Modification of AOAC Multiresidue Method for Determination of Synthetic Pyrethroid Residues in Fruits, Vegetables, and Grains. Part II: Acetone Extraction System

1995 ◽  
Vol 78 (6) ◽  
pp. 1489-1496 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Chao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Limit Of Detection ◽  
Water Extraction ◽  
Multiresidue Analysis ◽  
Pyrethroid Insecticides ◽  
Multiresidue Method ◽  
Extraction Solvent ◽  
Acetone Water ◽  
Coefficients Of Variation ◽  
Extraction Solvents

Abstract To optimize conditions and to evaluate further a multiresidue method for pyrethroids, various extraction solvents and partitioning conditions were examined. Acetone and acetonitrile (for fruits and vegetables) and acetone–water and acetonitrile–water (for grains) were used as solvents with or without acetonitrile partitioning. Twenty crops fortified with 8 pyrethroid insecticides at low, medium, and high levels were analyzed. For limit of detection (LOD) levels, repeatability tests were completed with acetone–water as extraction solvent. Recoveries of 8 pyrethroid insecticides at LOD levels were 76.2–99.6%, with coefficients of variation (CVs) of 2.08–10.90% for narrow-bore capillary gas chromatography (GC) (n = 6) and 80.1–107.3% with CVs of 3.76–15.38% for wide-bore capillary GO (n = 6). Both acetone or acetone–water extraction with acetonitrile partitioning and acetonitrile or acetonitrile–water extraction with acetonitrile partitioning are suitable for multiresidue analysis of pyrethroid insecticides. However, acetonitrile and acetonitrile– water as extraction solvents were better than acetone and acetone–water at LOD-fortified levels. This finding was confirmed chromatographically with pear, cucumber, and barley control samples.

scholarly journals Modification of AOAC Multiresidue Method for Determining Synthetic Pyrethroid Residues in Fruits, Vegetables, and Grains. Part III: Studies of Analyte Stability and Method Ruggedness

1997 ◽  
Vol 80 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Cao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li
Keyword(s):  
Fruits And Vegetables ◽  
Synthetic Pyrethroids ◽  
Good Precision ◽  
Fruit And Vegetable ◽  
Multiresidue Analysis ◽  
Method Performance ◽  
Pyrethroid Insecticides ◽  
Vegetable Samples ◽  
Agriculture Products ◽  
The Stability

Abstract The stability of 8 synthetic pyrethroids in 9 crops during storage for 90 days were studied. The 8 pyrethroid insecticides were highly persistent in the 6 grains during storage. But their stabilities in 3 kinds of fruits and vegetables were different from those in the 6 grains: Most of them were degraded. Florisil purification conditions were studied with 6 batches of Florisil from 3 countries at various extents of deactivation and amounts. The best conditions of Florisil purification found in this present research agree with those found 1 year ago. The efficiencies of acetonitrile and acetone to extract the 8 pyrethroids from 6 fruit and vegetable samples were compared. The extraction efficiency of acetone was competitive with that of acetonitrile for the 6 fruit and vegetable samples. Method performance was evaluated by 6 analysts from different areas. The ruggedness tests demonstrate further that the proposed method is simple, accurate with good precision, and suitable for multiresidue analysis of pyrethroids in various agriculture products.

Modification of AOAC Multiresidue Method for Determination of Synthetic Pyrethroid Residues in Fruits, Vegetables, and Grains. Part I: Acetonitrile Extraction System and Optimization of Florisil Cleanup and Gas Chromatography

1995 ◽  
Vol 78 (6) ◽  
pp. 1481-1488 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Chao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fruits And Vegetables ◽  
Electron Capture Detection ◽  
Synthetic Pyrethroids ◽  
Capillary Gc ◽  
Pyrethroid Insecticides ◽  
Multiresidue Method ◽  
Polished Rice ◽  
The Individual

