Detecting pyrethroid pesticide residues in cocoa products using laser induced breakdown spectroscopy

One of the main problems in cocoa products is the contamination of pesticide residues, especially pyrethroid pesticides. Therefore, a rapid and accurate detection of pyrethroid group pesticides is critically important to maintain the quality of fermented cocoa products. Conventional chemical methods to detect pesticide residues require complicated and time-consuming sample preparation. Therefore, it is necessary to develop new methods that are faster and easier. Laser-induced breakdown spectroscopy (LIBS) has been proven to be used to detect residual content pesticides in some food products. Testing of pyrethroid pesticide residues on fermented cocoa products using LIBS is possible because pyrethroid has several specific halogen elements that do not exist in fermented cocoa products that can be measured through LIBS. We report detection of cypermethrin (a synthetic pyrethroid pesticide) residue as low as 1wt.% using LIBS spectral line of chlorine at 837.6 nm.