A simple and rapid method has been developed for the extraction of impurities from illicit amphetamine samples using bonded-phase silica sorbents. The drug is dissolved in phosphate buffer (pH 7) and added to a C8 Bond Elut extraction column. The column is washed with water, and the impurities are then eluted with acetonitrile. The eluate is directly injected into the liquid chromatograph. This sample preparation technique has been compared with the traditional liquid-liquid extraction method. High-performance liquid chromatographic analysis of the impurities is carried out on a reversed-phase C18 column with an acetonitrile-water gradient as mobile phase. Peaks are monitored by UV detection at 220 and 254 nm. A series of seized amphetamine samples has been analysed, and the procedure gives detailed impurity patterns suitable for the comparison of samples. Compounds are identified by absorbance ratios (A220/A254).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0021-9673(85)80040-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Multiscale simulation of liquid chromatography: Effective diffusion in macro-mesoporous beds and the B-term of the plate height equation.
J Chromatogr A
December 2024
Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.
We performed multiscale simulations of analyte sorption and diffusion in hierarchical porosity models of monolithic silica columns for reversed-phase liquid chromatography to investigate how the mean mesopore size of the chromatographic bed and the analyte-specific interaction with the chromatographic interface influence the analyte diffusivity at various length scales. The reproduced experimental conditions comprised the retention of six analyte compounds of low to moderate solute polarity on a silica-based, endcapped, C stationary phase with water‒acetonitrile and water-methanol mobile phases whose elution strength was varied via the volumetric solvent ratio. Detailed information about the analyte-specific interfacial dynamics received from molecular dynamics simulations was incorporated through appropriate linker schemes into Brownian dynamics diffusion simulations in three hierarchical porosity models received from physical reconstructions of silica monoliths with a mean macropore size of 1.
View Article and Find Full Text PDFPreparation and chromatographic evaluation of 9-oxa-10-phosphophenanthrene 10-oxide bonded phenyl stationary phase and investigation of its retention mechanism through nuclear magnetic resonance spectroscopy.
Anal Chim Acta
July 2024
Institute of Drug Discovery Technology, Ningbo University, Ningbo, 315211, China; Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo, 315211, China. Electronic address:
Background: In reversed-phase liquid chromatography, the C alkyl bonded phase, as the primary stationary phase, is widely used in pharmaceutical and food analysis. The phenyl bonded phase often serves as a complementary choice to the C phase to enhance the separation performance of specific categories of compounds. However, both C and the currently available phenyl bonded phase chromatography columns show room for further optimization in improving the separation efficiency of specific compound classes, such as dihydroflavonoids.
View Article and Find Full Text PDFOrganic-solvent ditch overlap in reversed-phase liquid chromatography: A molecular dynamics simulation study in cylindrical 6-12 nm-diameter pores.
J Chromatogr A
July 2024
Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany.
Mass transport through the mesopore space of a reversed-phase liquid chromatography (RPLC) column depends on the properties of the chromatographic interface, particularly on the extent of the organic-solvent ditch that favors the analyte surface diffusivity. Through molecular dynamics simulations in cylindrical RPLC mesopore models with pore diameters between 6 and 12 nm we systematically trace the evolution of organic-solvent ditch overlap due to spatial confinement in the mesopore space of RPLC columns for small-molecule separations. Each pore model of a silica-based, endcapped, C-stationary phase is equilibrated with two mobile phases of comparable elution strength, namely 70/30 (v/v) water/acetonitrile and 60/40 (v/v) water/methanol, to consider the influence of the mobile-phase composition on the onset of organic-solvent ditch overlap.
View Article and Find Full Text PDFAssessment of the reproducibility of a C bonded phase based on ethylene-bridged hybrid organic/inorganic particles.
J Chromatogr A
February 2024
Waters Corporation, 34 Maple Street, Milford, MA 01757, USA.
The batch-to-batch reproducibility of an endcapped trifunctional C bonded phase based on ethylene-bridged hybrid particles was assessed using a modified version of a chromatographic test developed by Neue and coworkers. The test involves the isocratic separation of six compounds chosen to probe different characteristics of the stationary phase, including hydrophobicity, hydrogen bonding and cation-exchange. The assessment was based on results for a total of 471 batches manufactured and tested over a 19 year time span.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!