Abstract We present a multiresidue method for determination of synthetic pyrethroids in fruits, vegetables, and grains. The method is a modification of AOAC Method 970.52. Residues are extracted with acetonitrile (for fruits and vegetables) or acetonitrile–water (2 + 1) (for grains) and then transferred to hexane. Coextractives are removed by acetonitrile partitioning and open-column chromatography with deactivated Florisil. The final extract is analyzed by gas chromatography with electron capture detection (GC–ECD). An HP-17 wide-bore column is used to determine the total isomeric content of each insecticide, and a DB-5 narrow-bore column is used to determine the individual isomeric contents of each insecticide. The method was used to recover 8 pyrethroids (biphenthrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin, fluvalinate, fenvalerate, and deltamethrin) spiked at 0.01–4.0 mg/kg in 20 crops (apple, pear, peach, banana, grape, strawberry, potato, tomato, cucumber, pepper, cabbage, carrot, celery, polished rice, wheat, green gram, buckwheat, sorghum, maize, and barley). Recoveries of the 8 pyrethroid insecticides in 6 crops ranged from 83.8 to 112.8%, with a coefficient of variation (CV) of 2.00 to 12.09% for the narrow- bore capillary GC (n = 6) and from 82.8 to 106.4%, CV = 2.93–12.19%, for the wide-bore capillary GC (n = 6). The minimum detectable levels of 0.004–0.028 mg/kg (for fruits and vegetables) or 0.01–0.08 mg/kg (for grains) for the 8 pyrethroids are easy to detect.

scholarly journals The Ionic Associate of Metamizole as an Electrode-Active Component of a PVC Plasticized Membrane Electrode

Chemosensors ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Sarizhat D. Tataeva ◽  
Kurban E. Magomedov ◽  
Ruslan Z. Zeynalov ◽  
Naida D. Baygishieva ◽  
Viktorya S. Magomedova ◽  
...  
Keyword(s):  
Active Component ◽  
Limit Of Detection ◽  
Membrane Electrode ◽  
Ionic Associate ◽  
Selective Electrode ◽  
Coefficients Of Variation ◽  
Ion Associate ◽  
Phase Functions ◽  
Good Agreement

The technology for manufacturing a film membrane of the metamizole-selective electrode containing ion associate metamizole-octadecylammonium ODAH+MT− as an electrode active component (EAC) has been proposed. The main potentiometric characteristics of the metamizole-selective electrode have been determined. The expediency of the proposed design of the metamizole selective electrode for the determination of metamizole in dosage forms has been substantiated. The best composition of the membrane (wt.%) of the metamizole-selective electrode has corresponded to: ODAH+MT−—5.3; 2-nitrophenyloctylether—63.1; poly(vinyl chloride)—31.6. Electrode-active component in the membrane phase functions as an ion associate ODAH+MT−. Potentiometric characteristics of metamizole-selective electrode have been determined, which corresponded to: linear range 1 × 10−2–1 × 10−4 with limit of detection 4.58 × 10−5 M, electrode function slope −48.5 mV/dec., working interval pH 4.5–7.3, response time 60 s. The potentiometric coefficients of selectivity of the metamizole-selective electrode with respect to various ions have been determined. The possibility of determining metamizole in a medicinal product has been tested. The results of the analyses show good agreement between the two methods (relative error less than 7.0%) with coefficients of variation less than 5% for MT-SE and iodometric methods.

scholarly journals Organophosphate Pesticide Residue in Fruits and Vegetables

2018 ◽  
Vol 14 (2) ◽  
pp. 172-177
Author(s):  
Joko Sudarsono ◽  
Setyo Sri Rahardjo ◽  
Kisrini Kisrini
Keyword(s):  
Pesticide Residue ◽  
Fruits And Vegetables ◽  
Limit Of Detection ◽  
Sampling Procedure ◽  
Cross Sectional ◽  
Traditional Markets ◽  
Measurement Results ◽  
Cross Sectional Design ◽  
Vegetables And Fruits ◽  
Active Substances

The use of the pesticide which does not follow the procedure may potentially cause residue of pesticide to be left on vegetables and fruits sold in supermarkets and traditional markets. We aimed to find the pattern of pesticide usage and levels of residue found in plants. This study was an analytical observation with a cross-sectional design using detailed sampling procedure. We obtained the data of the pesticide residue concentration by conducting laboratory examinations on eight samples of cabbage and eight samples of tomatoes from traditional markets and supermarkets in the city of Solo. The data were tested using simple linear regression testing. The organophosphate measurement results showed no residues were detected, because it was below the Limit of Detection (LOD). We concluded that pesticides containing active substances were not used in the vegetables we tested or the active substances were no longer contained in the vegetables after harvesting.

