[Routine method for identification of pesticide residues of triazine, carbamate, urea, and uracil type compounds by thin-layer chromatography]

Simultaneous determination of insecticides, acaricides and fungicides by thin-layer chromatography

A method is described for the determination of residual amounts of some insecticides, acaricides and fungicides in fresh and processed fruits. Optimum conditions were established for the extraction of eighteen pesticides, purification of the extracts by column chromatography and subsequent two-dimensional thin-layer chromatography on silica gel GF254 with cyclohexane-acetone (10:1) and light petroleum-benzene-ethanol (65:30:5) as solvents and with detection under UV light at 254 and 366 nm followed by a 0.1% solution of bromophenol blue.

Use of gas liquid chromatography/mass spectrometry for triazine herbicide residues analysis in forage and milk

Residual s-triazines were isolated from forage and milk samples by methanol/chloroform extraction followed by column purification. The evaporated extracts were dissolved in acetone and analysed by gas chromatography with NPD detection and mass spectrometry. The detection limits for both methods were found to be about 5 approximately 10 ng of each s-triazine. The selective ions of the 10 s-triazines investigated (simazine, atrazine, propazine, terbuthylazine, cyanazine, desmetryne, ametryne, prometryne, terbutryne and methoprotryne) were chosen on the basis of an electron impact mass spectrometry study of the s-triazine standards and the whole mass spectra are given. Special attention was paid to the fragmentation of cyanazine and the general cleavage pathways of the s-triazines under investigation.

[Identification of eleven urea herbicides by thin-layer and gas-liquid chromatography. I. Application to natural waters (author's transl)]

By the combined use of two-dimensional thin-layer chromatography and gas chromatography (with an electron capture detector), the authors succeeded in separating and identifying eleven urea herbicides at levels of up to 4 ppb. The method has been applied to natural surface waters.