scholarly journals The development of methods for the determination of residues of the insecticide pymetrozine in water, soil, cucumber and rape

2019 ◽  
pp. 79-87
Author(s):  
Mikhail F. Zayats ◽  
Sergey M. Leschev
Keyword(s):  
Experimental Data ◽  
Orthophosphoric Acid ◽  
Residue Level ◽  
Inorganic Salts ◽  
Diode Array ◽  
The European Union ◽  
Optimal Conditions ◽  
Ultraviolet Detection ◽  
Maximum Residue Level

Based on the literature data on the solubility of pymetrozine in water and organic solvents, as well as experimental data on the extraction of pymetrozine from water, soil and plant matrices, the optimal conditions for the extraction of pymetrozine from water; soil; cucumber; rape seeds, oil and green pods were selected. The conditions for cleaning extracts were selected as well. At the first stage, acetonitrile, a mixture of dichloromethane – isopropanol, or a mixture of dichloromethane – methanol in the presence or absence of inorganic salts were used for extraction of the pesticide. Pymetrozine was found to be a highly hydrophilic substance. For the purification of extracts of pymetrozine from plant matrices the extraction systems hexane – 0.02 mol/L aqueous solution of orthophosphoric acid, hexane or chloroform – aqueous solutions of ammonium sulfate were successfully used. The samples, obtained after this treatment, were pure enough to determine the residual amounts of pymetrozine in them at the maximum residue level (MRL), determined in Russia and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.

scholarly journals Determination of the bifenazate insecticide in apples and cucumbers by high performance liquid chromatography

2019 ◽  
Vol 55 (4) ◽  
pp. 422-428
Author(s):  
M. F. Zayats ◽  
S. M. Leschev
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Diode Array ◽  
The European Union ◽  
Optimal Conditions ◽  
Plant Materials ◽  
Ultraviolet Detection ◽  
Maximum Residue Level ◽  
Distribution Constants

Based on the distribution constants of biphenazate, obtained experimentally and also calculated from literature data on the solubility of biphenazate in water and organic solvents, as well as experimental data on the extraction of biphenazate from plant matrices by various extractants, we selected the optimal conditions for extracting biphenazate from apples and cucumbers. The conditions for the purification of the extracts were also selected. Acetonitrile in the presence of ammonium sulfate and hexane was used for extraction of the pesticide. Purification of extracts of plant materials was carried out by partitioning between hexane and water-acetonitrile mixture. The samples obtained after this treatment were pure enough to determine the residual amounts of biphenazate in them at the maximum residue level determined in Belarus and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.

Residual 1,2-dibromoethane in mango, capsicum, passionfruit and papaw after fumigation against Queensland fruit fly, Dacus tryoni (Froggatt)

1985 ◽  
Vol 25 (1) ◽  
pp. 214
Author(s):  
KJ Melksham ◽  
HE Munro
Keyword(s):  
Fruit Fly ◽  
Storage Conditions ◽  
Residue Level ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray ◽  
Maximum Residue Level ◽  
Low Levels ◽  
Rate Of Dissipation ◽  
Time Required

Residual 1,2-dibromoethane (EDB) was measured in mango, capsicum, passionfruit and papaw following treatment with biologically effective levels of EDB. Post-fumigation forcedairing periods, storage conditions and times of storage were varied. The duration of the forced-airing period after fumigation had no significant effect on the rate of dissipation of EDB from mango. Fumigated mango required storage at 21� for at least 3 days before EDB levels fell to the maximum residue level (MRL) of 0.1 mg/kg. Cool storage of mango extended the time required for the EDB level to fall to the MRL to at least 6 days. Fumigated capsicum stored at 21�C required 2 days for EDB levels to fall to the MRL while, with fumigated papaw, this took at least 4 days. Even after storage for 7 days, EDB levels in fumigated passionfruit exceeded the MRL so the fumigation procedure was unsuitable for use with passionfruit. A kinetic model was proposed which explained the behaviour of EDB in the various trials and in other literature reports. All samples were analysed by X-ray fluorescence spectrometry (X-RF) and many results were confirmed more specifically and more sensitively by gas chromatography-mass spectrometry. Comparison ofresults by these two methods, including the results of samples spiked with low levels of EDB, helped remove doubts about the suitability of X-RF for the determination of residual EDB.

