UniSpray has a grounded probe, and a stainless steel pin which is held at high voltage. The liquid stream is converted into a nebulized spray and directed at the stainless steel target (Figure 1), which creates a fine spray of charged droplets that is directed at the ion inlet orifice of the mass spectrometer. The resulting ions are sampled by the first vacuum stage of the mass spectrometer. Increased ionization efficiency, is achieved due to the enhanced desolvation and droplet evaporation.
The Xevo TQ-XS, is a high performance tandem quadrupole instrument, which offers the ultimate in reliability, reproducibility, specificity, and sensitivity, making it ideal for the determination of trace compounds in complex matrices such as field crops or soil.
UltraPerformance Convergence Chromatography (UPC2) is a separation technique that uses carbon dioxide as the primary mobile phase, with a co-solvent such as acetonitrile or methanol to give similar selectivity as normal phase LC. MRM transitions, and MS parameters were optimized for the compounds considered. ACQUITY UPC2 Separation parameters, using the Trefoil AMY1, 2.5 µm Column, were optimized in order to resolve the chiral triazole fungicides with a run time of 7 minutes (Figure 2). After a QuEChERS extraction, followed by a solid phase cleanup using Oasis MCX, sample extracts and standards were analyzed using the established MS and UPC2 conditions, using either UniSpray or ESI modes.
When using UniSpray coupled with ACQUITY UPC2 and Xevo TQ-XS for the analysis of triazole fungicides solvent standards, a 4.4-fold increase in peak area, 1.4-fold increase in S/N, and a 1.8-fold improvement in reproducibility were observed when compared against ESI results.
