A method I'm working on is giving inconsistent injection repeatability. I've run it on 3 different days with 3 different results for RSD over 6 injections: 0.5%, 1.7% and 3.1%. I'm sure this inconsistency is from the method rather than instrument. The variance in area does not have a trend over the 6 injections, and I have not observed any carry-over issues. I've included some method parameters below. Any ideas? What components of the method are most likely to give rise to high RSD? Do you think the injector could have a hard time consistently drawing correct volumes of and IPA-based sample solvent? Thanks for any info! Column: 2.1x100mm BEH Shield Injection mode/volume: PLNO, 2 uL Loop size: 10uL Strong wash: 90% ACN (600uL) Weak wash: 10% ACN (600uL) Flow rate: 0.4 mL/min Mobile phase Buffer component: 12 mM phosphate pH 6.0 with 0.2%TEA; Organic component: 50/50 MeOH/ACN. 18 min run time. Analyte concentration: 0.4mg/mL For the stability of my primary analyte, I'm using a sample solvent that is 75% IPA.