Among all chromatographic techniques, liquid chromatography (LC) was first invented (1903), but its initial development was relatively slow. Before the popularization of liquid chromatography, paper chromatography, gas chromatography and thin layer chromatography Method is the mainstream of chromatographic analysis. In the late 1960s, the theory and technology of gas chromatography, which had been developed relatively maturely, were applied to liquid chromatography, which led to the rapid development of liquid chromatography. In particular, the continuous improvement of packing preparation technology, detection technology and high-pressure infusion pump performance has enabled liquid chromatography analysis to achieve high efficiency and high speed. Liquid chromatographs with these excellent properties were commercialized in 1969. From then on, this kind of liquid chromatography with high separation efficiency and fast analysis speed is called high performance liquid chromatography (HPLC), also known as high pressure liquid chromatography or high speed liquid chromatography. Types of HPLC According to the separation mechanism, liquid chromatography is generally divided into four categories: adsorption chromatography, partition chromatography, ion chromatography and gel chromatography. In fact, some liquid chromatography methods cannot simply fall into these four categories. According to the separation mechanism, some of them are the same or partially overlap. However, these methods are either unique in the application object or different in the separation process, and are usually given a relatively fixed name. Type Main separation mechanism Main analysis object or application area Adsorption chromatography Adsorption energy, hydrogen bond isomer separation, family separation, preparation partition chromatography Hydrophobic partition function Separation, analysis and preparation of various organic compounds Gel chromatography solute molecular size polymer separation , Determination of molecular weight and its distribution Ion exchange chromatography Coulomb force inorganic ions, organic ions analysis Ion exclusion chromatography Donnan membrane balance organic acids, amino acids, alcohols, aldehydes Analysis ions on chromatographic hydrophobic partitioning ionic substances analysis hydrophobic interaction chromatography hydrophobic partitioning proteins Separation and purification Chiral chromatographic stereo effect separation of chiral isomers, drug purification affinity chromatography biochemical specific affinity protein, enzyme, antibody separation, biological and pharmaceutical analysis Wpc Decking,Wpc Outdoor Flooring,Wood Composite Decking,Wpc Cladding And Decking ZHEJIANG DEQING GONAT FENCE CO.,LTD , https://www.gonatfence.com
Gas chromatography is only suitable for analyzing organic compounds that are more volatile and chemically stable, while HPLC is suitable for analyzing substances that are difficult to analyze by gas chromatography, such as poor volatility, strong polarity, biological activity, and poor thermal stability. Now, the application range of HPLC has far exceeded gas chromatography, ranking first in chromatography.
Broadly speaking, the paper chromatography and thin layer chromatography with a stationary phase as a plane also use liquid as the mobile phase and should also be attributed to liquid chromatography. However, the general term liquid chromatography refers only to column liquid chromatography with a stationary phase as the column type.
Table 8-1 HPLC classification according to separation mechanism
Liquid chromatography flow chart