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A simple, sensitive and rapid method is proposed for simultaneous determination of 120 various classes of herbicides in oilseed samples. A one-step QuEChERS-based approach to extraction and cleanup has been developed. LC–MS/MS was used to evaluate the proposed sample treatment methodologies. The new one-step QuEChERS strategy was compared to other methodologies previously used for elimination of co-extracts from fatty matrices. For validation purposes, recovery studies were carried out at 5, 50 and 500 µg kg−1 levels for rapeseed, sunflower seeds and soybean. The optimized method yielded a small matrix effect (−20–20%) for 82% of the tested compounds. We was found to reduce matrix effects more effectively without significantly decreasing analyte recoveries. Throughout the validation experiments, 70–120% overall recoveries were achieved with RSDs < 20% for most herbicides. The validated method was employed in analysis of ninety real rapeseed samples. © 2017 Elsevier Ltd

Kaczynski P.,Institute of Plant Protection National Research Institute
Food Chemistry | Year: 2017

This study reports an innovative and sensitive procedure for analysis of difficult high polar herbicides (HPH) in diverse foods of plant origin. The QuPPe (Quick Polar Pesticides) method followed by determination by LC-MS/MS was modified. Chromatographic conditions, extraction, clean-up, and matrix effect were studied. Several liquid chromatography stationary and mobile phases were evaluated, and it was found that hydrophilic interaction chromatography (HILIC) gives good retention and sensitivity. An acidified methanol-water mixture was used as an effective extraction solvent of eleven HPH. Dispersive solid-phase clean-up sorbents (C18, GCB, Florisil, chitosan and graphene) were evaluated. The efficiency of the method was examined using data on recovery, precision and matrix effects. High extraction yields were achieved, and recoveries were within the 64–97% range with relative standard deviations <20% for all HPH in all commodities. Low matrix effects were observed when graphene was used during clean-up of onion extract and when chitosan was used for wheat, potato and pea extract. © 2017 Elsevier Ltd

A triple quadrupole GC-QqQ-MS/MS method was optimized for multiresidue analysis of over 180 pesticides in blackcurrants. The samples were prepared by using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) analytical protocol. To reduce matrix co-extractives in the final extract, the supernatant was cleaned up by dispersive-solid phase extraction (dispersive-SPE) with a mixture of sorbents: primary secondary amine (PSA), octadecyl (C18) and graphitized carbon black (GCB). The validation results demonstrated fitness for purpose of the streamlined method. The overall recoveries at the three spiking levels of 0.01, 0.05 and 0.2 mg kg-1 spanned between 70% and 116% (102% on average) with relative standard deviation (RSD) values between 3% and 19% except for chlorothalonil (23%). Response linearity was studied in the range between 0.005 and 0.5 mg kg-1. The matrix effect for each individual compound was evaluated through the study of ratios of the slopes obtained in solvent and blackcurrant matrix. The optimized method provided small matrix effect (<10%) for 77% of the compounds, whereas only for 14%, 5% and 4% compounds, the matrix effect was 10-20%, 20-30% and >30%, respectively. Following the application of "top-down" approach, the expanded measurement uncertainty was estimated as being 21% on average (coverage factor k=2, confidence level 95%). If compared with samples of other crops, the analyses of blackcurrants revealed a high percentage of exceedance of the legislative maximum residue levels (MRLs), as well as some instances of the detection of pesticides unapproved on this crop. © 2013 Elsevier B.V. All rights reserved.

Matyaszek A.,Institute of Plant Protection National Research Institute
Roczniki Państwowego Zakładu Higieny | Year: 2013

Poland is a leading grower/producer of berries in Europe that are either eaten raw or processed. As well as berries this includes fruit such as grapes, strawberries and other small fruits. Testing for the presence of active substances in Plant Protection Products, (PPP), in such fruit is however important, as part of measures taken to minimise human intake. To determine the incidence of pesticide residues in berries harvested from South-Eastern Poland in 2009-2011. . Chromatographic separation followed by analytical detection was performed on 250 samples of various test fruits using an accredited methodology: GC/ECD/NPD, together with spectrophotometric detection wherever necessary, according to PN-EN ISO/IEC 17025. As part of previous monitoring, 126 active substances were identified in 2009, 132 in 2010 and 153 in 2011; levels were compared to Maximum Residue Limits (MRLs). RESULTS;. Analyses showed that 46.4% of samples contained PPPs of which 4% exceeded the MRL. The most were found in raspberries, (58.8% of all tested), followed by 58.3% redcurrants, and gooseberries as well as 50% grapes. The most frequently found active substances of PPPs were pyrimethanil (15.6%), dithiocarbamates (12.4%), procymidone (8%), cyprodinil (5.6%) and difenoconazole (5.2%). The highest MRL exceedances were found in blackcurrants. Testing also revealed many examples of pesticides not recommended for the protection of specific crops: propiconazole in gooseberries, cyprodinil, flusilazole, iprodione, pyrimethanil in blackcurrants and folpet and captan in raspberries. Furthermore, active substances whose use in PPPs have been forbidden since 2008 were also detected, ie. endosulfan in blackcurrants and strawberries, fenitrothion in black and red currants as well as procymidone in raspberries, blackcurrants and strawberries. These data are consistent to those obtained from the whole of Poland and the European Union (EU). Most pesticides were present in raspberries, redcurrants, gooseberries and grapes of which fungicides were the most frequently detected. These results are in keeping with other similar studies.

