Liquid chromatography-mass resin

For metabolite isolation, 1.5 liters of pooled urine were applied to a XAD-2 resin column first. The ethyl acetate extract obtained containing 85 % of the radioactivity was applied upon evaporation to semipreparative HPLC on a Zorbax RX C18 column (9.4 x 250 mm, 5 pm) using gradient elution. Fractions obtained were further separated by isocratic elution on the semipreparative column. The metabolite fractions obtained were finally purified by preparative thin-layer chromatography. Liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS analysis was applied to the isolated metabolite fractions for structure elucidation. 

XAD-7 resin as the column material. Additionally, procyanidins have been separated from sugars and other interfering phenolic compounds by SPE using Sephadex LH-20 as the sorbent (Prior et ah, 2001). SPE has also been used to isolate phytoestrogens - including isoflavones, coumestans, and lignins from foods prior to further separation by liquid chromatography mass spectrometry (LC-MS) (Kuhnle et al, 2007). 

A solid-phase variant of the above synthesis utilized previously prepared MBHA-AB resin-bound 232 in reaction with sulfamyl chloride. The crude product from treatment of 233 with l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) for 48 h was analyzed by liquid chromatography-mass spectrometry (LC-MS), which indicated the presence of the desired product 234 as the major component (56%) of the mixture. A significant amount (26%) of unidentified material (mlz = Zil) was also present. As the focus of this work was preparation of sulfahydantoins, the effort to optimize the synthesis of 234 was not undertaken (Scheme 28) <2001JC0290>. 

Journal of Applied Polymer Science 72, No.7, 16th May 1999, p.913-25 HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY OF EPOXY RESINS... 

Synthesis of heterocycle 31" The resin, in a well of a 96-well reaction block, was treated with 100% formic acid (1.2 mL) for 18 hours at room temperature. After this time, the resin was filtered and the filtrate was concentrated under vacuum to yield heterocycle 31 as a film. The product was diluted with H20 MeCN (50 50), freeze-dried, and purity determined by liquid chromatography-mass spectrometry (LCMS) without further purification. 

Residues of isoxaflutole, RPA 202248 and RPA 203328 are extracted from surface water or groundwater on to an RP-102 resin solid-phase extraction (SPE) cartridge, then eluted with an acetonitrile-methanol solvent mixture. Residues are determined by liquid chromatography/tandem mass spectrometry (LC/MS/MS) on a Cg column. Quantitation of results is based on a comparison of the ratio of analyte response to isotopically labeled internal standard response versus analyte response to internal standard response for calibration standards. 

G.A. van der Doelen, K.J. van den Berg, J.J. Boon, N. Shibayama, E.R. de la Rie, W.J.L. Genuit, Analysis of fresh triterpenoid resins and aged triterpenoid varnishes by high performance liquid chromatography atmospheric pressure chemical ionisation (tandem) mass spectrometry, Journal of Chromatography A, 809, 21 37 (1998). 

In addition to GC/MS, high performance liquid chromatography (HPLC/MS) has been used to analyse natural resins in ancient samples, particularly for paint varnishes containing mastic and dammar resins [34]. A partial limitation of chromatographic techniques is that they do not permit the analysis of the polymeric fraction or insoluble fraction that may be present in the native resins or formed in the course of ageing. Techniques based on the direct introduction of the sample in the mass spectrometer such as direct temperature resolved mass spectrometry (DTMS), direct exposure mass spectrometry (DE-MS) and direct inlet mass spectrometry (DI-MS), and on analytical pyrolysis (Py-GC/MS), have been employed as complementary techniques to obtain preliminary information on the... 

Dimethylamine (109), putrescine (111), and spermidine (110), isolated from various insects (Table VIII), were obtained as p,p -nitrophenylazobenzoyl, p-phenylazobenzenesulfonyl, and I-dimethylaminonaphthalene-5-sulfonyl (dan-syl) derivatives and picrates or were detected by high-performance liquid chromatography (HPLC) using the ion-exchange resin (106,343). V,V-Dimethyl-3-phenylethylamine (131) from spiders of the genus Sclerobunus (Table VIII) has been identified by mass spectral comparison with a synthetic sample (117). 

Formyl-2-methylfuran was converted in 75% yield into derivative 319 by electrolytic methoxylation. A corresponding mixture of cis-diols (320) was treated with Dowex W-50 ion-exchange resin in methanol for four days, to afford 5-deoxy-3-C-(dimethoxymethyl)-DL-eryf/rro-4-pentulose dimethyl acetal (321). Reduction of this compound with lithium aluminum hydride or sodium borohydride gave a mixture of 5-deoxy-3-C-(dimethoxymethyl)pentoses, which was separated by column chromatography on silica gel, to give206 DL-streptose tetramethyl acetal (322) and the isomeric 5-deoxy-3-C-(dimethoxy-methyl)-DL-ribose dimethyl acetal 323 (hjxo ribo = 13 7). Detailed, combined gas-liquid chromatographic-mass spectrometric analysis of the compounds related to streptose (in the form of their trimethyl-silyl derivatives) has been described.207... 

Specific liquid chromatography methodologies and resins have been especially developed for the purpose this is a peculiar situation in the discipline of downstream bioprocessing. Today monoclonal antibodies and more largely immunoglobulins with all their derivatives represent by far the largest class of produced and purified protein in number and mass. 

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