The Chromatography Forum

of Delaware Valley

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Abstract:
Many compounds (e.g., amino acids, carbohydrates, and ions) lack a native chromophore or fluorophore, thereby necessitating derivatization for their detection by optical spectroscopy. Electrochemical approaches are often able to detect these compounds with the advantage of not requiring chemical modification prior to detection. While conductivity is the preferred means of detection for most common ions, other electrochemical approaches have played a critical role as detectors following ion chromatographic separations. For instance, the detection of carbohydrates by Pulsed Electrochemical Detection (PED) is sensitive, reproducible, and direct. PED offers only a limited degree of voltammetric selectivity, and, as such, its true benefit is only realized following a chromatographic separation. The highly alkaline mobile phases required for maximum sensitivity of PED at gold electrodes is ideally suited to the use of polymeric ion-exchange phases (e.g., high performance anion exchange chromatography (HPAEC) for carbohydrates) because of their stability at pH extremes. Similarly, metal ions separated under low pH conditions can be sensitively detected using a modified version of PED, and ions with no inherent electroactivity have been determined using Indirect-PED (InPED). InPED following anion-exchange chromatography has been used to detect biotin, amino acids, and other pharmaceuticals of interest.

In this presentation, an historical overview of PED from its inception (a serendipitous coupling of academia and industry) through waveform development (a coupling of theory and analytical utility) to a plethora of applications (a coupling of scientific needs and solutions) will be presented. The quantitative and qualitative aspects of HPAEC-PED will be highlighted with a review of “real-world” applications involving pharmaceutical, forensics, and biological samples.

Late reservations (after 4 PM on December 6): We still want you to attend, so please call or email Ms. Sheree Gold at 610-742-4981 or sheree@cfdv.org. However, we cannot guarantee your entrée selection for dinner.

Non-weather-related cancellations: The deadline for ‘good weather’ cancellations is 36 hours prior to the meeting, i.e., noon on December 8th for the meeting on Tuesday, December 10. Cancellations after the deadline cannot be accepted and ‘no shows’ will be billed for dinner if it was not already paid in advance.