I operate a GCMS system with P&T and recently performed system maintenance. I use a standard autotune and then a manual tuning procedure for BFB instead of BFB autotune (because of the column I am using) in order to pass the tune evaluation. The manual tuning procedure works well except that the 50 ion in BFB hovers below and above the 15% threshold for relative abundance for that ion. An old application note says to lower the ratios of 131 and 219 to 69 in manual tune in order to achieve greater abundance of the 50 ion. I am slightly suspect of outdated application notes so I am reaching out on the forum. Cheers!