Gas chromatography-high resolution mass spectrometry

Gas chromatography-high resolution mass spectrometry (GC-HRMS) 

In high resolution mass spectrometry a mixed spectrum of an internal standard, normally perfluorkerosene, and of the sample is taken. Using the known masses of the internal standard, the accurate mass values of the sample ions are calculated. Their elemental compositions can then be determined by searching for the best fit of combinations of atomic mass 

The peak matching technique [42] is the other frequently used method for making accurate mass measurements. It utilises the relationship between the ratio of the accelerating voltages required to focus a reference mass and a sample ibri at the same point on the detector, and the ratio of the masses, i.e. 

When an unknown compound requires identification, if it is easily purified, it would be introduced on a direct insertion probe and accurate measurements made by peak matching or computer scan. However GC-HRMS is necessary when the unknown is a component of a complex mixture. In HRMS the resolution and scan speed limit the accuracy of mass measurement. Sufficient samples need to be taken by the computer recording system across each ion peak to establish good peak shapes and hence accurate peak centres. The duration of a GC peak in the source can be too short to allow a complete mass scan while satisfying the required statistical conditions. The usual solution is to limit the mass scan. 

The application of GC-HRMS to the SIM technique (see Selected ion monitoring, p. 25) has the advantage of increasing specificity when handling multicomponent mixtures, but suffers from decreased sensitivity and the requirement for more costly equipment. Several examples are cited in later sections. 

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Leng G, Gries W (2005) Simultaneous determination of pyrethroid and pyrethrin metabolites in human urine by gas chromatography-high resolution mass spectrometry. J Chromarogr B 814 285-294... 

Kido et al. [6] determined basic organic compounds such as quinoline, acridine, aza-fluorene, and their N-oxides in marine sediments found in an industrial area. The sediments were extracted with benzene by using a continuous extractor for 12h. Hydrochloric acid solution (IN) was added to the benzene extracts, and the mixture was shaken for 5min the acid layer separated from the benzene layer was made alkaline by the addition of sodium hydroxide, and the alkaline aqueous solution was extracted with diethyl ether the ether extracts were then dehydrated with anhydrous sodium sulphate and concentrated with a Kuderna-Danish evaporator. The concentrations were separated and analysed by gas chromatography-mass spectrometry and gas chromatography high-resolution mass spectrometry. 

Alaee M, Sergeant DB, Ikonomou MG, et al. 2001. A gas chromatography/high-resolution mass spectrometry (GC/HRMS) method for determination of polybrominated diphenyl ethers in fish. Chemosphere 44(6) 1489-1895. 

Cai, Z., V. Ramanujam, D. Giblin, M. Gross, and R. Spalding (1993). Determination of atrazine in water at low- and sub-parts-per-tril-lion levels by using solid-phase extraction and gas chromatography/high-resolution mass spectrometry. Anal. Chem., 65(1) 21-26. 

Ferrario J, Byme C, McDaniel D, et al. 1996. Determination of 2,3,7,8,-chlorine substituted dibenzo-p-dioxins and furans at the part per trillion level in United States beef fat using high resolution gas chromatography/high resolution mass spectrometry. Anal Chem 68 647-652. 

Smith RM, O Keefe PW, Hilker DR, et al. 1986a. Determination of picogram per cubic meter concentrations of tetra- and pentachlorinated dibenzofurans and dibenzo-p-dioxins in indoor air by high-resolution gas chromatography/high-resolution mass spectrometry. Anal Chem 58 2414-2420. 

Gaskell, S. J., and Pike, A. W. (1978). Gas chromatography-high resolution mass spectrometry in the analysis of steroids in physiological fluids. In Quantitative Mass Spectrometry in Life Sciences (A. P. De Leenheer, R. R. Roncucci, and C. Van Peteghem, eds.), Vol. 2, pp. 181-189. Elsevier, Amsterdam. 

