Chromatography Forum

For the last two months I have been seeing toluene peaks in every run... blanks, CCV's and samples. It's always the same 6.64 uL with a response of 11649, peaking at 6.164. I have done a steam cleaning and replaced the column with no avail. Any ideas where this may be coming from? Could this be part of column bleed? We test cbd, thc, and hemp products here so I am not entirely sure where a toluene contaminant could be coming from. Does anyone have any thoughts?

Are these purge and trap, head space, or direct inject?

Different types if sample introduction can give different areas of contamination.

With toluene being volatile, is it used anywhere in the building?

I once worked with a lab that had trouble with 2-butanone contamination, they didn't use it anywhere in their facility. On the third day helping them an analyst went and opened a window in the lab because it was hot. I could smell something like 2-butanone and asked him what company was next door. It was a company that made office furniture, with a spray painting area vented to right outside their window. Contamination source found. Keeping it out was more difficult.

Agreed - follow your nose... it should eventually lead you to what smells like model airplane glue. Toluene is not put into as many things as it used to be, but it's still out there. It used to be in most paint products and is still found in fuels.

When talking about a MSD, someone could be walking through a greasy spot (from any car that leaks fuel - certain Fiat and Volkswagen models have issues with this) in the parking area and be tracking it into the lab on their shoes! It could also be coming from someone who works on a car at home and wears those shoes into the lab.

I have searched around to see what the buildings around us have, and there are no locations that would be working with toluene near us. After 2 days of searching for the source, (we do not have toluene in our lab or building), we found out that our triacetin wash was contaminated with toluene. I tested the bottle at different weights and sure enough there was a direct correlation. Not sure how, or why there would be toluene in analytical grade triacetin. Going to order a new bottle and hope to see that peak go away. Very frustrating as toluene in something we test for for I feel uneasy about eliminating hits on a regular basis. Also going to look into a different diluent.