Liquid–Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment

A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-μg/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid–liquid extraction and cleaned up using either a primary–secondary amine (PSA) cartridge or a C 18 cartridge. Extracts are then separated by gas chromatography and analyzed with tandem mass spectrometry. The method has been successfully tested by three cohorts of quantitative analysis students to determine the concentration of the insecticides spiked at 50 ng/mL in apple juice. Students’ average recoveries were between 78 and 121% using C 18 cartridges ( n = 30). Using PSA cartridges, average recoveries were between 47 and 121% ( n = 6). Overall, this laboratory experiment was successful in teaching analytical chemistry students about environmental exposure to insecticides and sample processing.