To any users with a 6470QQQ with an Agilent Jet stream source, I am running PFAS with an ICAL range of 0.1ng/mL up to 50ng/mL. My calibration curves pass fine, however for the lower standards, my % accuracy against the ICAL are fairly low 60-70% for levels 1 and 2, then climb to 80-100% for the top 7 points. My question has to do with the Sheath gas flow. Since it seems to be my lower cal points that are suffering, how does the sheath gas flow affect the low end? Lower flow better? Or is a higher flow better? Currently we are running Gas temp at 230C; Gas flow at 6 L/min; nebulizer at 20psi; sheath gas temp at 355C; and sheath gas flow at 10 L/min. Just curious what others are seeing/doing.

Thanks for input.