scholarly journals Recovery and Elimination of Phenolic Pollutants from Water Using [NTf2] and [Nf2]-Based Ionic Liquids

2019 ◽  
Vol 9 (20) ◽  
pp. 4321
Author(s):  
Sas ◽  
Domínguez ◽  
González
Keyword(s):  
Ionic Liquids ◽  
Phenolic Compounds ◽  
Extraction Yield ◽  
Liquid Extraction ◽  
Industrial Growth ◽  
Extraction Solvent ◽  
Phenolic Pollutants ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
Extraction Solvents

At present, pollution is one of the most important problems worldwide. Industrial growth makes it necessary to develop techniques to remove pollutant substances from water, since water is an important natural source for life. One of these techniques is liquid–liquid extraction, which is used to remove phenolic compounds from wastewaters. Volatile organic compounds are used as common extraction solvents in liquid–liquid extractions; nevertheless, some of their properties, such as toxicity and volatility, make it necessary to replace them with other less toxic solvents. In this work, the capability of four ionic liquids, based on bis(trifluoromethylsulfonyl)imide [NTf2] and bis(fluorosulfonyl)imide [Nf2] anions and different cations to remove phenolic compounds from water was studied. The phenolic compounds used in this study were phenol, o-cresol, and 2-chlorophenol, and the effects of the extraction solvent and phenol structures were analyzed. For that, a liquid–liquid extraction was carried out, and the extraction yield was determined. In general, high extraction efficiencies were obtained for all studied systems, obtaining the highest extraction efficiencies using the pyrrolidinium cation-based ionic liquids.

Development of a Surface Plasmon Resonance–Based Immunoassay for Listeria monocytogenes

2005 ◽  
Vol 68 (4) ◽  
pp. 728-735 ◽  
Author(s):  
PAUL LEONARD ◽  
STEPHEN HEARTY ◽  
GARY WYATT ◽  
JOHN QUINN ◽  
RICHARD O'KENNEDY
Keyword(s):  
Surface Plasmon Resonance ◽  
Listeria Monocytogenes ◽  
Surface Plasmon ◽  
Polyclonal Antibody ◽  
Plasmon Resonance ◽  
Limit Of Detection ◽  
Chip Surface ◽  
Metal Affinity ◽  
Coefficients Of Variation ◽  
Internalin B

A polyclonal antibody was produced against Internalin B (InlB)–enriched extract and used to develop an inhibition assay to detect Listeria monocytogenes cells in solution using surface plasmon resonance. The gene sequence encoding for the InlB protein was cloned into a Qiagen pQE-60 vector, expressed in Escherichia coli, and purified by immobilized metal affinity chromatography. Protein G–purified anti-InlB–enriched extract polyclonal antibody was incubated with various concentrations of L. monocytogenes cells and subsequently injected over a purified-recombinant InlB (rInlB)–immobilized CM5 sensor chip surface. A decrease in antibody binding response was observed with increasing L. monocytogenes cell concentrations. Intraday and interday assay variability studies were carried out to evaluate precision and reproducibility. The assay had a limit of detection of less than 2 × 105 cells per ml and could be successfully reproduced with coefficients of variation of between 2.5 and 7.7%.

scholarly journals Enzyme Immunoassay for Measuring Aflatoxin B1 in Legal Cannabis

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 265 ◽  
Author(s):  
Fabio Di Nardo ◽  
Simone Cavalera ◽  
Claudio Baggiani ◽  
Matteo Chiarello ◽  
Marco Pazzi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Aflatoxin B1 ◽  
Analytical Methods ◽  
Limit Of Detection ◽  
Direct Analysis ◽  
Aflatoxin Contamination ◽  
Throughput Capacity ◽  
Human Consumption ◽  
The European Union ◽  
Coefficients Of Variation

