The Conductivity Detector Has High Sensitivity
Conductivity detector (ELCD) is an electrochemical detector with high selectivity and high sensitivity for halogen, sulfur and nitrogen compounds. It is the measured component into a heteroatom hydride or oxide, Conductivity Detector in the deionized solvent ionization, according to changes in solvent conductivity to detect the original component content. In recent years the conductivity cell volume has been greatly reduced, can be connected with the capillary column. It has been widely used as an element selective detector in the fields of environmental protection, Conductivity Detector medicine and health and biomedicine.
The conductivity detector is based on the conductivity of the ionic compound solution, and its conductivity is related to the nature and concentration of the ions.
First, the conductivity detector structure:
Conductivity detector by the conductivity cell, electronic circuits, Conductivity Detector transform sensitivity devices and digital display devices, etc., the conductive cell is the core part.
The basic structure of the conductivity cell is to place two electrodes in the column effluent, and then through the electronic circuit to measure the conductivity of the solution, Conductivity Detector the detection volume can reach a slight increase or even upgrade.
Second, the conductivity detector works:
When a voltage is applied to the two electrodes of the conductivity cell, the anions in the solution move toward the anode and the cations move toward the cathode. The number of ions in the electrolyte solution and the rate of movement of the ions determine the resistance of the solution. Conductivity Detector The rate of movement of the ions depends on the charge and size of the ions, the type of the medium, the solution temperature and the ion concentration. The applied voltage may be a DC voltage, or it may be a sine wave or a square wave voltage. When the applied voltage is determined, the current value in the circuit can be measured, that is, Conductivity Detector the conductance value can be measured.
Third, the conductivity detector features:
1, high sensitivity, low detection limit is generally nanke class, Conductivity Detector sometimes up to the pico level.
2, selectivity is good, can determine a large number of non-electroactive substances in the trace trace of the electroactive material.
3, wide linear range.
4, simple structure, easy to operate automatically
Fourth, the conductivity detector Application:
The most used in the ion chromatograph.