Introduction

1. discussion poster Jetse Reijenga Setup for Correlation Vacancy Electrophoresis in trace analysis, process monitoring, finger printing, trend analysis Some design parameters All vessels have vacuum/pressure for rinsing. Negative HV (because of EOF) is on detection side, to enable easier isolation of sample vessels (required). Separate design for time-shifted sampling. Some operating parameters Integration time, duty cycle, minimum and maximum sampling length of PRBS in COR mode (depends on sample load) Classic mode of operation Rinse BGE from C to D, then sample from A to B Electrophorize from C to D, classis pherogram Trace analysis mode (COR) Rinse BGE from C to D, then A to B, then sample from A to C Electrophorize from A to D and from B to D programmed by PRBS, then cross-correlate signal with PRBS Quality control or trend anal. (VAC) Rinse reference or current sample from C to D Rinse sample or time-shifted sample from A to B Electrophorize from C to D, givers differential pherogram Trace Quality control (COR+VAC) Rinse reference sample C to D, then A to B Rinse sample A to C Analyse A to D and B to D programmed by PRBS, then cross correlate signal with PRBS Trace trend analysis (COR+VAC) Rinse reference sample C to D, then A to B Rinse time-shifted sample A to C Analyse A to D and B to D programmed by PRBS Cross-correlate signal with PRBS Bottle necks Some of the potential bottle necks of the proposed schemes: On the long run, despite measures taken, EOF drift may occur. On a shorter term, EOF shift will lead to peak broadening, in the long run, to peak shifting; For operation in VAC mode, ghost-peaking [5] may occur; Voltage switching leads to spikes in detector signal. Introduction The aim is to provide a design for modular setup, integrating Correlation Electrophoresis and Vacancy (a.k.a. Differential) Electrophoresis. A block diagram and construction guidelines are given and discussed and the working procedures for different modes of operation are outlined. Targeted fields of application are trace analysis, finger printing, process monitoring and trend analysis. Correlation Electrophoresis Correlation- or mulitplex-, or multiple injection chromatography was introduced for GC and LC by Smit et al [1]. Kuldvee et al also applied the principle to Electrophoresis [2]. Sample (single injection in A) and BGE are injected alternately during the whole detection period, using a file of Pseudo Randomized Binary Sequence (PRBS, [3]) (B). The resulting detection signal (not shown) is then cross-correlated with that same file (B), to obtain a signal with improved S/N ratio (C). A B C Vacancy (differential) Electrophoresis Vacancy (or differential) Electrophoresis was developed by Mikkers [4]. BGE is injected in a separation chamber filled with sample. A negative electropherogram of the sample composition is obtained. Alternatively, a differential electropherogram C of 2 sample solutions S1 and S2 can be obtained. S1 S2 S1 in S2 Building blocks A CE separation chip is to be used, which has 3 entrance (A, B and C) and 1 exit (D) connection to perpendicularly mounted channels, and an optical on-chip detector. Conclusion or ??? References 1. H.C. Smit, Chromatographia 3 (1970) 515 2. R. Kuldvee et al, J. High Resol. Chromatogr. 21(1998) 169 3. M. Kaljurand, E. Küllik, Computerised Multiple Input Chromatography, Ellis Horwood Ltd., Chichester (1989) 4. F.E.P. Mikkers, Anal. Chem. 69 (1997) 333 5. J.L. Beckers, P. Bocek, Electrophoresis 20 (1999) 519 ISSS-2005