In Comprehensive Analytical Chemistry , The equivalence point is the point at which the conductivity undergoes a sudden change. In recent years, conductometry has been used to measure the p K a of lidocaine, 68 though the result obtained was 0. For this reason, on-column detection is rarely used.
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Views Read Edit View history. The general principles of conductivity detection were presented earlier section 5. This was a widely used method up to aboutbefore pH-metric methods cnductometry over. Due to the unique advantages of the electrochemical immunosensors, they have shown great application potential for the convenient protein measurement in the clinical diagnostic field.
The basic design features of these analyzers are identical and are depicted schematically in Fig. In all cases, the high voltage applied to conductometfy separation capillary can lead to serious interference with the electrochemical signal.
The equivalence point is the point at which the conductivity undergoes a sudden change. Another useful method is based on the reaction of metallic thallium with traces of oxygen dissolved in water:.
Good mass transfer took place between the air and the liquid segments in a small channel and water-soluble species were transferred to the liquid phase. In recent years, conductometry has been used to measure the p K a of lidocaine, 87 though the result obtained was 0.
conductometry - an overview | ScienceDirect Topics
Electrochemical immunosensors combine the specific biorecognition of immunoreaction with the convenient electrochemical signal transduction of biosensors for target detections. Given our aim, the approach differs somewhat from that usually taken in electrochemistry.
The data are convincing evidence of the great potential of conductometric biosensors. High concentrations of hydronium or hydroxide ions increase the background conductivity and reduce the detector response to sample ions.
The detection of the current generated by reaction at the surface of usually carbon fiber or copper microelectrodes at a fixed voltage is capable of low detection limits for electroactive compounds using amperometry, Table 8. In recent years, conductometry has been used to measure the p K a of lidocaine, 68 though the result obtained was 0.
connductometry Peck and Benet 88 described a general method for estimating p K a values for monoprotic, diprotic, and amphoteric substances, given a set of solubility and pH measurements. Thallium is inert in water, while thallium hydroxide produced by reaction with traces of oxygen is soluble in water and increases its conductivity.
The determination of hydrogen sulphide is based on the reaction with an aqueous bromine solution: Most of the above reactions are utilized for determinations in automatic analyzers. Peck and Benet 69 described a general method for estimating p K a values for monoprotic, diprotic, and amphoteric substances, given a set of solubility coneuctometry pH measurements.
The short gap between the column outlet and sensing electrode serves to decouple the detector signal from the influence of the separation voltage without inducing significant band broadening.
Dasgupta, in Comprehensive Analytical Chemistry4. Kalcher, "History of Electroanalytical Methods". The strong temperature dependence of the electrical conductivity is a disadvantage and must be eliminated by simultaneous measurement of the conductivity of the pure reagent, and by thermostatting both cells.
Selectivity to NH 3 was achieved by collection of NH 3 in an acidic solution and re-vaporization by basification. Also typical is our choice of model systems, featuring substances that can be dispersed to give a sol or suspension, like silver iodide, oxides and clay minerals, or liquids, to give emulsions.
A possible advantage for samples without a chromophore is that it can be used in very dilute solutions, down to 2. This concentration range must be maintained as the dependence of the conductivity on the dilution is greatest in this region. The application of conductometric measuring method to continuous recording in the course of enzyme processes has been thoroughly examined and analysed.
For integral microbiosensors it is conructometry to perform a differential measurement mode, thus compensating for external effects and considerably increasing measurement accuracy.
After removing the iodine produced in the reaction e.