Operation of the liquid chromatography-electrochemical system

As mentioned above, flow in an electrochemical cell is no problem if it is constant, which certainly will be the case with an HPLC effluent. Flow can even be useful, as it promotes the occurrence of stationary diffusion, even at plane electrode surfaces. For this reason, electrochemists have even been working with flowing solutions, without thinking about LC coupling, 

With these electrodes detection limits of about 10 mole/1 (column outlet) could be obtained. Taking into account a molecular weight of 100 and the usual dilution within the column (factor 3-10), concentrations in samples of 10 ppm can be analysed selectively with 1.0% precision. It is noteworthy that the detection limits are lower than those obtained in batch measurement in normal d.c. polaro-graphy. The same phenomenon, better detection limits in flow systems, is observed with UV absorption measurement absorbance values more precise than 0.001 a.u. can hardly be obtained in batch measurements, but in the combination with LC, it is coimion to work at 0.01 a.u. full scale with one Scale division noise. The current yield of this DME device is approximately 1%, corresponding to a diffusion-layer thickness of about 10 pm. Recent work with the DME was described by 24 

Wasa and Musha, who used a horizontal capillary. The contribution to peak 

Fleet also described a design for the use of the DME in HPLC detection , and used it with a pulse method. A recent paper described the use of tensamnetry for 

DDT isomers, amino acids , alkaloids , aldehydes and ketones, inorganic 

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