Solvent-free high-throughput analysis of herbicides in environmental water.

A high throughput, and eco-friendly method based on solid-phase microextraction (SPME) combined with direct analysis in real time mass spectrometry (DART-MS) was established for the determination of trace pollutants in water. A laboratory-made SPME device coated with a metal organic framework (MIL-100 (M)) was fabricated for the on-site enrichment of triazine herbicides in environmental water, and the device was directly subjected to DART ionization (<20 s) for high resolution MS. The interactions between the target analytes and sorbents were investigated to improve the SPME device targeting specific pollutants, as well as to improve the desorption and ionization processes with DART-MS. Other factors were also systematically studied to obtain the optimal conditions, including pH, salinity, extraction temperature, pressure at the Vapur® interface, linear rail moving speed, gas temperature, extraction time, and sample volume. The limit of detection of target compounds were 5.0-50.0 ng L-1 and the recoveries ranged from of 92.4%-125.7%.