GLC Determination of Residues of Disulfoton, Oxydemetonmethyl, and Their Metabolites in Tobacco Plants

Abstract Residues of disulfoton and five of its metabolites on disulfoton-treated tobacco plants were analyzed as follows: Plant extracts were separated into three fractions by liquid chromatograpliy and an aliquot of each was analyzed by GLC, using a flame photometric phosphorus detector. The tobacco caused no background interference in the GLC analysis. Recoveries of five of the six compounds from plants fortified at the 1 ppm level were 88 to 100%; the sixth was unstable in tobacco and its oxidation products were detected. GLC response was linear up to the 250 ng level and the sensitivity was 0,01 to 0.04 ppm. The general procedure was also successfully applied to oxydemetonmethyl and its sulfone, which are chemically similar to two of the disulfoton metabolites.

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Preliminary Studies on Weathering of Chlordane Residues

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/48.5.952 ◽

1965 ◽

Vol 48 (5) ◽

pp. 952-954

Author(s):

Alfred D Thruston

Keyword(s):

Gas Chromatography ◽

Quantitative Determination ◽

Plant Extracts ◽

Room Temperature ◽

Agricultural Products ◽

Qualitative And Quantitative ◽

Chromatographic Peaks ◽

The Many ◽

Ppm Level

Abstract The qualitative and quantitative determination of chlordane residues on raw agricultural products has been best achieved by gas chromatography techniques. While good recoveries (90–100% at the 0.1 ppm level) have been obtained from plant extracts with added standard chlordane, weathered chlordane residues show changes in number and size of gas chromatographic peaks. Chlordane at the 50 µg level, when exposed to the air at room temperature over a period of time, showed progressive decomposition and loss of the many components that make up chlordane.

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Determination of Chlorinated Methylthiobenzenes and Their Sulfoxides and Sulfones in Fish

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/67.6.1082 ◽

1984 ◽

Vol 67 (6) ◽

pp. 1082-1085

Author(s):

Albert M Gardner ◽

Akiva Abramovitch

Keyword(s):

Methylene Chloride ◽

Sulfur Oxidation ◽

Oxidation Products ◽

Detection Level ◽

Florisil Column ◽

Fish Samples ◽

Aoac Method ◽

Layer Chromatography ◽

Ppm Level

Abstract A procedure was developed to determine chlorinated methylthiobenzenes and their respective sulfur oxidation products in fish. Perch samples fortified at the 0.1 ppm level with 2,4,5-trichloromethylthiobenzene, pentachloromethylthiobenzene, and their sulfoxides and sulfones were extracted and cleaned up using an adaptation of the official AOAC method for multiple residues of organochlorine pesticides. The Florisil column cleanup was modified; 200 raL 6% petroleum etherethyl ether eluted the methylthiobenzenes, 200 mL 50% PE-EE eluted the sulfones, and 200 mL EE eluted the sulfoxides. Recoveries determined by electron capture (ECD) gas chromatography (GC) were 75- 101% for the methylthiobenzenes and their sulfones and 63-93% for the sulfoxides. Co-extracted materials in the Florisil eluates that interfered with the ECD/GC quantitation were removed by partitioning the sulfoxides and sulfones into sulfuric acid and by thin layer chromatography on silica gel, using methylene chloride-hexane (50 + 50) as the developing solvent. Seven fish samples containing residues of chlorinated benzenes or polychlorinated biphenyls (PCBs) were examined for chlorinated methylthiobenzenes, methylthio-PCBs, and their oxidation products by matching GC retention times obtained with the EC detector and a flame photometric detector operated in the sulfur mode. These analytes were not found in the fish samples above a detection level equivalent to 0.02 ppm 2,4,5-trichloromethylthiobenzene.

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Determination of 34 pyrrolizidine alkaloids (PA) as contaminants in various plant extracts using UHPLC-ToF-HRMS

10.1055/s-0037-1608497 ◽

2017 ◽

Author(s):

A Schenk ◽

B Siewert ◽

S Toff ◽

J Drewe

Keyword(s):

Plant Extracts ◽

Pyrrolizidine Alkaloids

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Study on background interference in the process of determination of the ultra-low concentration of 226Ra in water by manganese fiber enrichment-scintillation cell radon measurement method

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-021-07678-z ◽

2021 ◽

Author(s):

S. P. Zhu ◽

Q. Tang ◽

S. K. Qiu ◽

C. Guo ◽

J. C. Liu ◽

...

Keyword(s):

Measurement Method ◽

Radon Measurement ◽

Low Concentration ◽

Background Interference ◽

Scintillation Cell

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Determination of Hexachlorobenzene and Mirex in Fatty Products

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/58.3.557 ◽

1975 ◽

Vol 58 (3) ◽

pp. 557-561

Author(s):

Rodney L Bong

Keyword(s):

Petroleum Ether ◽

Electron Capture ◽

Methylene Chloride ◽

Fats And Oils ◽

Fat Injection ◽

Liquid Chromatographic ◽

Ppm Level

Abstract A procedure is described for the isolation and cleanup of hexachlorobenzene (HCB) and mirex in fats and oils for gas-liquid chromatographic (GLC) analysis. The fat or oil is distributed on unactivated Florisil, and the HCB and mirex are eluted with acetonitrile. The pesticides are then partitioned into petroleum ether. Elution through activated Florisil with methylene chloride-hexane (20+80) is used for the final cleanup. HCB and mirex are then measured by GLC, using the appropriate electron capture conditions with a 15% OV-210 column for HCB and a 3% OV-101 column for mirex. The method demonstrates recoveries greater than 90% for HCB and mirex and allows screening at or below the 0.1 ppm level in fats with a 3 mg fat injection.

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