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.     

Persistent organochlorine pesticides in internal organs of coypu,Myocastor coypus

A highly selective and sensitive method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) to identify and quantify persistent organochlorine pesticides, (18 compounds including primary compounds and metabolites), in animal internal organs (kidneys, liver, and brain) has been developed. Tandem mass spectrometric conditions were individually optimized for each target compound in Multiple Reaction Monitoring (MRM) mode to obtain maximum sensitivity. Prior to instrumental analysis, a sample preparation method based on matrix solid phase dispersion (MSPD) followed by acidic digestion with sulfuric acid to reduce matrix co-extractives was employed. Analyses of real samples were carried out on coypus (Myocastor coypus) from the autumn slaughter of 19 animals. In the analyzed samples, three of the target compounds, namely DDE-pp′ (DDT metabolite), HCB and lindane, were detected. Their concentration levels fell in the ranges of 0.003–0.007, 0.003–0.025, and 0.003–0.021 mg kg^?1 (0.005, 0.010, and 0.010 mg kg^?1 on average) in the case of DDE-pp′, HCB and lindane, respectively. Although low quantities of organochlorine pesticides do not pose an immediate danger to consumers' health, they should be of public health concern considering long-term, low-dose exposure.     

Application of chemometric analysis based on physicochemical and chromatographic data for the differentiation origin of plant protection products containing chlorpyrifos

The aim of this study was to investigate the similarities and dissimilarities between the pesticide samples in form of emulsifiable concentrates (EC) formulation containing chlorpyrifos as active ingredient coming from different sources (i.e., shops and wholesales) and also belonging to various series. The results obtained by the Headspace Gas Chromatography–Mass Spectrometry method and also some selected physicochemical properties of examined pesticides including pH, density, stability, active ingredient and water content in pesticides tested were compared using two chemometric methods. Applicability of simple cluster analysis and also principal component analysis of obtained data in differentiation of examined plant protection products coming from different sources was confirmed. It would be advantageous in the routine control of originality and also in the detection of counterfeit pesticides, respectively, among commercially available pesticides containing chlorpyrifos as an active ingredient.     

Novel pipette-tip graphene/poly (vinyl alcohol) cryogel composite extractor for the analysis of carbofuran and carbaryl in water

A novel pipette-tip extractor of a graphene/poly (vinyl alcohol) cryogel (graphene/PVA) composite sorbent was prepared to preconcentrate carbamate pesticides in environmental water samples before analysis with a gas chromatograph-flame ionization detector (GC-FID). This novel pipette-tip extractor with the graphene/PVA sorbent exhibited a high porosity when observed through a scanning electron micrograph (SEM). Under optimal conditions, using only 1.0 mL of sample and 0.75 mL of eluting solvent, the developed method provided a wide linear range of 10–700 ng mL^?1 and 10–500 ng mL^?1 with limit of detection (LOD) of 6.40 ± 0.18 and 9.17 ± 0.34 ng mL^?1 for carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) and carbaryl (1-naphthyl methylcarbamate), respectively. The pipette-tip extractor provided high extraction efficiency with high accuracy indicated, by good recoveries in the range of 74.5 ± 4.8% to 119.7 ± 1.6% and 76 ± 15% to 114 ± 19% for carbofuran and carbaryl, respectively. In addition, the fabrication procedure showed a good pipette-tip extractor-to-pipette-tip extractor reproducibility with a relative standard deviation of 1.3–9.8% (n = 5). When the developed pipette-tip extractor was applied for the extraction of carbofuran and carbaryl in surface water samples near vegetable plantation areas, 25.9 ± 8.2 ng mL^?1 of carbofuran was found, and carbaryl was also detected in concentrations that ranged from 45.0 ± 4.0 to 191 ± 13 ng mL^?1.     

Comparison of two sample preparation methods for analysis of organochlorine pesticides residues in fish muscle

The aim of this study was to compare recoveries of organochlorine pesticides (heptachlor, α-HCH, β-HCH, γ-HCH, op′-DDD, pp′-DDD, pp′-DDE, op′-DDT, pp′-DDT) from fish muscle dried by two alternative methods: (i) grinding with anhydrous sodium sulphate and (ii) freeze drying. Pesticide residues content was determined by gas chromatography-mass spectrometry (GS-MS) method. For four pesticides (γ-HCH, α-HCH, heptachlor and pp;-DDD) in four of five fish species, higher recoveries were obtained from the freeze-dried samples. For five remaining pesticides, correlations between fish species and drying method were not found. The results of this study do not clearly indicate which drying method caused lower losses of analytes. Recoveries from the freeze-dried samples ranged from 69.9 to 117.6 %, while recoveries from the samples ground with sodium sulphate varied from 64.4 to 126.7 %. Either of the methods gave satisfactory recoveries and they both can be used interchangeably.     

