Liquid chromatography trapping

One example of normal-phase liquid chromatography coupled to gas chromatography is the determination of alkylated, oxygenated and nitrated polycyclic aromatic compounds (PACs) in urban air particulate extracts (97). Since such extracts are very complex, LC-GC is the best possible separation technique. A quartz microfibre filter retains the particulate material and supercritical fluid extraction (SPE) with CO2 and a toluene modifier extracts the organic components from the dust particles. The final extract is then dissolved in -hexane and analysed by NPLC. The transfer at 100 p.1 min of different fractions to the GC system by an on-column interface enabled many PACs to be detected by an ion-trap detector. A flame ionization detector (PID) and a 350 p.1 loop interface was used to quantify the identified compounds. The experimental conditions employed are shown in Table 13.2. 

Martinez Bueno MJM, Agiiera A, Gomez MJ, Hernando MD, Garcia JE, Fernandez-Alba AR (2007) Application of liquid chromatography/quadrupole-linear ion trap mass spectrometry and time-of-flight mass spectrometry to the determination of pharmaceuticals and related contaminants in wastewaters. Anal Chem 79 9372-9384... 

GC = gas chromatography ECD = electron capture detector EIA = enzyme-immunoassay GPC = gel permeation chromatography HPLC = high-performance liquid chromatography ITMS = ion trap mass spectrometer LSE = liquid solid extraction MS = mass spectrometry RSD = relative standard deviation SPE = solid phase extraction... 

Wang, H., Race, E.J., and Shrikhande, A.J., Characterization of anthocyanins in grape juices by ion trap liquid chromatography-mass spectrometry, J. Agric. Food Chem.,... 

A further extension of the DFG S19 method was achieved when polar analytes and those unsuitable for GC were determined by LC/MS or more preferably by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Triple-quadrupole MS/MS and ion trap MS" have become more affordable and acceptable in the recent past. These techniques provide multiple analyte methods by employing modes such as time segments, scan events or multiple injections. By improving the selectivity and sensitivity of detection after HPLC separation, the DFG S19 extraction and cleanup scheme can be applied to polar or high molecular weight analytes, and cleanup steps such as Si02 fractionation or even GPC become unnecessary. 

Debrauwer, L. Rathahao, E. Jouanin, I. Paris, A. Clodic, G. Molines, H. Convert, O. Fournier, F. Tabet, J. C. Investigation of the regio- and stereoselectivity of deoxygua-nosine linkage to deuterated 2-hydroxyestradiol by using liquid chromatography/ESI-ion trap mass spectrometry. J. Am. Soc. Mass Spectrom. 2003, 14, 364—372. 

Farre M, Perez S, Gajda-Schrantz K, Osorio V, Kantiani L, Ginebreda A, Barcelo D (2010) First determination of C60 and C70 fullerenes and N-methylfulleropyrrolidine C60 on the suspended material of wastewater effluents by liquid chromatography hybrid quadrupole linear ion trap tandem mass spectrometry. J Hydrol 383(l-2) 44-51... 

Jelic A, Petrovic M, Barcelo D (2009) Multi-residue method for trace level determination of pharmaceuticals in solid samples using pressurized liquid extraction followed by liquid chromatography/quadrupole-linear ion trap mass spectrometry. Talanta 80 363-371... 

Gheorghe A, Van Nuijs A, Pecceu B, Bervoets L, Jorens PG, Blust R, Neels H, Covaci A (2008) Analysis of cocaine and its principal metabolites in waste and surface water using solid-phase extraction and liquid chromatography-ion trap tandem mass spectrometry. Anal Bioanal Chem 391 1309-1319... 

Guerra P, Eljarrat E, Barcelo D (2008) Enantiomeric specific determination of hexabromo-cyclododecane by liquid chromatography-quadrupole linear ion trap mass spectrometry in sediment samples. J Chromatogr A 1203 81-87... 

Hogenboom A.C., Niessen W.M.A., and Brinkman U.A., 1998. Rapid target analysis of microcontaminanant in water by online single-short-column liquid chromatography combined with atomospheric pressure chemical ionization ion-trap mass spectrometry. J Chromatogr A 794 201. 

The mass-selective instability mode of operation permits the selection and trapping of all ions created over a specified period with subsequent ejection to the detector.26 Ions with different m/z values can be confined within the ion trap and scanned singly by application of voltages that destabilize the orbits of the ions and eject them to the detector. Ion trap instruments interface readily with liquid chromatography, ESI,15 and MALDI.27 The motions of the ions and the dampening gas (e.g., helium) concentrate around the middle of the ion trap, thereby diminishing ion loss through collisions with electrodes. 

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