In this study, the QSight LC-MS/MS system was used to evaluate the potential of eliminating sample preparation for trace level pesticide analysis in a complex sample such as wine. We injected undiluted red and white wine samples into the mass spectrometer and studied reproducibility in analysis of the spiked pesticides over 200 injections. The instrument showed excellent reproducibility with minimal signal drift during the duration of the study (over a week), confirming the robustness of the QSight mass spectrometer.