Gas chromatography-mass spectrometry (GC-MS) combines two analytical tools to identify and measure the concentration of chemicals with low detection limits found in different sources, including food, consumer products, pharmaceuticals, fuels, the environment, and others. Gas chromatography is a method of separating volatile compounds in a mixture by passing them through a column in mobile stream of inert gas.  Due to differing adsorption affinities to the column material the compounds separate at different retention times.  The mass spectrometer is a very sensitive and specific detection system that correlates the amount of material eluting as a function of time.  The process involves ionization of the compound creating an ionized compound and partial ionized fragments of the material so the mass and fragmentation pattern of each peak in the chromatogram allows for the compound to be identified.  Often used in the fields of pharmaceutical development, forensic science and a broad range of research.

Gas chromatography is a method of separating volatile compounds in a mixture by passing them through a column in mobile stream of inert gas.  Due to differing adsorption affinities to the column material the compounds separate at different retention times.  The chromatogram allows for the compound to be identified via standard reference materials and quantified to the amount of each compound in the mixture. 

DSC measures the amount of heat required to keep the temperature of the sample the same as that of an inert reference material as the temperature is varied in a regular way. When the sample undergoes a phase change – e.g., melting, decomposition, structural change – more or less heat will be required to keep the sample at the same temperature as the reference. Both the temperature at which the change occurs and the amount of energy involved in the process can be determined. Often used in the fields of polymer chemistry, materials science and general purity analysis of materials.

The instrument measures the energy involved in exciting electrons of molecules by measuring the amount of light absorbed as a function of energy.  Commonly used for compound analysis as a function of light absorbed being proportional to the concentration of the substance in solution.  Used to characterize, identify and quantify compounds. 

The instrument is similar to a regular UltraViolet-Visible instrument but with an extended wavelength range.  It is capable of recording spectra of both liquid and solid samples.  Due to this capability materials that cannot be easily dissolved can be measured and analyzed.   

This instrument measures the light re-emitted by some molecules when they absorb light, a process called fluorescence. The instrument measures the fluorescence spectrum of such systems which is useful in studying the electronic properties of these molecules and is an extremely sensitive method of analysis as the emission intensity depends on concentration.

An XRD is an instrument for analyzing and measuring the structure of materials. When x-rays scatter off a crystalline solid, they do so at specific angles that depend on the structure of the crystal.  From this structural information can be obtained. The instrument records structural information from powdered materials that is specific to the material allowing for identification of solids.

An XRF spectrometer is an x-ray instrument used for routine, relatively non-destructive chemical analyses of rocks, minerals, sediments and fluids. When the inner electrons of an atom are excited, they emit x-rays of characteristic energies.  The instrument measures these fluorescent x-rays which allows the identity of the elements in a sample to be determined.  In some cases the quantitative composition can be found. Unique to this method is the nondestructive nature of the measurement so that valuable samples can be used, e.g. jewelry and art.

An NMR instrument allows the molecular structure of a material to be analyzed by observing and measuring the interaction of nuclear spins when placed in a powerful magnetic field. The idea behind nuclear magnetic resonance (NMR) is that some nuclei exist in specific nuclear spin states when an external magnetic field is applied.  NMR observes transitions between these spin states that are specific to the nuclei in question and its chemical environment, and therefore compound identification can be achieved.   Widely used in industry, medicine, biochemistry and physics. 

EPR is a technique used to study chemical species with unpaired electrons and allows understanding of organic and inorganic radicals, transition metal complexes, and some biomolecules. While electrons in molecules prefer to be paired, they cannot do so in odd-number electron systems and in some other cases such as free radicals.  These unpaired electrons can be excited to give spectra that are characteristic of the atom on which the unpaired electrons reside, the geometry around it, and its neighbors.  This makes the spectra useful for structure determination.  Free radicals occur in some foods; e.g. tea, coffee, bagels and beer, where EPR is a standard method for estimating shelf life.

This instrument is used for trace analysis – in parts per million range.  The solution is pulled into the instrument through a flame that is hot enough to decompose the compounds into their constituent atoms. Each atom absorbs light of specific energy so the amount of light from a source emitting at that energy that is absorbed by the atoms of interest in the flame can be related to the concentration in solution.

This instrument measures the energies involved in the vibration of the atoms in the molecule – i.e., the infrared spectrum.  Atoms in molecules vibrate with energies characteristic of the bonds and structural features of the molecule.  Measurement of these energies permits determination of molecular structure therefore the spectrum can be used for identification purposes. 

When a photon of light in the visible region interacts with a molecule, if it is not absorbed, it is scattered.  Some scattered photons transfer a bit of their energy to the molecule by exciting vibrations.  Raman spectra are like infrared spectra in that they show vibrational energies, but because the mechanism is different, they may show other vibrations.  Infrared spectra are complimentary to raman spectra allowing for structural determination and compound identification. Nondestructive technique often used for pigment identification of artwork.

This is an analytical technique that involves the separation of charged molecules within a narrow capillary tube under the influence of an electric field.  The method is performed in a liquid phase in the presence of a chromatographic stationary phase in a capillary column, under application of voltage longitudinally along the column.  Helpful bioanalytical technique for the separation of proteins.

Liquid Chromatography is a process of separating components in a liquid mixture. A liquid sample is injected into a stream of solvent (mobile phase) flowing through a column packed with a separation medium (stationary phase).  High performance systems can work at higher column pressures allowing for faster elution and better resolution.