The diffusion of the legalization of cannabis for recreational, medicinal and nutraceutical uses requires the development of adequate analytical methods to assure the safety and security of such products. In particular, aflatoxins are considered to pose a major risk for the health of cannabis consumers. Among analytical methods that allows for adequate monitoring of food safety, immunoassays play a major role thanks to their cost-effectiveness, high-throughput capacity, simplicity and limited requirement for equipment and skilled operators. Therefore, a rapid and sensitive enzyme immunoassay has been adapted to measure the most hazardous aflatoxin B1 in cannabis products. The assay was acceptably accurate (recovery rate: 78–136%), reproducible (intra- and inter-assay means coefficients of variation 11.8% and 13.8%, respectively), and sensitive (limit of detection and range of quantification: 0.35 ng mL−1 and 0.4–2 ng mL−1, respectively corresponding to 7 ng g−1 and 8–40 ng g−1 ng g−1 in the plant) and provided results which agreed with a HPLC-MS/MS method for the direct analysis of aflatoxin B1 in cannabis inflorescence and leaves. In addition, the carcinogenic aflatoxin B1 was detected in 50% of the cannabis products analyzed (14 samples collected from small retails) at levels exceeding those admitted by the European Union in commodities intended for direct human consumption, thus envisaging the need for effective surveillance of aflatoxin contamination in legal cannabis.

scholarly journals Preparative Method for Isolating α-Zearalenol and Zearalenone Using Extracting Disk

1999 ◽  
Vol 82 (1) ◽  
pp. 90-94 ◽  
Author(s):  
George M Ware ◽  
Yuhong Zhao ◽  
Shia S Kuan ◽  
Allen S Carman
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Control Sample ◽  
Preparative Method ◽  
Reversed Phase ◽  
Fluorescence Detector ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Standard Calibration ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method is described for the determination of zearalenol and zearalenone in corn. Zearalenol and zearalenone are extracted from corn with methanol–water (1+1) and cleaned up using a solid-phase extraction (SPE) disk, separatedon a reversed-phase analytical column, and detected with a fluorescence detector. The SPE disk concentrated and cleanly separated zearalenol and zearalenone from sample interferences. Standard calibration curves for zearalenol and zearalenone for the concentration range 25–500 ng/mL were linear. The small extract disk had a column capacity equivalent to 1 g extracted corn. Zearalenol and zearalenone were added at levels ranging from 10 to 2000 ng/g to a control sample that contained no detectable levels of zearalenol and zearalenone. Both toxins were recovered from spiked samples at 106.3 and 103.8%, with coefficients of variation of 7.6 and 13.0%, respectively. The method has an estimated reliable limit of detection and limit of quantitation around 10 and 40 ng/g for each toxin, respectively.

scholarly journals Spectroscopic and Structural Analyses of Opuntia Robusta Mucilage and Its Potential as an Edible Coating

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 466 ◽  
Author(s):  
Aurea Bernardino-Nicanor ◽  
José Montañez-Soto ◽  
Eloy Conde-Barajas ◽  
María Negrete-Rodríguez ◽  
Gerardo Teniente-Martínez ◽  
...  
Keyword(s):  
Quality Characteristics ◽  
Edible Coating ◽  
Extraction Solvent ◽  
Solvent Influence ◽  
Pectic Substances ◽  
Ft Ir ◽  
Lycopene Content ◽  
Extraction Solvents ◽  
Ir And Raman ◽  
Aggregation Level

Mucilage extracted from the parenchymatous and chlorenchymatous tissues of Opuntia robusta were obtained using water or ethanol as the extraction solvent. The changes in the different tissues by using different extraction solvents were evaluated via scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) and Raman spectroscopy; in addition, the effect of mucilage coating on the various quality characteristics of tomato (Lycopersicum sculentum) was evaluated. The SEM results showed that the mucilage extracted from the parenchyma had a higher aggregation level that the mucilage extracted from the chlorenchyma. The presence of three characteristic bands of pectic substances in the FT-IR spectra between 1050 and 1120 cm−1 indicated that the mucilage extracted from the parenchymatous tissue had a higher content of pectic compounds than the mucilage extracted from the chlorenchymatous tissue. It was also observed in the Raman spectra that the level of pectic substances in the mucilage extracted from the parenchymatous was higher than that in the mucilage extracted from the chlorenchymatous tissue. The mucilage extracted from the parenchymatous tissue was more effective as an edible coating than the mucilage extracted from the chlorenchymatous tissue. Tomatoes covered with mucilage showed significantly enhanced firmness and reduced weight loss. The uncoated tomatoes showed higher lycopene content than the coated tomatoes on the 21st day. This study showed that the Opuntia robusta tissue and extraction solvent influence mucilage characteristics and that Opuntia robusta mucilage is a promising edible coating.

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