Chromatography mass spectrometry detection

GAS CHROMATOGRAPHY/MASS SPECTROMETRY DETECTION OF XENOBIOTICS IN ENVIRONMENTAL... 

Liu H, Sabus C, Carter GT, Du C, Avdeef A, Tischler M (2003) In vitro permeability of poorly aqueous soluble compounds using different solubilizers in the PAMPA assay with liquid chromatography/mass spectrometry detection. Pharm Res 20 1820-1826. 

Frias, S., M.A. Rodriquez, J.E. Conde, and J.P. Perez-Trujillo (2003). Optimization of a solid-phase microextraction procedure for the determination of triazines in water with gas chromatography-mass spectrometry detection. J. Chromatogr. A, 1007 127-135. 

Earina, L., Boido, E., Carrau, E, Delacassa, E. (2007). Determination of volatile phenols in red wines by dispersive liquid-liquid microextraction and gas chromatography-mass spectrometry detection. J. Chromatogr. A, 1157, 46-50. 

A Method Using Gas Chromatography - Mass Spectrometry Detection of Mycotoxins from Trichothecene Groups A and B... 

An interesting approach was developed by D Amico et al. (2008), in which they nsed an electronic nose sensor with a good sensitivity towards volatile organic compounds emitted by skin lesions from melanoma patients, and the method seems to be effective for identification of malignant lesions. The gas sensor nsed gas chromatography mass spectrometry detection and shows satisfactory accuracy. This approach does not use a biosensor bnt combines chemometric tools with a sensor that can be a favourable approach to detect a pattern in POC biomedical devices. 

ROLE OF COMPUTERS IN GAS CHROMATOGRAPHY-MASS SPECTROMETRY DETECTION, IDENTIFICATION, AND QUANTIFICATION IN DRUG METABOLISM RESEARCH... 

Serodio, P. and Nogueira, J.M.F. (2004) Multi-residue screening of endocrine disrupting chemicals in water samples by stir bar sorptive extraction gas chromatography mass spectrometry detection. Anal Chim. Acta, 517, 21—32. 

The ion spray liquid chromatography/mass spectrometry (LC-MS) interface coupled via a postsuppressor split with an ion chromatography (IC) has been used in the analysis of alcohol sulfates. The IC-MS readily produces the molecular weight while the tandem mass spectrometric detection IC-MS-MS provides structural information [305]. 

Vieno NM, Tuhkanen T, Kronberg L (2006) Analysis of neutral and basic pharmaceuticals in sewage treatment plants and in recipient rivers using solid phase extraction and liquid chromatography-tandem mass spectrometry detection. J Chromatogr A 1134 101-111... 

The active drug and metabolites can be detected from the urine by thin-layer chromatography, gas-liquid chromatography, or gas chromatography-mass spectrometry. However, assays are available only at specialized centers. Treatment of acute intoxication with mescaline is virtually identical to the treatment outlined for LSD intoxication. DOM-induced vasospasm responds well to intra-arterial tolazohne or sodium nitroprusside. Major life-threatening complications of hallucinogenic amphetamine derivatives include hyperthermia, hypertension, convulsions, cardiovascular collapse, and self-inflicted trauma. 

Table 5.2 Selected-reaction monitoring (SRM) transitions nsed for MS-MS detection of the pesticides studied in the systematic investigations on APCI-MS signal response dependence on eluent flow rate. Reprinted from J. Chro-matogr.. A, 937, Asperger, A., Efer, J., Koal, T. and Enge-wald, W., On the signal response of various pesticides in electrospray and atmospheric pressure chemical ionization depending on the flow rate of eluent applied in liquid chromatography-mass spectrometry , 65-72, Copyright (2001), with permission from Elsevier Science...

Table 5.8 Polypeptides detected during the LC-electrospray-MS analysis of the tryptic digest from / -lactoglobulin (/ILG). Reprinted from 7. Chromatogr., A, 763, Tnrnla, V. E., Bishop, R. T., Ricker, R. D. and de Haseth, J. A., Complete structnre elncidation of a globular protein by particle beam hqnid chromatography-Fourier transform infrared spectrometry and electrospray hqnid chromatography-mass spectrometry - Seqnence and conformation of / -lactoglobulin , 91-103, Copyright (1997), with permission from Elsevier Science...