Determination of Chloramphenicol Residues in Aquatic Products Using Immunoaffinity Column Cleanup and High Performance Liquid Chromatography with Ultraviolet Detection

2013 ◽  
Vol 96 (4) ◽  
pp. 897-901 ◽  
Author(s):  
Qing-Jie Zhang ◽  
Tao Peng ◽  
Dong-Dong Chen ◽  
Jie Xie ◽  
Xiong Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Ammonium Hydroxide ◽  
Optimal Conditions ◽  
Immunoaffinity Column ◽  
Ultraviolet Detection ◽  
Aquatic Products ◽  
Highly Sensitive ◽  
The Mean

Abstract A method based on HPLC with UV detection was developed for the quantitative determination of chloramphenicol (CAP) residues in aquatic products. The samples were extracted with ethyl acetate–ammonium hydroxide (98 + 2, v/v), followed by a cleanup step using an immunoaffinity column. The analytes were determined by HPLC-UV. Optimal conditions for the extraction and cleanup procedures are described. The linear regression equation was y = 91.47x – 8.60 with R2 = 0.9998 (y = peak area and x = CAP concentration) and showed a good reproducibility. The LOQ was 0.25 μg/kg for determining CAP spiked in the aquatic products. The mean recoveries of CAP from fish and shrimp samples fortified at 0.25–1.0 μg/kg were 88.7–93.1 and 92.0–97.3%, respectively; the repeatability RSDs were less than 8.1%. It was concluded that the method is simple, highly sensitive, and low cost for quantitatively measuring CAP residues in aquatic products. Analyte identification was confirmed by HPLC/MS/MS analysis.

scholarly journals Determination of heavy metals and organochlorine pesticides in the leaves and flowers from linden trees in Kırklareli province

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Osman Üner ◽  
Cihan Torlak ◽  
Cemile Özcan
Keyword(s):  
Heavy Metals ◽  
Residue Level ◽  
Quechers Method ◽  
Flame Atomic Absorption Spectroscopy ◽  
Flame Atomic Absorption ◽  
Maximum Residue Level ◽  
Gas Chromatography Mass Spectroscopy ◽  
Tilia Tomentosa ◽  
Organochloride Pesticides

For five different regions in Kırklareli province, heavy metals; such as Pb, Ni, Cu, Mn, Cd, Cr, Co, Zn, Mo, and Fe in the mixture of leaves and flowers from linden trees (Tilia tomentosa L.) were analyzed by using flame atomic absorption spectroscopy after the samples were dissolved with microwave method. Also, organochloride pesticides; such as ∑BHC: [α-BHC, β-BHC, γ-BHC, and δ-BHC], ∑DDT: [4,4’-DDD, 4,4’-DDE, and 4,4’-DDT], α-Endosulfan, β-Endosulfan, Endosulfan sulfate, Heptachlor, Heptachlor-endo-epoxide, Aldrin, Dieldrin, Endrin aldehyde, Endrin ketone, Endrin and Methoxychlor in these samples were determined by utilizing gas chromatography mass spectroscopy after the samples were prepared for analyses by using QuEChERS method. The metal concentrations in the samples were in the range of 45.3 to 268 mg/kg for Mn, 0.25 to 18.8 mg/kg for Cu, 11.5 to 46.1 mg/kg for Zn, 128 to 1310 mg/kg for Fe, 10.4 to 38.6 mg/kg for Mo, 0.82 to 1.34 mg/kg for Cd, 0 to 6.45 mg/kg for Ni, 0 to 19.2 mg/kg for Pb, and 0 to 8.25 mg/kg for Cr. Moreover, the concentrations of organochloride pesticides in samples were usually determined to be lower than their maximum residue level values given the pesticide residue limit regulation of Turkish Food Codex. 

scholarly journals Extraction-photometric determination of osmium using quaternary water-thiopyrine-trichloroacetic and orthophosphoric acid system

2020 ◽  
Vol 99 (3) ◽  
pp. 61-65
Author(s):  
L.S. Egorova ◽  
◽  
E.A. Leites ◽  
Keyword(s):  
Ascorbic Acid ◽  
Organic Solvent ◽  
Orthophosphoric Acid ◽  
Photometric Determination ◽  
Model Mixture ◽  
Acid System ◽  
Optimal Conditions ◽  
Liquid Component ◽  
Effect Of Copper

The article is devoted to the extraction-photometric determination of osmium. The aim was to modify the well known extraction-photometric determination of osmium by replacing chloroform, used as an organic solvent in a traditional extraction system, on to water, which is the only liquid component in the layering system. This made it possible to eliminate the toxic organic solvent from the system. The optimal conditions for the osmium extraction were selected, taking with the fact that the consumption of thiopyrine, as an expensive reagent, should be minimal. The results of the developed methodology for determining microgram amounts of osmium with thiopyrine were presented by the example of a model mixture corresponding to the composition of a platinum sponge. The interfering effect of Al (lII), B (lII), Bi (IIl), Fe (llI), Au (lII), lr (II), Cd (ll), Co (II), Ca (II), Si ( IV), Mg (II), Mn (II), Cu (Il), Mo (VI), As (V), Ni (lI), Sn (lV), Pd (Il), Rh (II), Pb (II), Ag (I), Sb (IIl), Te (IV), Cr (IlI), Zn (Il) contained in a platinum sponge was investigated. The interfering effect of copper has been established, which is eliminated by masking with ascorbic acid.