Szpyrka E.,Institute of Plant Protection National Research Institute | Walorczyk S.,Institute of Plant Protection National Research Institute
Food Chemistry | Year: 2013

Dissipation behaviour of simultaneously applied fungicides fluquinconazole and pyrimethanil was studied in/on apples intended for baby food production (cultivars Jonagold Decosta, Golden and Champion). The apples were sprayed at two dosages to control the pathogen Venturia inaedequalis (Cooke) Aderh. A validated gas chromatographic method (GC-ECD and GC-NPD) was used to determine the fungicides residues, the analytical performance of which was highly satisfactory with expanded uncertainties not higher than 15% (coverage factor k = 2, confidence level 95%) The dissipation of the fungicide residues was fitted to the experimental data assuming pseudo first-order decay kinetics (R 2 between 0.897 and 0.992). To obtain the fungicide residues below 0.01 mg/kg, which is the default maximum residue level for food intended for infants and young children, the application of the fungicides under study should be carried out 2 or 3 months before harvest at the lower (1.0 L/ha) and the higher (1.5 L/ha) recommended dose, respectively. © 2013 Elsevier Ltd. All rights reserved.

Wieczorek P.,Institute of Plant Protection National Research Institute | Obrepalska-Steplowska A.,Institute of Plant Protection National Research Institute
Plant Molecular Biology Reporter | Year: 2015

In higher plants, evolutionarily conserved processes playing an essential role during gene expression rely on small noncoding RNA molecules (sRNA). Within a wide range of sRNA-dependent cellular events, there is posttranscriptional gene silencing, the process that is activated in response to the presence of double-stranded RNAs (dsRNAs) in planta. The sequence-specific mechanism of silencing is based on RNase-mediated trimming of dsRNAs into translationally inactive short molecules. Viruses invading and replicating in host are also a source of dsRNAs and are recognized as such by cellular posttranscriptional silencing machinery leading to degradation of the pathogenic RNA. However, viruses are not totally defenseless. In parallel with evolving plant defense strategies, viruses have managed a wide range of multifunctional proteins that efficiently impede the posttranscriptional gene silencing. These viral counteracting factors are known as suppressors of RNA silencing. The aim of this review is to summarize the role and the mode of action of several functionally characterized RNA silencing suppressors encoded by RNA viruses directly involved in plant–pathogen interactions. Additionally, we point out that the widely diverse functions, structures, and modes of action of viral suppressors can be performed by different proteins, even in related viruses. All those adaptations have been evolved to achieve the same goal: to maximize the rate of viral genetic material replication by interrupting the evolutionary conserved plant defense mechanism of posttranscriptional gene silencing. © 2014, The Author(s).

Walorczyk S.,Institute of Plant Protection National Research Institute | Drodynski D.,Institute of Plant Protection National Research Institute | Gnusowski B.,Institute of Plant Protection National Research Institute
Talanta | Year: 2011

