Flow Injection Tutorial

A combination of CE with FI was proposed independently by Kuban and by Fang. The feasibility of the method was verified by analysis of inorganic ions in water samples (Kuban 1997) and by separation of magnolol and honokiol (Fang 1997). The apparatus combined a traditional FI setup with a CE system, and their inherent incompatibility, due to vastly different system volumes and flow rates, was overcome by an ingenious interface design. Since then Kuban’s group has remained very active in this field, and has been credited for important advances, as summarized in a recent thorough review of FI/SI CE and CE chip combinations. (Chen 2004).

Reasons for enthusiastic and prolific development in this field are several. Automated sample treatment by FI and SI offers well established advantages - reproducible sample metering, automated sample dilution and sample spiking and automated derivatization prior to CE separation. Also, auxiliary functions such as rapid flushing of capillaries when the desired readout has been recorded (not necessarily the entire electro chromatogram), and even capillary reconditioning are readily accomplished. Clearly, automation of these operations addresses some Achilles’ Heels of CE.

The development of microSI-LOV brings further benefits. No longer is there such a vast difference between flow rates of the LOV system and the operational flow of CE.

The next step in this exciting development is the use of flow programming and low flow

rates provided by Miligat pump, to be used for more precise tuning of flow rates and volumes.

Kuban, P., Engstrom, A., Olsson, J. C., Thorsen, G., Tryzell,R., Karlberg, B., Anal. Chim. Acta 1997, 337, 117.

Fang, Z. L., Liu, Z. S., Shen, Q., Anal. Chim. Acta 1997, 346,135.

X. G. Chen, L. Y. Fan and Z. Hu, Electrophoresis, 2004, 25, 3962.

P. Kuban & B. Karlberg, Talanta, 45, 477 (1998).

P.Kuban & B. Karlberg, Anal. Chim. Acta, 404, 19, (2002).

P. Kuban, P. Hauser” Flow Injection Analysis-Capillary Electrophoresis” Ch11 in Advances In Flow Injection Analysis and Related Techniques, S.D. Kolev and I.D. McKelvie Elsevier 2008.