Chromatographic integrity

Maintenance of chromatographic integrity (concentration and distribution) tmeness... 

In HPLC-TLC coupling, the crucial aspect is the maintenance of the chromatographic integrity during the deposition process. The chromatogram is preserved after LC separation, and is available for further separation and/or investigation. LC-TLC coupling increases the separation efficiency, and allows detection modes which are incompatible with LC (e.g. spectroscopic techniques... 

Chromatographic Integration Methods, Second Edition by Norman Dyson, Dyson Instruments Ltd, UK... 

Inject the standard into the sample loop of the HPLC instrument and observe the output of the atomic fluorescence instrument on the chromatographic integrator. On elution of the first arsenic species, switch the mobile phase from 0.0001 M K2SO4 to 0.1 M K2SO4 (step gradient elution). 

Environmental Protection Agency. Problems with Chromatographic Integrators Process Measurements Review Industrial Environmental Research Laboratory Research Triangle Park, NC, 1979 Vol. 2, No. 1, p 45. 

This chapter describes the more commonly used methods of quantitation, with brief discussions on the theory. For more information on the use of computers and quantitation, see Braithwaite and Smith.10 An excellent account of chromatographic integration methods for peak identification, validation, and quantitation is provided in the text by Dyson.11... 

Dyson, N., Chromatographic Integration Methods. Royal Society of Chemistry, Cambridge, 1990. 

Dyson, N. (1998), Chromatographic Integration Methods, Second Edition, RSC Chromatography Monographs Series (Ekl. R.M. Smith), Royal Society of Chemistry, Cambridge, U.K. 

To achieve this whilst maintaining chromatographic integrity through the LC/MS interface was likened by Arpino 6 to an improbable love affair between a goldfish, symbolising the liquid LC mobile phase, and a parrot, symbolising the gas phase in MS (Fig. 5.1). 

With w = 4(7 it is possible to calculate N. Literature N. Dyson, Chromatographic Integration Methods. Royal Society of Chemistry, London, 2nd ed., 1998, p. 23. 

In an effort to speed up the rate of analysis, several researchers have experimented with gradient elution at flow rates that vastly exceed the optimum linear velocity predicted by the Van Deemter equation. Romanyshyn and co-workers have shown the ability to retain chromatographic integrity with ultrafast gradients (e.g., 1.5 mL/min on a 2 x 20-mm column) [84,85]. By direct comparison to isocratic methods, the authors further demonstrated... 

Earlier implementation of SFC-MS followed the evolution of both HPLC-MS and GC-MS interfaces [11,21,23-26], As the API interfaces of HPLC-MS became mainstream analytical techniques in recent decades, they were also quickly employed for SFC-MS [21,23,26-37], The atmospheric pressure chemical ionization (APCI) [27,33] and electrospray ionization (ESI) [36,37] sources are the most popular API interfaces for SFC-MS systems and allow for direct introduction of the effluent to the inlet of the mass spectrometer (Table 9.1). In some cases, the commercial API sources used for HPLC-MS system were proven to be applicable to the SFC-MS system with no modification [11,21,38-41], However, some modification in the SFC-MS interface may be desired for SFC to achieve stable operation and enhanced ionization [22], The ideal interfaces for SFC-MS would provide uniform pulse free flow, maintain chromatographic integrity, and ionize a wide range of analytes. 

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