Knowledge Centre

A detailed explanation of how to optimize splitless injection and why it benefits a lab. During a splitless injection the split valve is closed which minimizes the loss of sample and maximizes sensitivity. It is common to use a splitless injection for trace analysis.

There are many benefits to trying to reduce sample and solvent volumes used within your lab. Some of these benefits include cost, health and waste. There are alternative sample preparation techniques now widely available which can allow your lab to become more efficient, reduce sample preparation time and decrease the need for costly solvents and laboratory glassware and equipment.

Derivatization extraction is a technique in which an analyte is chemically modified into a product with a similar structure but improved analytical properties. It is important because it enhances detectability, particularly for polar compounds that are less volatile and more difficult to analyze using gas chromatography (GC). By converting functional groups such as N–H and O–H into less polar forms,

Purge and Trap is a sample preparation technique widely used in environmental laboratories for the analysis of volatile organic compounds (VOCs) in water, soil and other sample matrices. Purge and Trap is used in regulatory methods such as EPA 524, 624 and 8260. The EST Purge and Trap combined with the SCION Instruments’ 8300 or 8500 GCs provides a complete

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.