LCGC Europe-05-01-2016

LCGC Europe

Analysis of the Carotenoid Composition and Stability in Various Overripe Fruits by Comprehensive Two-Dimensional Liquid Chromatography

May 20, 2016

Features

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Carotenoids are a class of natural pigments, widely distributed in vegetables and fruits. A comprehensive LC×LC method, based on the use of a cyano and an octodecylsilica column, placed in the first and second dimension, respectively, was applied to evaluate carotenoid composition and stability in selected overripe fruits representing the waste generated by a local food market.

The Modulator in Comprehensive Two-Dimensional Liquid Chromatography

May 20, 2016

Columns

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The interface between the two separation dimensions is a key element of any comprehensive two‑dimensional liquid chromatography (LC×LC) system. LC×LC has typically been implemented by using one or more switching valves, equipped with either sampling loops or trap column(s). Temperature manipulation is a relatively unexplored yet promising route towards non-valve-based LC×LC. The fairly recent emergence of thermal modulation has provided a less conventional method for performing LC×LC separations. This article illustrates the variety of commonly used modulators, paying specific attention to focusing modulators.

Vol 29 No 5 LCGC Europe May 2016 Regular Issue PDF

May 01, 2016

Issue PDF

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Click the title above to open the LCGC Europe May 2016 regular issue, Vol 29, No 5, in an interactive PDF format.

Generic UHPLC Method for the Simultaneous Analysis of Compounds with a Wide Range of Polarities

April 19, 2016

Cover Story

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Appropriate analytical methods are required to evaluate the presence, metabolism, degradation, and removal of specific compounds in complex mixtures. There is an increasing demand to analyze samples with a wide range of polarities in a variety of applications, including environmental analysis, biomarker discovery, and proteomics. Multiple analyses on complementary columns are often needed to cover the separation of all compounds with a large difference in polarity. This article describes a generic method involving an ultrahigh-pressure liquid chromatography (UHPLC) system equipped with two external switching valves to connect hydrophilic interaction liquid chromatography (HILIC) and reversed-phase LC columns in series for the sequential analysis of polar and apolar compounds. The method was successfully applied to separate 32 pharmaceutical compounds with a wide range of polarities, which could be useful for analyzing pharmaceutical compounds in the environment.