UC Davis

Conventional magnetic effervescent tablet has many drawbacks, such as not practicable for field processing, rapid moisture absorption, and poor tablet storage characteristics. Herein, we developed a novel magnetic effervescent tablet containing ionic liquid microextraction (MET-ILM) for determination of pyrethroids in dairy milk. It contains only Na₂CO₃ as an alkali source (no acidic source) in the Fe₃O₄ magnetic tablet; the CO₂-forming reaction is initiated in the acidic solution containing the analytes, and thus the prepared tablet can be stored for long time periods without deterioration. The combined action of extractant and sorbent vastly increase the extraction efficiency. The optimized procedure consisted of an effervescent tablet, 2:1 HCl:Na₂CO₃, and 60 μL [C₆MIM]PF₆ as extraction solvent. The LODs for five pyrethroids were 0.024-0.075 μg kg^-1 with recoveries of 78.3-101.8%. The RSDs were <4.8% and <6.3% for intra- and inter-day precisions. Overall, the method is very feasible for use in the field.