If you are interested, please contact us!
High performance liquid chromatography (HPLC), its basic concept and theoretical basis (such as retention, plate theory, rate theory, capacity factor, resolution, etc.), consistent with gas chromatography, but with differences . High performance liquid chromatography and gas phase
The main differences in chromatography can be attributed to the following:
(1)
Different injection methods: high-performance liquid chromatography requires the sample to be made into a solution, and the gas chromatograph needs to be heated to vaporize or crack.
solution;
(2)
The difference in mobile phase, there is a certain phase between the measured component and the mobile phase, between the mobile phase and the stationary snap autosampler vials phase.
Interaction
(3)
Since the viscosity of the liquid is two orders of magnitude larger than that of the gas, the diffusion coefficient of the measured component in the liquid mobile phase is
The gas mobile phase is about 4 to 5 orders of magnitude smaller;
(4)
Since the chemical composition of the mobile phase can be widely selected and can be configured as a binary or multi-component system, the gradient wash is satisfied.
The need for removal, thus improving the resolution of high performance liquid chromatography (column efficiency);
(5)
High-performance liquid chromatography uses 5~10Lm fine particle stationary phase, so that the permeability of the fluid phase on the column is greatly reduced, the flow resistance is increased, and the mobile phase must be transported by means of a high-pressure pump;
(6)
High performance liquid chromatography is carried out in the liquid phase. For the detection of the tested components, sensitive wet photometric detection is usually used.
, for example, an ultraviolet photometric detector, a refractive index detector, a fluorescence photometric detector, etc.;
(7)
Compared with gas chromatography, high performance liquid chromatography also has high sensitivity, high efficiency and high speed.
Features.
Qualitative and quantitative analysis of high performance liquid chromatography, similar to gas chromatography analysis,
In the qualitative analysis, the retention value is used qualitatively, or combined with other instrumental analysis methods with strong qualitative ability; in the quantitative analysis, the normalized method, the internal standard method or the external standard method for measuring the peak area is used, but the high-performance liquid phase When chromatographic separation of complex component patterns, some components often do not peak, so the normalization method is limited, and the internal standard method is widely used snap autosampler vials.
This is the end of the introduction of What should be paid attention on Gas chromatograph? I hope it can help you.
