Automated Sample Preparation and GC/Q-TOF for Metabolomics
Posted on September 30th, 2014
As the bookings come in for our Metabolomics Workshop in early November we have been working on automating a number of essential derivatisation and extraction techniques using our GERSTEL MultiPurpose Samplers.
These will be used to illustrate how sample preparation can be fully automated and to generate extracts that we can analyse using the Agilent 7200 GC/Q-TOF (the second part of the workshop).
The first prep method we have automated is the Folch extraction, a widely used method for extracting lipids from animal tissue. The automation of this method utilised both the agitating and centrifugation capabilities of our new CF200 Centrifuge. Initially we weighed 50mg of homogenised tissue sample into a 2mL vial and from then on the process was automated. After using the MPS syringe to add 1mL of the 2:1 chloroform:methanol mix, the vials were transferred to the centrifuge where it was vortexed and then centrifuged. The supernatant was transferred to a second vial and an aqueous aliquot was added to this. After further vortexing and centrifugation, an aliquot was taken from the bottom layer for analysis using the adjustable sampling height of the MPS autosampler.
The second method we have automated on a dual headed autosampler and are a fatty acid methyl ester derivatisation and extraction. The method required only 5mg of the test sample (dried herbs) which were weighed out into a 2mL vial. The process from here on was automated. An aliquot of methanolic chloride was added by the 1mL syringe to the vial containing the test sample, and this was transported to the heated agitator, where it was agitated for 15 minutes at 70°C to enable the methylation to take place. The reacted material was transported by the autosampler back to cool before the extraction solvents were added with the 1mL syringe and allowed to sit for 5 minutes. The derivatised fatty acids partitioned into the top layer and the second syringe (10µL) was programmed to take 10µL of this layer and using the cold injection system (CIS), set to solvent vent mode, the entire aliquot was introduced to the GC.
We are currently working on the Fiehn Extraction and plan to have this working in good time for the Workshops.
Our workshops are hands-on events, so places are limited. If you would like to reserve some places, please contact us now on +44 (0)1223 279210 or email us on firstname.lastname@example.org.