Problems with MTBSTFA derivatization in GC-MS

I've been trying to replicate aqueous extractions using MTBSTFA and running on the GC-MS (I've done this before and it had worked). My solvent blanks are clear however it seems whenever I add MTBSTFA there is a lot of contamination peaks (both in a standard test and in PB). Could this possibly be a column issue? It's fairly old and has been used with other derivatization agents. I've tried 3 different MTBSTFA reagents and acetonitriles as I initially thought that might be contributing but all the results have been the same.

Procedural blank (acetonitrile and MTBSTFA):

Sample (Glycine, acetonitrile, and MTBSTFA):

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