ECD 电子捕获检测器

ECD is a radioactive ionization detector, which is the use of radioisotopes, in the decay process of radiation with a certain energy of β-particles as the source of ionization, when only the pure carrier of its molecules through the ion source, the β-particle Ionization and ionization into positive ions and free electrons in the role of the applied electric field will do the ion and electrons move, because the electrons move much faster than the positive ions, so the probability of positive ions and electronic recombination is very small, as long as When the carrier gas with a small amount of electronegative components into the ion chamber, the electrophilic components, a large number of electrons to form negative ions or negative charged molecules. (2) the formation of a certain ion current (base flow). Because the negative ions (molecules) and the positive ion is almost the same rate of positive ions and negative ions than the positive ions and electron compound probability of 105 to 108 times higher, and thus the base flow decreased significantly, so the instrument output a negative polarity of the electrical signal, Therefore, in contrast to FID, the output of the measured component by ECD gives a negative peak in data processing.

1. ECD came out in 1961, it and FID, chromatographic temperature analysis called chromatographic development in the three major breakthroughs;

2. It is a high sensitivity, high selectivity detector, sensitive to electronegative substances;

3. The minimum detection amount of up to 10-13 grams (γ -666), the sensitivity of carbon tetrachloride and n-hexane ratio of 4 × 108 times;

4. It is mainly used for the analysis and determination of halides, phosphorus (sulfur) compounds and peroxides, nitro compounds, metal organic compounds, metal chelates, steroids, polycyclic aromatic hydrocarbons and conjugated hydroxy compounds such as electronegative substances. In addition can also analyze 1PPM oxygen;

5. The use of chemical conversion method, it has a strong electronegativity of the derivative and expand the use of electron capture detector range;

6. ECD has become one of the most widely used detectors in the fields of food inspection, pesticide residues in animal (plant) and environment (water, soil, air pollution, etc.).

电子捕获检测器

电子捕获检测器 详细信息：