Temperature‐programmed microcolumn liquid chromatography/mass spectrometry

Abstract

Abstract. A temperature-programmed microcolumn liquid chromatography/mass spectrometry (LC/MS) system has been developed as a practical alternative to conventional solvent-programmed LC/MS. Good reproducibility of solute retention was achieved in a specially modified oven that permitted linear temperature programming between 40 and 100°C at rates of 0.1 to 0.5"C min-'. Through theoretical modelling studies performed under isocratic and isothermal conditions, the optimum separation under temperature-programmed conditions was rapidly and accurately predicted. This method enabled the complete resolution of saturated and unsaturated fatty acids in a fish oil dietary supplement with identification from their characteristic fragmentation patterns under electron-impact MS conditions. The mass spectra from the LC/MS system correlated very well with those from a standard reference library to facilitate spectral searching methods.

Elevated temperature liquid chromatography using reversed-phase packed capillary columns

“…w x Greibrokk and co-workers 23 concluded that the benefits of using elevated temperatures in LC with packed capillaries are represented more by improved peak shapes and shorter analysis times than by plate numbers. On the other hand, Sandra w x et al 24 found a slight increase in selectivity at w x high temperatures. McGuffin and co-workers 25 reported the advantages of temperature-programmed microcolumn LCrmass spectrometry Ž .…”

Controlling the retention in capillary LC with solvents, temperature, and electric fields

“…The drift could be corrected mathematically [104]. The compatibility between temperature programming in LC and MS was shown a decade ago [134], and recently also with electrospray ionization [107,117]. Since temperature programming can be expected to affect the ionization process in electrospray ionization less than solvent gradients, tem-perature programmed LC-MS may in many cases be a better choice than using solvent gradient LC-MS, where addition of sheath liquids may be necessary to maintain the sensitivity throughout the gradient.…”

Some advantages of high temperature for the separation of pharmaceutical compounds with mass spectrometry detection

“…Most likely, all these effects contribute to the peak shape improvement. Furthermore, the compatibility between HTLC and MS was shown more than a decade ago [14][15][16][17].…”