Determination of Pesticides in Marine Sediments from Dakar Coast (Senegal) by Gas Chromatography-Tandem Mass Spectrometry (GC/MSMS)

Many aquatic products, especially coastal species consumed, are often in contact with sediments. Wastewater discharge channels often drain sediments that trap micropollutants. Sediments taken downstream of the Hann, Ngor and Soumbedioune drainage canals of the Dakar coast during the rainy season. These sediments are analysed by Gas Chromatography-Tandem Mass Spectrometry (GC/MSMS) finally to determine their degree of pesticide contamination. After separating the organic and water phases, we used QuECHERS and dSPE salts for extraction and purification. The analytes are separated by a temperature gradient of 55-330°C for 40 minutes. The results show that in these samples, 9 pesticides are present at levels higher than their respective quantitation limits. Atrazine, dichlorvos and terbutryne are more common in sediments. Their highest levels are 144.35, 284.462 and 509.998 µg, Kg-1, respectively. Contamination is greater at Hann and triazines pesticides are more present in different sediments and this distribution is generally asymmetrical with p-values below the 5% threshold.