Liquid chromatography mass analyzers

A liquid chromatography-mass spectrometry (LC-MS) method that can quantitatively analyze urinar y normal and modified nucleosides in less than 30 min with a good resolution and sufficient sensitivity has been developed. Nineteen kinds of normal and modified nucleosides were determined in urine samples from 10 healthy persons and 18 breast cancer patients. Compounds were separ ated on a reverse phase Kromasil C18 column (2.1 mm I.D.) by isocratic elution mode using 20 mg/1 ammonium acetate - acetonitrile (97 3 % v/v) at 200 p.l/min. A higher sensitivity was obtained in positive atmospheric pressure chemical ionization mode APCI(-i-). 

C. Soler, B. Hamilton, A. Furey, K. J. James, J. Manes, and Y. Pico. Comparison of Four Mass Analyzers for Determining Carbosulfan and Its Metabolites in Citrus by Liquid Chromatography/Mass Spectrometry. Rapid Commun. Mass Spectrom., 20(2006) 2151-2164. 

A Simple and Rapid Assay for Analyzing Residues of Carbamate Insecticides in Vegetables and Fruits Hot Water Extraction Followed by Liquid Chromatography-Mass Spectrometry (from Bogialli et ah, 2004)... 

Of particular note is liquid chromatography/mass spectrometry (LC/MS) detection. LC/M S technology is a critical technique for DMPK studies due to its ability to analyze samples with very high sensitivity and specificity particularly within complex mixtures. It is not uncommon to find LC/MS based sample analysis residing within its own functional department due to the specialized facility requirements and technical skills of the operators. Additionally with LC/MS instrumentation becoming lower cost and simpler to operate, they are also becoming a workhorse... 

Although less expensive than liquid chromatography-mass spectrometry, confirmation by gas chromatography-mass spectrometry (492, 512) is applicable only to the volatile leuco forms and not to chromatic forms of the dyes. The reduced leuco forms of triphenylmethane dyes are volatile and thermally stable enough to be analyzed by gas chromatography-mass spectrometry (492, 512). 

Crescenzi, C., A. Di Corcia, E. Guerriero, and R. Samperi (1997). Development of a multiresidue method for analyzing pesticide traces in water based on solid-phase extraction and electrospray liquid chromatography mass spectrometry. Environ. Sci. Technol., 31 479 188. 

Bogialli, S., R. Curini, A. Di Corcia, M. Nazzari, and D. Tamburo. 2004. A simple and rapid assay for analyzing residues of carbamate insecticides in vegetables and fruits Hot water extraction followed by liquid chromatography-mass spectrometry. Agric. Food Chem. S2 665-671. 

Many approaches have been used to form ions, both in high-vacuum and near-atmospheric pressure conditions. Electron ionization (El) and chemical ionization (Cl) are ionization techniques used when gas phase molecules can be introduced directly into the analyzer from a gas chromatograph. In other analyses, such as high-performance liquid chromatography-mass spectrometry (HPLC-MS),... 

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