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Trap Column (trap + column)

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Chemistry100%

Selected Abstracts

Determination of the active metabolites of sibutramine in rat serum using column-switching HPLC

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2008
So Young Um
Abstract A simple and direct analysis using column-switching HPLC method was developed and validated for the quantification of active metabolites of sibutramine, N -mono-desmethyl metabolite (metabolite 1, M1) and N -di-desmethyl metabolite (metabolite 2, M2) in the serum of rats administered sibutramine HCl (5.0 mg/kg, p.o.). Rat serum was directly injected onto the precolumn without sample prepreparation step following dilution with mobile phase A, i. e., methanol,ACN,20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (8.3:4.5:87.2 by volume). After the endogenous serum components were eluted to waste, the system was switched and the analytes were eluted to the trap column. Active metabolites M1 and M2 were then back-flushed to the analytical column for separation with mobile phase B, i. e., methanol,ACN,20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (35.8:19.2:45 by volume) and detected at 223 nm. The calibration curves of active metabolites M1 and M2 were linear in the range of 0.1,1.0 ,g/mL and 0.15,1.8 ,g/mL. This method was fully validated and shown to be specific, accurate (10.4,10.7% error), and precise (1.97,8.79% CV). This simple and rapid analytical method using column-switching appears to be useful for the pharmacokinetic study of active metabolites (M1 and M2) of sibutramine. [source]

Automation of nanoflow liquid chromatography-tandem mass spectrometry for proteome analysis by using a strong cation exchange trap column

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2007
Xiaogang Jiang
Abstract An approach was developed to automate sample introduction for nanoflow LC-MS/MS (,LC-MS/MS) analysis using a strong cation exchange (SCX) trap column. The system consisted of a 100,,m id×2,cm SCX trap column and a 75,,m id×12,cm C18 RP analytical column. During the sample loading step, the flow passing through the SCX trap column was directed to waste for loading a large volume of sample at high flow rate. Then the peptides bound on the SCX trap column were eluted onto the RP analytical column by a high salt buffer followed by RP chromatographic separation of the peptides at nanoliter flow rate. It was observed that higher performance of separation could be achieved with the system using SCX trap column than with the system using C18 trap column. The high proteomic coverage using this approach was demonstrated in the analysis of tryptic digest of BSA and yeast cell lysate. In addition, this system was also applied to two-dimensional separation of tryptic digest of human hepatocellular carcinoma cell line SMMC-7721 for large scale proteome analysis. This system was fully automated and required minimum changes on current ,LC-MS/MS system. This system represented a promising platform for routine proteome analysis. [source]