Assessment of daily intake of organochlorine pesticides from milk in different regions of Poland

The common occurrence of organochlorine compounds in the environment, food and human tissues may constitute a serious threat to human health. The method of gas chromatography-mass spectroscopy was used to determine the content of pesticides in 15 samples of raw cow's milk from different regions of Poland. The results revealed high levels of p,p′-DDE, p,p′-DDT, heptachlor and aldrin. The studied milk contained lindane in average concentrations within the maximum limits. Although in 20% of all samples tested, the concentration of lindane exceeded permissible limits, while in 15% of samples the content of Σ DDT was too high. But the average daily consumption of milk containing organochlorine pesticides poses no direct threat to human health, because daily intake (DI) for all compounds were below the acceptable daily intake (ADI). Attention should be paid to the exposure of consumers to pesticide residues from other dairy foods.     

Validation of a multiclass multiresidue method and monitoring results for 210 pesticides in fruits and vegetables by gas chromatography-triple quadrupole mass spectrometry

A rapid, sensitive, accurate and reliable multiresidue method for the identification and quantification of 210 relevant pesticides in four representative fruit and vegetable commodities (tomato, potato, spring onion and orange) has been developed and validated by gas chromatography in tandem with triple quadrupole mass spectrometry. The method has been fully validated and applied to 292 samples from different countries. Prior to instrumental analysis, an extraction procedure based on a sample extraction of multiclass analytes, using the ethyl acetate method was employed. Mass spectrometric conditions were individually optimized for each compound in the selected reaction monitoring (SRM) mode to achieve maximum sensitivity. The pesticides were separated in less than 25 min. This was followed by an exhaustive control of the retention times. The Retention Time Locking Method was applied, working at a constant pressure throughout the analysis. System maintenance was reduced by using a purged capillary flow device that provided backflush capabilities by reversing column flow immediately after elution of the last compound of interest. Istotopically labelled internal standards were employed to improve the quality of the analytical results.     

Impact of biofumigation with solarization on degradation of pesticides and heavy metal accumulation

A greenhouse study was conducted to evaluate the effect of biofumigation (with sheep and chicken manure) combined with solarization on the dissipation of pesticides (pyrifenox, DDT and dieldrin), and on soil metals accumulation. The treatments consisted of a control, and soil disinfestations by biofumigation combined with solarization (B+S) for two, four, five, six consecutive years. B+S enhanced the dissipation of pyrifenox with regard to control treatment. Significant differences were not detected among plots disinfected with B+S for consecutive years. On the other hand, B+S had no effect on the dissipation of DDT and dieldrin, probably due to the resistance of these pesticides to microbial degradation and/or high temperatures. Biofumigation is considered to be an environmentally safe practice, since no accumulation of heavy metals such as Cd, Co, Cu, Cr, Pb, Ni, or Zn was observed after the subsequent application of organic matter through the treatments.     

Disruption of iron homeostasis and resultant health effects upon exposure to various environmental pollutants: A critical review

Environmental pollution has become one of the greatest problems in the world, and the concerns about environmental pollutants released by human activities from agriculture and industrial production have been continuously increasing. Although intense efforts have been made to understand the health effects of environmental pollutants, most studies have only focused on direct toxic effects and failed to simultaneously evaluate the long-term adaptive, compensatory and secondary impacts on health. Burgeoning evidence suggests that environmental pollutants may directly or indirectly give rise to disordered element homeostasis, such as for iron. It is crucially important to maintain concerted cellular and systemic iron metabolism. Otherwise, disordered iron metabolism would lead to cytotoxicity and increased risk for various diseases, including cancers. Thus, study on the effects of environmental pollutants upon iron homeostasis is urgently needed. In this review, we recapitulate the available findings on the direct or indirect impacts of environmental pollutants, including persistent organic pollutants (POPs), heavy metals and pesticides, on iron homeostasis and associated adverse health problems. In view of the unanswered questions, more efforts are warranted to investigate the disruptive effects of environmental pollutants on iron homeostasis and consequent toxicities.     

超声波萃取-毛细管气相色谱法测定土壤和底质中的25种有机氯农药研究

建立了超声波萃取、Florisil柱净化,SPB-5毛细管柱分离,ECD检测器测定土壤和底质中25种有机氯农药的方法.该方法的检出限为0.079 μg/kg ～1.2 μg/kg,加标回收率为73.1％ ～ 126.5％,相对标准偏差为3.3％ ～9.7％.实验结果证明,该方法灵敏度高、精密度高,操作快速简便,满足土壤和底质中有机氯农药的测定要求.