Typical solvents are hexane and iso-octane. More polar solvents like acetonitrile and toluene can be used, but you probably need to invest more time in the development of the injection method with these solvents. Another influence is also sample pre-treatment, e.g. in what solvent will your extract end up after the last step of the preparation procedure.
In gas chromatography, sample preparation is critical to obtain the right result. Choosing the right chemicals for your method and application will help you for a successful analysis. Avantor® offers a broad range of chemicals for sample preparation of gas chromatography, such as solvents for headspace, pesticide and organic substances trace analysis, MOSH/MOAH and other applications.
What solvents should you select for GC-MS analysis?
Why has the HEADSPACE solvent grade been created?
When a GC-HS method is being developed, parameters such as sample solvent, extraction temperature and time, sample volume and headspace volume are optimized. Because the composition and purity of a sample solvent have significant effects on the recovery and quality of chromatogram, we have developed solvents specifically for GC-HS applications. Their purity and handling specifications meet the requirements of European Pharmacopoeia (Ph. Eur.). This new GC-HS solvent line includes many common organic solvents such as dimethylsulphoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAC) and n-Methylpyrrolidone-2.
What kind of high-purity solvents can I choose for dioxin analysis?
Dioxin determination in food is mostly done by GC-MS using dichloromethane, n-Hexane or toluene for sample preparation. We offer these solvents in high purity Merck UniSolv® or VWR Chemicals SUPRA TRACE grade. Due to their high specifications these grades are perfect for dioxin analysis by GC-MS.
What is the most popular solvent for dissolving a sample prior to injection on GC/MSD, especially for pesticide analysis?
It depends on the pesticides you want to analyze, and also on the matrix from where the pesticides are being extracted. Ethyl acetate or acetonitrile can be good solvents for this purpose. Generally modified QuEChERS methods prefer to use EA or ACN. These solvents can extract most of the pesticides present in a matrix, but there are still some matrices that need a different approach.
Be careful with acetonitrile in QuEChERS because this solvent is not really compatible with some compounds. In those cases you're better off using a polar solvent with solvent exchange into dichloromethane or hexane. Solvent selection also depends on many factors like solubility and polarity. Due to the high temperatures used in GC-MS, vapor generated from solvent after injecting a sample also plays an important role.