Electrophoretic instruments detector systems

General. Commercially available polyimides were used (see Table I). Solvents were reagent grade or better and were used as received. 1-Methylpiperazine (Aldrich Chemical Co.) was > 99.9% pure. Lactic acid (Aldrich) was reduced to 50% by weight in water and refluxed for an hour to hydrolyze esters. IR spectra were recorded on a Perkin-Elmer Model 1430 spectrometer. Thermogravimetric analysis was done on a P-E System 4/TGS-2 instrument. Size exclusion chromatography was done on a Perkin-Elmer Series 3B equipped with the LC-75 spectrophotometric detector. The column set used consisted of P-E 0258-2134, 2133, and 2131 columns (pore sizes 103, 104, and 106 A, respectively). For electrophoretic deposition experiments, a TCR Power Supply (Electronic Measurement Systems Inc.) was used. Temperatures are reported in °C throughout. 

Capillary zone electrophoresis (CZE) is a powerful technique, magnetic in its analytical personality as a result of the simple way diverse analytes can be resolved rapidly and with high efficiency. The attraction is easy to understand—an electrophoretic technique with as much bandwidth as (and complementary to) HPLC and multiple modes of separation available by simply changing the buffer system. Yet within the simple instrumental framework that is, at its root, a power supply, a capillary and a detector, lies the capability to analyze drugs, peptides, carbohydrates, and proteins in sample matrices as simple as buffer or as complex as semm. That power is the magnet that draws people in. 

We will see the instrumentation of capillary electrophoresis system shortly. Till that, it will suffice to bear in mind that the basic arrangement of the system is just like what you have studied for other electrophoretic techniques in this book. Typically, a capilleuy connects two buffer reservoirs. The buffer reservoirs have electrodes dipped into them. The capillary passes through a detector. When sample is loaded onto this capillary and voltage applied across electrodes, electrophoretic separation takes place. 

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