Simple, ionic, liquid chromatography separation

Liquid chromatography can be operated under mild conditions in terms of pH, ionic strength, polarity of liquid, and temperature. The apparatus used is simple in construction and easily scaled up. Moreover, many types of interaction between the adsorbent (the stationary phase) and solutes to be separated can be utilized, as shown in Table 11.1. Liquid chromatography can be operated isocratically, stepwise, and with gradient changes in the mobile phase composition. Since the performance of chromatography columns was discussed, with use of several models and on the basis of retention time and the width of elution curves, in Chapter 11, we will at this point discuss some of the factors that affect the performance of chromatography columns. 

A simple and sensitive liquid chromatographic method coupled with ECL was developed for the separation and quantification of naproxen (a nonsteroidal antiinflammatory drug) in human urine. The method was based on the ECL of naproxen in basic NaN03 solution with a dual-electrode system. The detection limit was 1.6 x 10 g mL (S/N = 3) [58]. Furthermore, MEKC chromatography was used with ECL of Ru(bpy)3 as a fast and sensitive approach to detect an antipsychotic and antihypertensive drug, i.e., reserpine in urine. Field-amplified injection was used to minimize the effect of ionic strength in the sample and to achieve high sensitivity. In this way, the sample was analyzed directly without any pre-treatment with LOD (S/N = 3) to be 7.0 x 10 mol L [59]. 

---