Practical Comparison of Different Approaches to Speed Up LC Separations
January 1st 2007This article describes and compares a number of approaches to increase the speed of liquid chromatographic separations. On a standard LC column, a gain of a factor two in the run time (from 10 to 5 minutes) was achieved by increasing the flow-rate two-fold. On a monolithic column, a column operated at high temperature (120 ?C) and a short column, flow-rates could be increased typically five-fold, resulting in run times in the order of 2 minutes. This was accompanied by a sometimes considerable loss in separation efficiency. A combination of a very short run time and unaffected separation efficiency was realized on a UPLC system, designed for use at higher pressure. By working at approximately 800 bar, the analytes could be well separated within 30 seconds.
Gas Chromatography–Time-of-Flight Mass Spectrometry in Food Analysis
January 1st 2007Gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOF-MS) offers unique solutions for various analytical applications including the analysis of food quality, authenticity and safety markers. This article provides a general overview of TOF-MS basic features, highlighting its advantages and limitations compared with GC using conventional mass analysers. Examples of recent results obtained for selected food contaminants and flavour components are described to illustrate the potential of this recently introduced technique.