Nanofibers mat as sampling module of direct analysis in real time mass spectrometry for sensitive and high-throughput screening of illegally adulterated sulfonylureas in antidiabetic health-care teas.

In this work, novel ionic liquid (IL) functionalized polyacrylonitrile nanofibers mat (IL/PAN-NFsM) was firstly prepared through thiol-ene "click" reaction and evaluated for the establishment of a sensitive and high-throughput screening method. Because of its excellent pre-separation efficiency, IL/PAN-NFsM can adsorb trace-level targets from complex sample matrix within tens of seconds by performing a solid-phase extraction (SPE) process, and then served as sampling modules of direct analysis real time mass spectrometry (DART-MS) without any additional processing. This means the target analytes concentrated on IL/PAN-NFsM were directly desorbed, ionized, and detected by DART-MS. To verify the feasibility of the proposed method, three illegal added synthetic drugs (gliclazide, glimepiride, and gliquidone) were screened in six types of antidiabetic health-care tea samples. The results indicated that the sensitivity is in the level of ng g, while total analysis time does not exceed 1.0 min per sample. Moreover, the stability expressed as relative standard deviation (RSD) varies from 1.7% to 17.3%. We proposed a new screening mode based on the direct combination of functionalized NFsM and DART-MS, which is expected to become a universal method in food safety analysis.