Field-amplified sample stacking

Matson, M. T., Ramstad, T., and Dunn, M. J. (2005). Purity determination of alprostadil by micellar electrokinetic chromatography with signal enhancement involving field-amplified sample stacking and extended path length detection. /. Liq. Chromatogr. Relat. Technol. 28, 3181—3203. 

H.H. Yeh, Y.H. Yang, J.Y. Ko, S.H. Chen, Sensitive analysis of donepezil in plasma by capillary electrophoresis combining on-column field-amplified sample stacking and its application in Alzheimer s disease, Electrophoresis 29 (2008) 3649-3657. 

Abbreviations FASS, field-amplified sample stacking LOD, limit of detection LVSS, large-volume sample stacking MEKC, micellar electrokinetic chromatography. 

Another example of field-amplified sample stacking, which occurs during pinched injection, has been described in Chapter 4, section 4.1.1. 

FIGURE 5.3 Electropherograms of fluorescein and BODIPY separations (a) without and (b) with field-amplified sample stacking. Fluorescence signal is normalized with exposure time in both plots. The position of the detector is 10 mm from the downstream channel intersection of the chip. The signal increase is 1100-fold for the stacked case, and resolution increases from 3 to 120 [584]. Reprinted with permission from Wiley-VCH Verlag. 

Bharadwaj, R., Santiago, J.G., Optimization of field amplified sample stacking on a microchip. Micro Total Analysis Systems, Proceedings 5th pZAS Symposium, Monterey, CA, Oct. 21-25, 2001, 613-614. 

Wey AB, Zhang C-X, Thormann W. Head-column field-amplified sample stacking in binary system capillary electrophoresis. Preparation of extract for determination of opioids in microliter amounts of body fluids. J Chromatogr A 1999 853 95. 

Fig. 1 Capillary electrophoretic separation of opiates. Running conditions 100 mM phosphate buffer pH 6.0. Electrokinetic injection with field-amplified sample stacking after solid-phase extraction of spiked urine using double mechanism cartridges. Precision of migration times 1.2% R.S.D. (relative standard deviation), resolution >2 with all peaks shown. Within the day and day-to-day repeatability 1-4% R.S.D., respectively detection by UV at 200 nm. Peak identification pholcodine (P), MAM (6-M), heroin (H), codeine (C), morphine (M), dihydrocodeine (D), and levallorphan (I.S.) E represents an unidentified endogenous compound present in urine (see inset). (From Ref. 9 with permission.)...

Leung, S. A. and de Mello, A. J., Electrophoretic analysis of amines using reversed-phase, reversed-polarity, head-colunm field-amplified sample stacking and laser-induced fluorescence detection, J. Chromatogr., 979, 171-178, 2002. 

Liu, Z., Sam, R, Sirimanne, S.R., McClure, P.C., Grainger, J., and Patterson, D.G, Field-amplified sample stacking in micellar electrokinetic chromatography for on-column sample concentration of neutral molecules, J. Chromatogr. A, 673, 125, 1994. 

Weng, Q., Xu, G, Yuan, K., and Tang, P. Determination of monoamines in urine by capillary electrophoresis with field-amplified sample stacking and amperometric detection. J. Chwmatogr. B, 835, 55, 2006. 

Garcia-Villar, N., Saurina, J., and Hernandez-Cassou, S., Capillary electrophoresis determination of biogenic amines by field-amplified sample stacking and in-capillary derivatization. Electrophoresis, 27, 474, 2006. 

Field-amplified sample stacking is a fairly widely applicable method of achieving increased sensitivity for capillary and on-chip assays in a scheme that is easily integrated with electrophoretic separation techniques [4,34-43]. FASS is typically used as a preconcentration step that occurs before the electrophoretic separation of analyte ions. 

Jung, B., Bharadwaj, R., and Santiago, J.G, Thousand-fold signal increase using field amplified sample stacking for on-chip electrophoresis. Electrophoresis, 2003, 24 3476-3483. 

Field-amplified sample stacking (FASS) is a preconcentration technique which is commonly used in CE. The technique was first mentioned by Mikkers et al. in 1979 and has been intensively studied by Burgi and Chien et al." In 1995, Jacobson and Ramsey reported the first FASS experiment on a microchip. 

Zhang, L. and Yin, X. F., Field amplified sample stacking coupled with chip-based capillary electrophoresis using negative pressure sample injection technique. Journal of Chromatography A, 1137, 243-248, 2006. 

Beard, N. R, Zhang, C.-X., and dcMello, A. J., In-column field-amplified sample stacking of biogenic amines on microfabricated electrophoresis devices. Electrophoresis, 24, 732-739, 2003. 

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