Which GC instrument should I use for the analysis of pesticides in herbal tea? GC-MS/MS or GCxGC-TOFMS?

You may remember a while ago I posted a blog about the analysis of herbal tea using QuEChERS and GCxGC-TOFMS.   The LECO Pegasus GCxGC-TOFMS is a great instrument for analyzing complex samples because of the comprehensive chromatographic separation achieved (two columns with different selectivities).  The GCxGC-TOFMS also excels at non-target screening of compounds.  Lucky for us, we also have a Thermo TSQ 8000 GC-MS/MS in our lab to use.  The GC-MS/MS is also a great instrument for analyzing complex samples, like herbal tea, because of the selectivity afforded by the Selected Reaction Monitoring (SRM) transitions.  While the GC-MS/MS cannot do non-target screening like the TOFMS can, it is significantly more sensitive for targeted analysis.   My colleague Julie Kowalski and I set out to do a head to head comparison of the two instruments for the analysis of pesticides in herbal tea.  Check out the data and analysis conditions in my presentation that I gave at the recent EPA Region 6 Quality Assurance Conference in Dallas, TX.

Overall the instruments performed similarly, with only a few notable differences.  One of the major differences was that we could accurately quantify at the 10 ppb fortification level (5 pg on-column) on the GC-MS/MS where we could not get that sensitivity on the GCxGC-TOFMS system.

So which GC instrument should I choose for the TARGETED analysis of pesticides in herbal tea – the GC-MS/MS.  However, I couldn’t do this with the GC-MS/MS though.  So, in the end I am happy to have both instruments in the lab! Please let me know if you have any questions or want more info on this analysis.

Tags: , , ,

Leave a Reply


Restek Domestic Customer Service

Subject

Message

Your Full Name

Your Email

Company Name

Address

Spam Block (Please leave this blank)

all fields required

Thank you

Your message has been sent. We will be in touch shortly.

Message not sent

Sorry, your message could not be sent at this time. Please try again later, or contact Restek or your local Restek representative via phone.

www.restek.com/Contact-Us