A Device for the Simultaneous Cooling of the Fiber and the Evaporated Sample in the Determination of Pesticides from Soil Samples Using Fiber Headspace Solid-Phase Microextraction

Pesticides are used to control agricultural and industrial pests, and even combat diseases such as malaria, posing a serious threat to public health and many aspects of life. Therefore, identification, extraction, and preconcentration play a crucial role in the determination and measurement of these compounds. The cooled-heated device headspace solid-phase microextraction technique provides preconcentration of volatile and semi-volatile compounds. The aim of this research is to design and fabricate a new device for the simultaneous cooling of the fiber and evaporated sample and extracting pesticides. The innovative technique was evaluated by the extraction and gas chromatography mass spectrometry determination of chlorpyrifos, deltamethrin, fenvalerate and cypermethrin in soil samples. Optimization of the effective extraction parameters was carried out by the simplex method. Under the optimized conditions (i.e., cold and heat temperature of –10 and 70°C, water addition of 20 µL, and extraction time of 15 min), relative standard deviations of 3.94 to 6.51% were obtained of the studied compounds in five replicated analyses. The prepared fiber was stable and could be used several times without any significant change in its efficiency.