TMRC, calculated on the residue data generated in this study, establishes the safety of the schedule. © 2000 Society of Chemical Industry

Organochlorine insecticide residues in drinking and ground water in and around Delhi.

A multiresidue method was developed for the estimation of 15organochlorine pesticides in water. 50 samples of drinking watersupplied by the Municipal Corporation to the residential areasof Delhi and 20 ground water samples from nearby villages usedfor irrigation were monitored for the presence of organochlorineinsecticides by the method developed. Although, organochlorinepesticides were detected in the ground water and irrigationwater samples, the levels of pesticides were below the MaximumContaminant Level as prescribed by WHO. No organochlorineinsecticides were detected in any of the drinking water samples.

Degradation of beta‐endosulfan by Aspergillus Niger

Abstract The organochlorine insecticide endosulfan is a mixture of two stereoisomers, alpha and beta. The degradation of the more persistent beta isomer was shown using the soil microorganism Aspergillus niger. The relatively rapid rate of degradation of beta‐endosulfan as compared to control, formation of endosulfan diol and absence of formation of the toxic metabolite endosulfan sulfate suggest the possibility of developing a non‐chemical method for degrading endosulfan.

Pesticides Residues in Vegetables in and around Delhi

This article presents the development of a multiresidue method forthe estimation of 30 insecticides, 15 organochlorineinsecticides and 6 organophosphorus insecticides, 9 syntheticpyrethriods and 2 herbicides and their quantificationin vegetables. The monitoring study indicates that though allthe vegetable samples were contaminated with pesticides, only31% of the samples contained pesticides above the prescribedtolerance limit.

Determination of Pesticide Residues in Integrated Pest Management and Nonintegrated Pest Management Samples of Apple (Malus pumila Mill.)

Studies were undertaken to analyze the residues of commonly used pesticides viz. chlorpyrifos, endosulfan, dicofol, cypermethrin, fenvalerate, propargite, malathion, phorate, carbendazim, carbosulfan, thiamethoxam, and mancozeb in apple of integrated pest management (IPM) and non-IPM samples collected from the IPM and non-IPM fields of Shimla. We also present a method for the determination of these pesticides in apple samples. Residues of chlorpyrifos, endosulfan, dicofol, cypermethrin, fenvalerate, and propargite were analyzed by gas chromatography, while residues of carbendazim, carbosulfan, and thiamethoxam were analyzed by high-performance liquid chromatography. Residues of mancozeb were determined by a colorimetric method. Recoveries of all of the pesticides ranged from 61.30 to 95.46% at 0.1, 0.2, and 1.0 microg g(-1) levels of fortification with relative standard deviations ranging between 0.8 and 8.7. Apples from IPM and non-IPM orchards were analyzed for these pesticides using a developed method. Except for carbendazim and chlorpyrifos, the residues of all of the pesticides analyzed were below detectable limits. Although residues of carbendazim and chlorpyrifos were below the prescribed limits of maximum residue levels in both IPM and non-IPM orchards, residues were lower in apples from IPM orchards.

Degradation of chlorpyrifos by two soil fungi Aspergillus niger and trichoderma viride

Two soil fungi, namely Aspergillus niger and Trichoderma viride were evaluated for the degradation of chlorpyrifos. T. viride has been found to be more active, 95.7% of chlorpyrifos degraded in the presence of T. viride as compared to 72.3% in A. niger by day—14. The toxic metabolite of chlorpyrifos, 3, 5, 6‐trichloropyridinol was not detected during the 14‐day incubation period.

HCH, endosulfan, and fluvalinate residue behavior in pigeonpea (Cajanus cajan L. Millsp).

Pigeonpea (Cajanus cajan L. Millsp) is one of the major pulse crop of India. The loss of pigeonpea crop due to pod and foliage pests is significant, the major pests being pod fly, hairy caterpillar, aphids, white fly, plume moth borer, leaf caterpillar and jassids. It is imperative to save every grain by chemical control methods but these toxicants should not leave unusually high residues on the edible parts. In this paper the authors report the residue behavior of three different insecticides namely, hexachlorocyclohexane, endosulfan and fluvalinate on this crop.

Determination of pesticide residues in IPM and non-IPM samples of mango (Mangifera indica)

Studies were conducted to analyze the residue of commonly used pesticides viz. methyl parathion, chloropyrifos, endosulfan, cypermethrin, fenvalerate, carbendazim, imidacloprid and carbaryl in mango, Dashehari variety, integrated pest management (IPM) and non-IPM samples were collected from the IPM and non-IPM orchards, Lucknow, India. We also present a method for the simultaneous determination of these pesticides in mango samples. Residues of methyl parathion, chloropyriphos, endosulfan, cypermethrin, fenvalerate were extracted from the samples with acetone: cyclohexane: ethyl acetate in the ratio 2:1:1 followed by cleanup using neutral alumina. Analysis was performed by gas chromatography-electron capture detector (GC-ECD) with a megabore column (OV-1). Residues of carbendazim, imidacloprid and carbaryl were extracted with acetone and after cleanup, analysis was performed by high performance liquid chromatography (HPLC) using photo diode array (PDA) detector. Recoveries of all the pesticides ranged between 72.7 – 110.6%, at 0.1 and 1.0 μg g− 1 level of fortification. The residues detected in non-IPM samples of mango were found to be below the prescribed limits of maximum residue limit (MRL) while IPM samples were free from pesticide residues.

Degradation of tricyclazole: Effect of moisture, soil type, elevated carbon dioxide and Blue Green Algae (BGA)

Pesticide persistence and degradation in soil are influenced by factors like soil characteristics, light, moisture etc. Persistence of tricyclazole was studied under different soil moisture regimes viz., dry, field capacity and submerged in two different soil types viz., Inceptisol and Ultisol from Delhi and Karnataka, respectively. Tricyclazole dissipated faster in submerged (t1/2 160.22-177.05d) followed by field capacity (t1/2 167.17-188.07d) and dry (t1/2 300.91-334.35d) in both the soil types. Half-life of tricyclazole in Delhi field capacity soil amended with Blue Green Algae (BGA), was 150.5d as compared to 167.1d in unamended soil. In Karnataka soil amended with BGA the half-lives were 177.0d compared to 188.0d in unamended soil, indicating that BGA amendment enhanced the rate of dissipation of in both the selected soils. Tricyclazole was found to be stable in water over a pH range of 3-9, the half life in paddy field was 60.20d and 5.47d in paddy soil and paddy water, respectively. Statistical analysis and Duncans Multiple Range Test (DMRT) revealed significant effect of moisture regime, organic matter and atmospheric CO2 level on dissipation of tricyclazole from soil and pH of water (at 95% confidence level p<0.0001).