Magnetic effervescent tablets containing ionic liquids as a non-conventional extraction and dispersive agent for determination of pyrethroids in milk

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.