This application note describes head-to-head comparison of GC-FID and SIFT-MS analyses of Class 2A and 2B residual solvents. The techniques perform similarly for linearity and repeatability, but SIFT-MS provides superior performance for accuracy and recovery. Furthermore, SIFT-MS provides greater than 11-fold increase in sample throughput and significantly reduces the time taken to report quantitative results (over six times faster for a full calibration set).