I am consistently observing blank interference at the NDBA retention time while analyzing small nitrosamines using LC-MS/MS. Currently, I am applying blank correction as a temporary measure.
How can I systematically troubleshoot and eliminate this blank interference? What could be the possible sources ?
Check contamination from filters, syringe, etc
Check you method step by step in reverse order: 1) LCMS instrument blank"; 2) final solvent blank in vial; 3) filtered final solvent blank in vial… and so on
Just curious, did you figure out, what is the structure or exact mass of the interfering compound?
The most common sources of contamination may come from solvents in the lab, instrument systems, consumables, etc. As RenatS mentioned, you can systematically check different blanks to identify the source of contamination. We have performed NDBA method development and detection many times, and NDBA contamination is very uncommon. We recommend thoroughly checking the brands of consumables and reagents you are using, as well as cleaning the injection needle and selecting an appropriate needle rinse solvent.
Just searching this site, you can see that NDBA contamination from plastic is quite common: