Methods overview
- Gas Chromatography (GC)
- High-Performance Liquid Chromatography (HPLC)
- Ion Chromatography (IC)
- Mass Spectrometry (MS)
- Digestion systems
- Cation analysis
- Anion analysis
GC is a physico-chemical separation technique for the qualitative and quantitative analysis of substance mixtures, the components of which can be vaporized without decomposition.
GC Configuration | Applications |
Pyrolysis GC/MS | Characterization of polymers, copolymers, high-molecular organic substances, quality control of synthetic materials |
Headspace GC/MS | Highly volatile compounds in complex matrices (liquid or solid), e.g. solvents, aromatic substances, monomers |
Thermal desorption GC/MS |
Workplace measurements, analysis of hazardous substances, airborne contaminations |
Purge and Trap GC/MS | Trace analysis of volatile substances in liquid or solid samples, e.g. aromatic substances |
Solid-Phase Microextraction (SPME) GC/FID | Enrichment of analytes, e.g. substances from solid or semi-solid samples, trace analysis in liquid samples |
GC-MS / MS with Ion Trap and Quadrupole Technique | Mass spectroscopic identification of unknown substances, e.g. environmentally relevant pollutants and their degradation products, also for validating results |
GC with Thermal Conductivity Detector | Universal application, especially for gases |
GC with Flame ionization detector (FID) | Universal application, e.g. for triglycerides, hydrocarbons, fatty acids, solvents |
There are different sample injection systems like on-column, split/splitless, PTV (programmed temperature vaporizer).
HPLC is a physico-chemical separation technique for the qualitative and quantitative analysis of complex mixtures. In contrast to gas chromatography, which is a very good separation method for vaporizable substances, non-volatile substances can be analyzed using HPLC. Current HPLC developments with a higher sample flow rate, ever smaller sample volumes and improved resolution are called ultra high performance liquid chromatography (UHPLC).
UHPLC, HPLC and ion chromatography (IC) units with various detectors are available.
Detection | Applications |
LC-MS / MS | With electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), e.g. for the identification and quantification of unknown compounds, investigation of the metabolism of pharmaceuticals, the structural elucidation of compounds, sequencing of peptides |
Refraction index detector (RI) |
Universal application, e.g. for monosaccharides, disaccharides, organic acids |
UV/VIS detector |
e.g. for pharmaceutic active ingredients, food additives, vitamins |
Diode array detector (DAD) | Identification and characterization of compounds by means of UV/VIS-spectra |
Fluorescence detector (FLD) | e.g. for amino acids, polycyclic aromatic hydrocarbons (PAH) |
Light Scattering |
For non-volatile substances that cannot be detected in the UV or fluorescence detector |
Ion chromatography is a variant of liquid chromatography which allows the qualitative and quantitative analysis of ions (cations, anions, organic acids) according to various mechanisms (ion exchange, ion exclusion, ion pair formation). Fraunhofer IGB uses ion chromatography with suppressor technology as well as ion pair chromatography. For example, alkali and alkaline earth metals, anions and organic acids can be analyzed.
Detection | Applications |
Electrochemical Detector (ED)
|
For monosaccharides, polysaccharides, phenols, catecholamines, cyanides, hydroxylamines |
Conductivity Detector
|
For anions, cations, organic acids |
Exact molecular masses can be determined by MS where substances are ionized at an ion source. At the IGB different ionization / separation techniques are available: GC-MS/MS,
LC-MS/MS and MALDI-TOF-MS.
Equipment | Applications |
GC-MS/MS Ion Trap, Quadrupol |
For the MS identificaton of unknown substances, e. g. hazardous compounds and metabolites; for the confirmation of experimental data |
LC-MS/MS Electrospray ionization (ESI) and Atmospheric pressure - chemical ionization (APCI) |
e.g. for peptide sequencing, identification of metabolites, structural characterization |
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) | Inductively coupled plasma mass spectrometry (ICP-MS) is a robust, very sensitive mass spectrometric method of analysis in inorganic elemental analysis. Among other purposes, it is used for the trace analysis of heavy metals such as lead, cadmium, bismuth or rare earths. |
MALDI-TOF-MS | For the determination of molecular mass of high molecular weight natural and synthetic compounds, e.g. peptides and proteins |
A digestion procedure is a method of sample preparation for solids using various mineral acids with the aim of transferring the analyte into solution and then analyzing it with a spectroscopic technique.
In atomic emission spectrometry the atoms to be detected are excited by inductively coupled plasma (ICP), a gas ionized in the high-frequency field. The energy absorbed is emitted in the form of emission spectra. This method is employed in inorganic elemental analysis.
Inductively coupled plasma mass spectrometry (ICP-MS) is a robust, very sensitive mass spectrometric method of analysis in inorganic elemental analysis. Among other purposes, it is used for the trace analysis of heavy metals such as lead, cadmium, bismuth or rare earths.
Ion chromatography is a variant of liquid chromatography that permits the qualitative and quantitative analysis of ions on the basis of various separation mechanisms (ion exchange, ion exclusion, ion pair formation). At Fraunhofer IGB, ion chromatography is used with suppressor technology.
By TOC the total organic carbon content of a sample is determined by oxidation of organic compounds to carbondioxide (CO2). The TOC value is the difference between Total Carbon (TC) and Total Inorganic Carbon (TIC).