Direct immersion solid-phase microextraction combined with ambient ionization tandem mass spectrometry to rapidly distinguish pesticides in serum for emergency diagnostics.

Despite the fact that carbamates and organophosphates cause acute poisoning via different mechanisms and require disparate management, they are indistinguishable by current clinical assays. Herein, direct immersion solid-phase microextraction (DI-SPME) plus thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS) was developed to discern them. Both pesticides spiked in human serum were extracted by SPME and analyzed by TD-ESI/MS/MS. This is a promising emergency care platform as rapid analyses could be done in tiny sample volumes with satisfactory recovery (89.46%-116.32%), precision (covariance <20%), sensitivity (LOD <0.1 μg/mL), turnaround time (<5 minutes), and linearity (R2 = 0.9827-0.9992) within 0.1-100 μg/mL.