A new multiresidue method for the efficient screening, identification and quantification of over 160 pesticides belonging to different chemical classes in red, rose and white wines have been developed. The analysis was based on gas chromatographic-tandem quadrupole mass spectrometric determination (GC-QqQ-MS/MS). An optimization strategy involved the selection of buffering conditions and sorbents for dispersive-solid phase extraction (dispersive-SPE) in order to achieve acceptably high recoveries and reduce co-extractives in the final extracts. As a result, the optimized procedure allowed us to obtain consistent recoveries of the target pesticides including problematic ones such as captan, chlorothalonil, dichlofluanid, folpet and tolylfluanid. The attained recoveries were typically between 80 and 110% (89% on average) with RSD values typically lower than 10% (8% on average) at three spiking levels of 0.01, 0.05 and 0.2 mg kg-1. Linearity was studied in the range between 0.005 and 0.2 mg kg-1 using pesticide standards prepared both in pure solvent and in the presence of matrix, showing coefficients of determination (R 2) higher than 0.99 for all the pesticides except for desmedipham, thiabendazole and thiamethoxam in pure solvent. The study of the ratio of the slopes obtained in solvent and in matrix provided information about the matrix effects, which was <10%, 10-20% and >20% for 33, 36 and 31% of the studied pesticides, respectively. To improve accuracy, matrix matched standards were always used for calculation of the quantification results. The expanded uncertainties were estimated by using a "top-down" approach as being 17% on average (coverage factor k = 2, confidence level 95%). Finally, the method was used with success to detect and quantify pesticide residues in commercial wines. © 2011 Elsevier B.V. All rights reserved.

Slowik-Borowiec M.,Institute of Plant Protection National Research Institute
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2016

Dissipation of simultaneously applied insecticides alpha-cypermethrin and lambda-cyhalothrin was studied in a minor crop, aboveground part of white mustard (Sinapis alba L.). A validated gas chromatographic method (GC-ECD/NPD) was used to determine insecticide residues. Analytical performances were very satisfactory, with expanded uncertainties not higher than 14% (coverage factor k = 2, confidence level 95%). Dissipation of alpha-cypermethrin and lambda-cyhalothrin in white mustard followed first-order kinetics (R2 between 0.953 and 0.995), with half-lives of 3.1–4.6 and 2.9–3.7 days respectively. Based on the results of this two-year study and the relevant residue regulation, alpha-cypermethrin and lambda-cyhalothrin treatments can be considered safe for crop protection, feeding animals and the environment. © 2016 Taylor & Francis Group, LLC

Kowalska J.,Institute of Plant Protection National Research Institute
Acta Agriculturae Scandinavica Section B: Soil and Plant Science | Year: 2014

Oilseed rape (Brassica napus L.) is a very difficult crop to cultivate organically. Only few organic methods are effective in reducing damage from insects and diseases. The current investigation assessed the use of the beneficial ascomycete Trichoderma asperellum (Samuels, Lieckf & Nirenberg) and a trap crop of Brassica rapa L. turnip rape cv. "Brachina," both with and without an application of slurry fertilizer, for pest suppression and yield enhancement of winter oilseed rape cv. "Californium." The presence of the trap crop significantly increased 1000 grain weight but not total yield or lipid content of the oilseed rape because turnip rape was not attractive enough to prevent colonization of the principal crop. Increase in 1000 grain weight, lipid content, and total seed yield were found in oilseed rape sprayed with three applications of T. asperellum, but the ascomycete had no influence on the insect pests observed. The effects of the fertilizer are about equal to the effects of the fungus on 1000 grain weight and on lipid content. © 2014 Taylor & Francis.

Slowik-Borowiec M.,Institute of Plant Protection National Research Institute
Food Analytical Methods | Year: 2015

A convenient analytical method for quantitative characterization of 46 pesticides in fresh peppermint (a plant with high chlorophyll content) has been developed. The plant samples were extracted with acetonitrile and then with graphitized carbon black (GCB), and primary–secondary amine (PSA) was added to dispersive solid phase extraction tubes in order to reduce chlorophyll content in the resultant extracts for the purpose of improving analytical performance in terms of recovery, precision, linearity and measurement uncertainty. The analytical method was established by using the technique of gas chromatography coupled with electron capture and nitrogen phosphorus detection (GC/ECD/NPD). Samples spiked with the target pesticides at the concentration level 0.004 mg/kg and higher levels (depending on the compound) yielded average recoveries in the range of 70–120 % with relative standard deviations (RSDs) 0–15 %, except for chlorothalonil, folpet, imazalil and spiroxamine and displayed very good linearity (R2 > 0.99) for nearly all of the analytes. The matrix effect (ME) was evaluated for 17 compounds through the study of ratios of the slopes obtained in the solvent and peppermint matrix. Percentage values of the ME (% ME) were in a range of −25 % (bifenthrin) to 15 % (azoxystrobin); however, matrix effects for the vast majority of pesticides were small, showing suppression or enhancement in the range from 0 to ±7 %. Expanded measurement uncertainties were estimated, with the employment of a top-down empirical model, as being between 6 and 24 % and yielding an average value of 15 % (coverage factor k = 2, confidence level 95 %). This is significantly less than the maximum threshold value of 50 % recommended by European Union guidelines, which clearly demonstrates suitability for the purpose of the proposed method. © 2014, Springer Science+Business Media New York.

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