GC-MS – Multimedia

QuEChERS involves an initial step when a few grams of the sample are extracted with acetonitrile followed by a clean-up step (with dispersive-SPE) used to remove, to a certain extent, unwanted matrix compound (such as pigments, sugars, organic acids). With QuEChERS, the final extract ends up with the pesticides in acetonitrile, which, being polar solvent, can be
problematic in GC-MS.

Analysis of Herbal powders or ‘churnas’ using an optimized GC-MS/MS method is described. As they have high amount of matrix co-extractives, they pose critical analytical problems. The purpose of this work was overcome the effect of the matrix and develop a reliable method.

Analysis of dithiocarbamate pesticides (DTCs) using an optimized GC-MS method is described. DTCs are not stable and cannot be extracted or analyzed directly. The purpose of this work was develop a reliable method for identification and quantification of residues.

The data summarized in this presentation dispels myths associated with the utilization of GC-MS for analytes which are critical for metabolomic studies. GC-HRT provides high quality, accurate mass data for:
-Spectral similarity searches (NIST, Wiley, etc.)
-Formula determination (fragment, molecular & adduct ions)
-GC-HRT is an indispensible tool for the analysis of complex biological samples.

Analyses of the M. truncatula extracts were performed, and data processing focused on qualitative analyses. This provided the opportunity for known analyte verification and unknown identification in a meaningful matrix and the demonstration of the key attributes and benefits of GC-HRT.

• To demonstrate a fully automated workflow for both liquid injection and headspace for GC and GC/MS.
• Automatically optimize analysis conditions and derivatization parameters.
• Automate standard preparation and derivatization procedures.
• Reduce analysts time involved in the analysis.
• Compare manual versus automated preparation of standards.

Purpose: An overview of the results of GC amenable compounds is given for EU 2013/39/EU
Methods: For the volatile compounds headspace GCMS was used; for the semivolatiles liquid liquid
extraction was applied followed by GCMSMS detection.
Results: The detection limits are calculated by standard deviation and there are some linearity examples. Not all compounds are listed in this poster, but a full list is available.

We introduce a new, innovative injector which allows conservation of helium carrier gas. While preserving the analytical GC column flow with helium, it maintains the septum purge and the split flows with another inert gas like nitrogen - even during the analytical run. The analytical performances of the injector are in line with those of the common split/splitless injector module

Purpose: Develop a rapid, sensitive method for determining amitraz and its metabolites in milk.
Methods: Samples were hydrolyzed in acidic condition and extracted with hexane. After derivativation, the samples were analyzed by GC-ECD or directly by GC-MS.
Results: The results show that GC-MS determination of amitraz and its metabolites is rapid and sensitive.

Purpose: Exploring the possibility to perform the sample preparation steps necessary for the derivatization of analytes in a fully automated and reliable way by means of the same robotic sampler used for sample injection into the gas chromatograph.
Methods: As an example of application we screened dairy products for melamine and its derivates presence via GC-MS/MS.
Results: The outcome are good and precise results that show how it is possible to reliably automate sample preparation opera