LC/MS/MS high-speed, high-resolution analysis methods with columns packed with particles of 2 μm or less are often used for analysis of drugs in human blood plasma. The small particle columns produce dispersion that is even less than that obtained with conventional columns (5 μm particle size), so peaks are taller, thereby enabling quantitation at even higher sensitivity. While this high-sensitivity analysis has become possible, the effect of autosampler carryover on high-sensitivity LC/ MS/MS analysis has become a problem. In Application News No. L425, we evaluated the performance of the Nexera SIL-30AC autosampler in the analysis of reserpine in human plasma, and reported its low carryover performance. In addition to the high potential of the SIL-30AC, we believe that rinsing with its powerful and sophisticated multi-solvent configuration was very effective. Here, we report on the effectiveness of the rinse method reported in Application News No. L425, and demonstrate its effectiveness as a rinse method applicable to measurement of a wide range of drugs in plasma.