Fast chromatography definitions

Detector Time Constant This is a common cause of peak distortion, especially with fast chromatography on short columns. It occurs during the development of a method, but it is rarely the cause of trouble with an existing method. A peak with a retention time of one minute can easily have a standard deviation of under one second with today s high-performance columns. A setting of the detector time constant to one second, as is a commonly found default value, will definitely distort this peak. From the standpoint column performance, you should select a detector time constant of about 0.1 s for all but the slowest HPLC a q>lications. 

Introduction to fast performance liquid chromatography. Review Buffer preparation, Definitions of pH, Henderson-Hasselbalch equation, and Buffer calculations. 

Noniterative methods are fast, but they have clear limitations in their applicability because of the difficulties associated with correct definition of concentration windows and local rank. Their use is practically restricted to processes with sequentially evolving components like chromatography, the components of which fulfill the conditions required by Manne s theorems, to ensure a correct component resolution [22],... 

There are many definitions of fast gas chromatography (GC). For some, the definition of fast may be that we achieved the result in less time than we did yesterday . Others adhere strictly to rules such as the inherent speed of a given separation is best defined by the width of peaks and then seek to minimize this width for all peaks. In practical GC, the best definition of fast will be dependent on the analysis task at hand. The approach that an analyst accepts as a fast ... 

Size-exclusion chromatography (SEC) can - in principle - be used to measure both the amount of polymer formed and of unreacted monomer (Lousberg et al, 2002). However, other low-molar-mass materials present in the mixture may interfere with the measurement of the monomer. There is a definite trend towards fast separations by SEC (Pasch Kiltz, 2003 Popovici, 2004, 2005). Typical analysis times of Imin or less can be achieved for relatively simple separations (e.g. separation of monomer from polymer). This greatly increases the attractiveness of SEC for online measurements. 

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