Gas chromatographic analysis of the content of the organochlorine pesticide lindane in some samples of agricultural products under primary and secondary cultivation in the same soil

Residual content of the organochlorine pesticide lindane in model samples of tomatoes, cucumbers and onions was investigated by gas chromatography. A solution of the pesticide was added to the soil, after which the data were grown twice in contaminated soil. Two methods of sample preparation were used in the analysis: according to GOST 30349 and similar sample preparation using liquid nitrogen at the stage of homogenization. It was found that the use of liquid nitrogen in sample preparation increases the degree of analyte extraction up to two times. For tomato and cucumber samples, it was found that for both primary and secondary cultivation, the residual amount of organochlorine pesticide increased with increasing concentration of pesticide at spraying. However, this is not characteristic of onion samples. In the latter case, lindane residues decrease with increasing concentration of the parent analyte. This behavior is characteristic of root crop samples, to which onions are not related. The residual content of lindane in different parts of tomato and cucumber plants differs: tomato accumulates the pesticide to a greater extent in the fruit and cucumber in the haulm. In secondary cultivation in contaminated soil, the residual amount of lindane did not exceed 12 % of the original amount. As a result, it was found that the most suitable plant for growing on lindane-contaminated soils is cucumber, as 80-90 % of lindane is accumulated in inedible roots of cucumber, and the fruit contains the least amount of the contaminant among all vegetables. Tomato is unsuitable for cultivation on contaminated soils, as the fruit accumulates a significant amount of lindane.