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Liquid chromatographic determination of glyphosate and aminomethylphosphonic acid residues in rapeseed with MS/MS detection or derivatization/fluorescence detection

100%

Kaczyński P., Łozowicka B.

Open Chemistry

2015

vol. 13

issue 1

Glyphosate and AMPA determinations in rapeseed extracts by (a) liquid chromatography with triple quadrupole MS detection (LC-MS/MS), or (b) liquid chromatography with post-column OPA derivatization and fluorescence detection (LC-FLD) were developed. Mean recoveries for glyphosate and AMPA were (a) 88.8–95.0% and 82.1–86.1%, and (b) 70.8–74.1% and 62.4–72.6%. RSD were below (a) 11% and (b) 22%. Correlation coefficients were above 0.997 for both methods. LOD were 0.01 mg kg-1 for (a) and 0.05 mg kg-1 for (b). Both methods are simple and efficient for routine analysis of glyphosate and AMPA in a fatty matrix.

Study of lipophilicity of alpha-asarone derivatives and their deterrent activity against the Colorado potato beetle

81%

Łozowicka B., Kaczyński P., Nawrot J.

Open Chemistry

2013

vol. 11

issue 12

2120-2133

Five positional isomers and thirty derivatives of alpha-asarone wereobtained as a bioactive set of substances, and their deterrent activity against the Colorado potato beetle was studied. The lipophilicity values of thirty-six compounds were determined by using experimental, chromatographic and theoretical methods. The logk w values for all compounds were determined by reversed-phase high-performance liquid chromatography using five different columns. The octan-1-ol/water partition coefficients values were determined experimentally as a measure of lipophilicity. For the purpose of comparison, theoretical lipophilic parameters for all compounds were calculated with the use of chemical programs. The experimental, chromatographic and calculated values were compared using linear regression analysis. The most significant correlations were found between the chromatographic lipophilicities using methanol/water for all tested columns and calculated values. It has been found that 13 compounds have the lowest lipophilicities, which correspond to deterrent activity. The presented results show that the computational method is useful for determining the lipophilicity of a series of homologues, but not for positional isomers. In addition, this study shows that determination of lipophilicity using HPLC with various stationary phases is practical and reasonable for all alpha-asarone derivatives. [...]

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2 Open Chemistry

1 2015

1 2013

2 Kaczyński P.

2 Łozowicka B.

1 Nawrot J.

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Liquid chromatographic determination of glyphosate and aminomethylphosphonic acid residues in rapeseed with MS/MS detection or derivatization/fluorescence detection

Study of lipophilicity of alpha-asarone derivatives and their deterrent activity against the Colorado potato beetle