GC/HRMS Gas Chromatography/High Resolution Mass Spectrometry... 

PCDTs and PCTAs behave similarly to PCDDs and PCDFs. The exact value of the Ml ion of TeCDTs is 319.8788 and that of TeCDDs 319.8965. An MS response of about 20,000 in high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) is needed for a unique distinction between them. Separation can be achieved based on the longer retention times of the congeneric PCDTs compared to PCDDs in non-polar SE-30 and DB-5 type columns. 

Pouwels, A.D. Eijkel, G.B. Boon, J.J. Curie-point pyrolysis-capillary gas chromatography-high resolution mass spectrometry of microcrystalline cellulose. J. Anal. Appl. Pyrolysis 1989, 14, 237-280. 

Jonsson, S., Uusitalo, T., van Bavel, B., Gustafsson, I.-B., and Lindstrom, G. (2006). Determination of 2,4,6-trichloroanisole and 2,4,6-tribromoanisole on ngL-1 to pgL 1 levels in wine by solid-phase microextraction and gas chromatography-high-resolution mass spectrometry, /. Chromatogr. A, 1111,71-75. 

Van Rhijn, J. A., Traag, W. A., van de Spreng, P. F., and Tuinstra, L. G. M. Th., Simultaneous determination of planar chlorobiphenyls and polychlorinated dibenzo-p-dioxins and -furans in Dutch milk using isotope dilution and gas chromatography-high-resolution mass spectrometry, J. Chromatogr., 630, 297-306, 1993. 

High resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) also allows improving LODs. An example is PBDE determination in air, dust, and clothes dryer lint samples using this technique (Toms et al. 2009 Schecter et al. 2009). When C-labeled internal standards are added, analysis can be carried out by the isotope dilution technique. For example, PBDEs were analyzed in house indoor dust of different countries by GC/isotope dilution-HRMS (Sjodin et al. 2008). When volatiles are analyzed, another possibility is to use multidimensional GC/MS-olfactometry in a system equipped with a non-polar precolumn and polar column in series. This system was used to determine VOCs from swine barn particulate matter (Cai et al. 2006). 

U.S. Environmental Protection Agency, 1997b. Toxic Polychlorinated Biphenyls by Isotope Dilution High Resolution Gas Chromatography/High Resolution Mass Spectrometry. Office of Science and Technol. Washington DC., 62 pp. 

US EPA (1998) Method 8290A, Polychlorinated Dibenzodioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS)... 

Taguchi V (1994), The Determination of N-Nitrosodi-methylamine (NDMA) in Water by Gas Chromatography-High Resolution Mass Spectrometry (GC-HRMS), Environment Ontario (Canada), Laboratory Services Branch, QuaUty Management Office, Ontario Method catalogue code NDMA-E3291A (originally approved February 19, 1993 revised and approved April 7, 1994). 

Real-Time Gas Chromatography-High Resolution Mass Spectrometry and Its Application to the Analysis of Physiological Fluids Adv. Mass Spectrom. Biochem. Med. 1 565-576 (1976) CA 85 59014r... 

T. Takasuga, K. Senthilkumar, T. Matsumura, K. Shiozaki, and S. Sakai, Isotope dilution analysis of polychlorinated biphenyls (PCBs) in transformer oil and global commercial PCB formulations by high resolution gas chromatography-high-resolution mass spectrometry, Chemosphere 62 (2006) 469-484. 

HIGH-RESOLUTION GAS CHROMATOGRAPHY-HIGH-RESOLUTION MASS SPECTROMETRY (HRGC-HRMS)... 

US EPA, 1997. EPA Method 1668. Toxic polychlorinated biphenyls by isotope dilution high resolution gas chromatography/high resolution mass spectrometry, March 1997. 

Schanzer, W., Delahaut, P, Geyer, H., et al. (1996) Long-term detection and identification of metandienone and stanozolol abuse in athletes by gas chromatography-high-resolution mass spectrometry. Journal of... 

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