We present two new methods for purifying dinosterol (4a,23,24-trimethyl-5a-cholest-22E-en-3b-ol) from sediments for the purpose of hydrogen isotope analysis via gas chromatography–isotope ratio mass spectrometry (GC–IRMS). The first method uses reversed phase-high performance liquid chromatography (RP-HPLC) to purify dinosterol from structurally similar 4a-methyl sterols that co-elute on GC ana...

A novel fast high-performance liquid chromatography (HPLC) method coupled with diode array detection (DAD) and time-of-flight mass spectrometry (TOF/MS) was developed for qualitative and quantitative analysis of Radix Astragali products. The potential of fast HPLC on 1.8-microm particles was compared with the performance of HPLC on conventional 5-microm particles columns. Significant advantages...

BACKGROUND Although high-performance liquid chromatography (HPLC) is the commonly used method for the analysis of retinol in biological samples, simple and rapid test kits are available. OBJECTIVES This study compared a rapid test kit (ICHECK Fluoro®) to HPLC for the assessment of serum retinol concentrations. METHODS For the analysis by HPLC, sample preparation included standard deproteini...

In this article, we describe a fast and specific method to measure 5FU with HPLC tandem-mass spectrometry. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled 5FU (1,3-15N2-5FU) was used as an internal standard. 5FU was measured within a single analytical run of 16 min with a l...

In this review article determines the different analytical methods for quantitative establishment of Erlotinib by using HPLC, HPLCMS, HPLC-UV, LC-MS/MS. Pharmaceutical method development requires valid procedures and qualitative analysis in Pharmaceuticals dosage formulations human serum. This assessment explains that superiority HPLC/LC-MS reviewed is based on drugs formulations, (API), biolog...

early in this study, an α-amylase from bacillus megaterium who (bmw) was isolated from hot springs of ramsar (north of iran), and its gene was cloned in e.coli. based on its conserved sequence regions and substrate specificity, it was classified as intermediary group enzymes with the specificity of oligo-1,6-glucosidase and neopullulanase subfamilies. in the sixth conserved region (83-qvngiwmmp...

weichang’an (wca) pill, a traditional chinese patent medicine consisting of ten chinese medicinal herbs, has been used to treat irritable bowel syndrome and functional dyspepsia for several decades. in this study, twelve bioactive constituents in the methanol extract of wca were accurately identified since ms/ms fragmentation behavior of the references and the standards by using hplc-dad-esi-ms...