Knowledge Centre

Automatic tuning of a GC-MS is essential for ensuring accurate and reliable results. It involves optimizing various instrument parameters to achieve optimal sensitivity, resolution and mass accuracy. A properly tuned GC-MS system provides confidence that the instrument is performing as expected, which allows for accurate analysis and interpretation of results

A TCD utilizes the differences in thermal conductivity. Thermal conductivity is the measure of how effectively a material transfers heat. Materials with a low thermal conductivity will act as an insulator by resisting heat flow whereas a material with a high thermal conductivity will act as a conductor, rapidly transferring heat. Gases have differing thermal conductivity value. To achieve maximum

When a sample contains unknown compounds, the best place to start is with a general GC-MS method. This method should include a slow oven ramp with a long hold at the end, this will ensure that all of the sample is eluted from the column. Then for the first injection run a blank, this should only contain the solvent.

There are a variety of libraries available for different applications. SCION Instruments offers various libraries including NIST, Wiley and Pfleger/Maurer/Weber (PMW) with customisable libraries and the ability to automatically search in multiple libraries. The most commonly used library is NIST. For the purpose of this technical note, NIST will be used as the example but the principles off all libraries

Reference Standards are samples of a known concentration of analyte(s). Standards can be used in the identification and confirmation of analytes. A series of standards at known concentrations can be used to produce a calibration curve which can be used for quantitative analysis.

Contamination is often detected by observing unusually high background signals in the mass spectra. This contamination can originate from either the GC or the MS. Analyzing the specific contaminants makes it possible to trace the source of the contaminants. Certain types of contaminants are more commonly associated with the GC, whilst others are typically linked to the MS.

A PTV injector is similar to a Split/Splitless (SSL) injector as it is capable of operating in both split and splitless modes but it can be programmed for isothermal or variable temperature operations. It is compatible with a range of open tubular capillary columns and can be used for large volume injections (LVI). Learn more about SCION’s injectors in our

There are a variety of libraries available for different applications. SCION Instruments offers various libraries including NIST, Wiley and Pfleger/Maurer/Weber (PMW) with customisable libraries and the ability to automatically search in multiple libraries. The most commonly used library is NIST. For the purpose of this technical note, NIST will be used as the example but the principles off all libraries

When setting out to analyze a sample from a complex sample matrix such as soil it is important to understand what analytes you are targeting and how to prepare your sample so it is suitable for your analysis. A common scope for analysis is to determine the quantity of semi volatile organics (SVOCs) in soil samples by gas chromatography (GC).

Volatile organic compounds (VOCs) are organic compounds which volatilize at lower temperatures e.g. limonene, ethanol and formaldehyde. Semi-volatile organic compounds (SVOCs) are organic compounds which tend to be solid or liquid at lower temperatures e.g. pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). SVOCs and VOCs are compounds commonly tested for and monitored by the analysis of environmental samples