Breithaupt, D.E., Wirt, U., and Bamedi, A., Differentiation between lutein monoester regioisomers and detection of lutein diesters from marigold flowers (Tagetes erecta L.) and several fruits by liquid chromatography-mass spectrometry, J. Agric. Food Chem. 50, 66, 2002. 

S. Alugupalli, L. Larsson, M. Slosarek, and M. Jare.sova, Application of gas chromatography-mass spectrometry for rapid detection of Mycobaaerimn. xenopi in drinking water, Appl. Environ. Microbiol. 5 3538 (1992). 

M. Slosarke, S. Alugupalli, J. Kaustova, L. Larsson, Rapid detection of Mycobater-ium kanasii in water by gas chromatography mass spectrometry, J. Microbiol. Methods 27 217 (1996). 

When pushed to the limit by overriding human health concerns, residue chemists have achieved detection limits of Ippt (Ingkg ) or even into the low ppqr (1 pg kg ) range. An example at the 1 ppt level is provided by methods for 2,3,7,8-tetrachlorodibenzodioxin (TCDD) in milk and TCDD in adipose tissue. Eor relatively clean matrices such as water and air, preconcentration on solid-phase adsorbents followed by GC or gas chromatography/mass spectrometry (GC/MS) can provide detection limits of 1 ng m and less for air (examples in Majewski and Capel ) and 1 ngL and less for water (examples in Larson et A summary of units of weight and concentration used to express residue data is given in Table 1. 

Liquid chromatography/mass spectrometry Lower limit of detection Limit of detection Limit of quantitation Florseshoe crab hemocyanin Liquid scintillation counting Matrix-assisted laser desorption/ ionization mass spectrometry m -Maleimidobenzoy 1-A -Hydroxysuccinimide 1 -Cyclohexyl-3-(2-Morptiolino-ethyl)carbodiimide rnetlio-/ -Toluenesulfonate (same as CDI)... 

The method for chloroacetanilide soil metabolites in water determines concentrations of ethanesulfonic acid (ESA) and oxanilic acid (OXA) metabolites of alachlor, acetochlor, and metolachlor in surface water and groundwater samples by direct aqueous injection LC/MS/MS. After injection, compounds are separated by reversed-phase HPLC and introduced into the mass spectrometer with a TurboIonSpray atmospheric pressure ionization (API) interface. Using direct aqueous injection without prior SPE and/or concentration minimizes losses and greatly simplifies the analytical procedure. Standard addition experiments can be used to check for matrix effects. With multiple-reaction monitoring in the negative electrospray ionization mode, LC/MS/MS provides superior specificity and sensitivity compared with conventional liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/ultraviolet detection (LC/UV), and the need for a confirmatory method is eliminated. In summary,... 

The need to understand the fate of pesticides in the environment has necessitated the development of analytical methods for the determination of residues in environmental media. Adoption of methods utilizing instrumentation such as gas chro-matography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), liquid chromatography/tandem mass spectrometry (LC/MS/MS), or enzyme-linked immunosorbent assay (ELISA) has allowed the detection of minute amounts of pesticides and their degradation products in environmental samples. Sample preparation techniques such as solid-phase extraction (SPE), accelerated solvent extraction (ASE), or solid-phase microextraction (SPME) have also been important in the development of more reliable and sensitive analytical methods. 

For method tryout, run a control sample and two fortifications from each site. One fortification should be done at the LOQ and the other at the highest expected residue level, perhaps 1000 x LOQ. If the recoveries are within the acceptable range of 70-120% and there are no interferences, proceed with the method validation. If interferences are present which prevent quantitation of the analyte, try additional cleanup steps with SPE or use a more selective detection method such as liquid chromatography/mass spectrometry (LC/MS). 

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