A high-throughput, ultrafast, and online three-phase electro-extraction method for analysis of trace level pharmaceuticals

Sample preparation is often reported as the main bottleneck of analytical processes. To meet the requirements of both high-throughput and high sensitivity, improved sample-preparation methods capable of fast analyte preconcentration are urgently needed. To this end, a new three-phase electroextraction (EE) method is presented that allows for ultrafast electroextraction hyphenated to flow-injection analysis mass spectrometry (FIA-MS). Four model compounds, i.e., propranolol, amitriptyline, bupivacaine, and oxeladin, were used to optimize and evaluate the method. Within only 30 s extraction time, enrichment factors (EF) of 105–569 and extraction recoveries (ER) of 10.2%–55.7% were achieved for these analytes, with limits of detection (LODs) ranging from 0.36 to 3.21 ng mL−1, good linear response function (R2 > 0.99), low relative standard deviation (0.6%–17.8%) and acceptable accuracy (73–112%). Finally, the optimized three-phase EE method was successfully applied to human urine and plasma samples. Our three-phase electroextraction method is simple to construct and offers ultrafast, online extraction of trace amounts of analytes from biological samples, and therefore has great potential for high-throughput analysis. [Display omitted] •Ultrafast analyte extraction, down to 30 s.•High enrichment factors of up to 569-fold.•Direct hyphenation to MS.•Simple extraction setup.•Limit of detection as low as 360 pg/mL.