scholarly journals Determination of residue of diazinon and carbosulfan in brinjal and quinalphos in yard long bean under supervised field trial

1970 ◽  
Vol 33 (3) ◽  
pp. 503-513 ◽  
Author(s):  
KH Kabir ◽  
MA Rahman ◽  
MS Ahmed ◽  
MDH Prodhan ◽  
MW Akon
Keyword(s):  
Key Words ◽  
Field Trial ◽  
Field Trials ◽  
Residue Level ◽  
Maximum Residue Level

The present study was undertaken to detect and quantify the left over residue of Diazinon and Carbosulfan in brinjal and Quinalphos in yard long bean and comparison between the detected residue level with maximum residue level (MRL) set by FAO (1970). Three supervised field trials (two for brinjal and one for yard long bean) were carried out sprayed with the field dose (1.5 ml/L of water) of Diazinon, Carbosulfan, and Quinaiphos. Samples were collected daily after spraying till residue were found. In case of Diazinon, left over residue was found upto 6 days after spray (DAS), and upto 3 DAS, the level of residue was above the MRL. Carbosulfan residue was detected till 7 DAS and the detected quantity of residue was above MRL upto 3 DAS. Left over residue of Quinalphos in yard long bean sample was detected upto 6 DAS and upto 4 DAS the level of residue was above the MRL. Key Words: Residue, Diazinon, Carbosulfan, Quinalphos. brinjal, yard long bean. doi:10.3329/bjar.v33i3.1609 Bangladesh J. Agril. Res. 33(3) : 503-513, September 2008

scholarly journals Simultaneous Determination of Six Triazolic Pesticide Residues in Apple and Pear Pulps by Liquid Chromatography with Ultraviolet Diode Array Detection

2001 ◽  
Vol 84 (5) ◽  
pp. 1543-1550 ◽  
Author(s):  
Carlo Bicchi ◽  
Chiara Cordero ◽  
Patrizia Rubiolo ◽  
Alessandro Occelli
Keyword(s):  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
Pesticide Residues ◽  
Mobile Phase ◽  
Solid Phase ◽  
Diode Array ◽  
Diode Array Detection ◽  
Ultraviolet Detection ◽  
Array Detection

Abstract A method is described for the simultaneous determination of diclobutrazol, flusilazole, flutriafol, hexaconazole, paclobutrazol, and tetraconazole in apple and pear pulps used in baby food at a limit of 0.01 mg/kg. Apple and pear pulp samples are subjected to selective solid-phase microdispersion (SPMD) with SPE-ED Matrix-38 and acetone–cyclohexane, and the extracts are cleaned up on a Florisil cartridge with hexane–cyclohexane–acetone. The extracts are then analyzed by liquid chromatography with ultraviolet detection, using an octadecylsilane column with a gradient-programmed acetonitrile–water mobile phase. Recoveries were determined by spiking apple and pear pulps with the 6 pesticides under investigation at 0.1, 0.05, 0.03, and 0.01 mg/kg. Six determinations were performed at each level for each pesticide. Recoveries were ≥70% at the 0.01 mg/kg level.

An Interlaboratory Comparative Study on the Quantitative Determination of Glyphosate at Low Levels in Wheat Flour

2015 ◽  
Vol 98 (6) ◽  
pp. 1760-1768 ◽  
Author(s):  
Emanuela Simonetti ◽  
Gérald Cartaud ◽  
Robert M Quinn ◽  
Ilaria Marotti ◽  
Giovanni Dinelli
Keyword(s):  
Quantitative Determination ◽  
Performance Assessment ◽  
Wheat Flour ◽  
Residue Level ◽  
Analytical Determination ◽  
Maximum Residue Level ◽  
Organic Products ◽  
Low Levels ◽  
Analytical Laboratories

Abstract In recent years, the use of glyphosate has dramatically increased worldwide, and there is growing concern about contamination of organic products caused by its heavy use on neighboring fields. Glyphosate is found as a residue not only in soil, plants, and groundwater but also in humans and animals. Considering the controversy on glyphosate maximum residue level in foodstuff and the difficulties in its analytical determination, the main purpose of the present paper was to investigate the competence and accuracy of 13 accredited European laboratories in determining glyphosate in wheat flour at a level close to their reporting limit of 10 μg/kg. According to the results of this performance assessment, the laboratories were not able to quantify glyphosate at trace levels. Therefore, their specified reporting limits of 10 μg/kg were not supported by their results, and a reporting limit of around 50 μg/kg of glyphosate in flour seems to be more appropriate to guarantee reliable and robust results. The widespread use of glyphosate and its harmfulness to humans make its detection at trace levels a primary goal for analytical laboratories. This is achievable through the improvement of QA and/or the optimization of the method of analysis used for glyphosate detection.

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