Catecholamines electrochemical properties

Iodide in urine [39] and catecholamines [40,41] are example of analytes recently detected electrochemically and studied under IPC conditions. Pulsed amperometric detection on a gold electrode was used to detect etimicin [42] and gentamicin [43] in commercial samples, thus avoiding tedious pre-column derivatization. Heterocyclic aromatic amines in soup cubes [44] were determined by a coulometric electrode array detector, and the coulometric detection of a quinone-bearing drug candidate [45] allowed the study of electrochemical properties. 

The formation and characterization of ultrathin film formed by poly(3-amino-benzoic acid) (PABA) was carried out by Sriwichai et al. [55] using ESPR for the development of immunosensor to detect human immunoglobulin G. With the aid of simultaneous measurements of SPR and CV it has been become possible to calculate the thickness and dielectric properties of a polymeric film, allowing that immunosensor responses can be related to its surface morphology. Another ESPR biosensor also based on PABA was developed by Baba et al. [56] to detect adrenaline. The polymer acts as a specific reaction site for adrenaline, presenting different electrochemical and SPR responses to those for uric and ascorbic acids, which are major interferences of the catecholamine studied. The two techniques were used to evaluate the electrodeposition of PABA and to obtain the calibration curves and the detection limit was set to 100 pmol... 

Electrochemical detection in HPLC has become established for some, more specialized, applications such as catecholamine analysis though it can be exploited for a far wider range of compounds. The work in this paper has attempted to investigate some of the basic properties of an electrochemical detection system and some more difficult applications. The detector has a linear dynamic range and precision that are comparable with those of other detectors for HPLC. It is, however, more dependent on temperature than, for example, the UV absorption detector and must be operated in a temperature controlled environment to obtain the lowest detection limits. For many electroactive compounds with moderate oxidation potentials, the electrochemical detector can yield sub-nanogram detection limits. 

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