Mass spectroscopy (MS) is one of the most powerful and informative analytical tools available today. As a core service, Jordi Labs offers five different MS methods to allow the analysis of any sample type including solids, liquids, or gases. Jordi Labs has extensive expertise in the analysis and interpretation of mass spectral data and has some of the most advanced instrumentation available.
Methods available for MS analysis include:
- Desorption Gas Chromatography Mass Spectroscopy (DMS)
- Gas Chromatography Mass Spectroscopy (GCMS)
- Head Space Gas Chromatography Mass Spectroscopy (Headspace GCMS)
- Liquid Chromatography Mass Spectroscopy (LCMS)
- Pyrolysis Mass Spectroscopy (PYMS)
- Quadrupole Time of Flight – Liquid Chromatography Mass Spectroscopy (QTOF-LCMS)
Case Study: FTIR vs. PYMS
Objective
The objective of this study is to highlight the benefits and limitations of two analytical techniques, FTIR and PYMS.
Title Description File
Case Study: Beauty Product Comparison The objective of this study is to highlight the benefits and limitations of two analytical techniques, FTIR and PYMS.
Desorption Mass Spectroscopy (DMS)
This technique is excellent for solving problems related to off odors or for identifying plasticizers and other volatile sample components without the need for an extraction. The sample is placed into a quartz tube and dropped into a heating chamber at the desired temperature from 40-320ºC. Volatile components of the sample are desorbed and then transferred in the gas phase into a gas chromatography column. Components are then separated as a function of boiling point and interaction with the column stationary phase. They are then subjected to an electron impact (EI) mass spectrometry source. This results in a characteristic fragmentation pattern for each component. Comparison of the sample spectra to reference spectra for nearly two hundred thousand known compounds often allows for positive component identification. Only those components which can be desorbed from the sample can be analyzed by DMS.
Gas Chromatography Mass Spectroscopy (GCMS)
This is the method of choice for analysis of volatile components in liquid samples. A liquid sample is injected into the GC-MS using an auto-injector and then transferred in the gas phase into a gas chromatography column. Components are then separated as a function of boiling point and interaction with the column stationary phase. They are then subjected to an electron impact (EI) mass spectrometry source. The resulting characteristic fragmentation patterns are used for component identification. Comparison of the sample spectra to reference spectra for nearly two hundred thousand known compounds often allows for positive component identification. Creation of a calibration curve for known amounts of a reference material can be used for quantitation. A three point calibration is standard. This technique only provides information on volatile sample components.
Head Space Gas Chromatography Mass Spectroscopy (Headspace GCMS)
Headspace is the method of choice for analysis of volatile organic components in the presence of other less volatile components. Examples include fragrance analysis, determinations of organics present in biological matrices or analysis of VOCS in water samples. A portion of the sample is placed into a headspace sampling unit at a specified temperature. The gas above the sample is then injected onto a gas chromatography column. Components are separated as a function of temperature and interaction with the column stationary phase. They are then subjected to an electron impact (EI) mass spectrometry source. The resulting characteristic fragmentation patterns are used for component identification. Comparison of the sample spectra to reference spectra for nearly two hundred thousand known compounds often allows for positive component identification. Comparison with a calibration curve for known amounts of the reference material can then be used for quantitation. This technique only provides information on volatile sample components.
Liquid Chromatography Mass Spectroscopy (LCMS)
LCMS is one of the most versatile identification and quantification tools available. This technique is especially useful for additives and surfactant identification among others. It is also one of the most powerful quantitation methods providing sensitivity and specificity not available from other techniques. The sample is dissolved into a suitable solvent and then separated by liquid chromatography. Sample components are then passed into an electrospray ionization (ESI) or atmospheric chemical pressure ionization (APCI) source for analysis by mass spectrometry. Comparison with reference spectra from thousands of known compounds often allows for positive sample component identification. This technique can be applied successfully in many cases in which poor volatility of sample components prevents their detection by gas chromatographic methods. It also generally has higher sensitivity than GCMS methods.
Pyrolysis Mass Spectroscopy (PYMS)
The preeminent tool for polymer identification, PYMS is one of the most versatile methods available today for unknown identification. Jordi has extensive experience in PYMS analysis and has developed proprietary libraries covering hundreds of known polymer systems. Capabilities include evolved gas analysis (EGA) as well as PY-GCMS. In PYMS, the sample is placed into a sample cup and is subjected to a temperature program. Volatile sample components are desorbed followed by pyrolysis of less volatile materials. Pyrolysis can be performed using a temperature ramp resulting in separation of sample components based on thermal stability (EGA) or using column chromatography following cryogenic trapping of volatiles (PY-GCMS). The resulting materials are then analyzed by mass spectroscopy using an EI ionization source and compared to reference spectra for nearly two hundred thousand known compounds. Proprietary polymer and additive libraries have been developed by Jordi. Positive component identification is possible in many cases. This technique provides information on the polymer as well as additives in the polymer matrix. Evolved gas analysis can be used to examine thermo-oxadative stability of materials under a control atmosphere.
Quadrupole Time of Flight – Liquid Chromatography Mass Spectroscopy (QTOF-LCMS)
QTOF-LCMS is one of the most advanced methods available today for unknown identification for semi-volatile and ionizable components. This method provided all the advantages of conventional LCMS including specificity and sensitivity with the added benefits of high mass accuracy and MS/MS analysis. The QTOF instrumentation at Jordi can determine the mass of a compound to four decimal places with 2ppm mass accuracy. This allows for definitive identification of the elemental composition of an unknown in many cases. In addition, MS/MS analysis can be performed to further define the structure of the unknown based upon its fragmentation pattern. Proprietary polymer additive database have been developed by Jordi to aid in unknown identification from polymer systems.