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Impact of Operation Conditions on Chromatographic Separation
The operation conditions have a great influence on chromatographic separation. Column length and column inner diameter: Generally, if the length of column is increased, the separation ability can be improved accordingly. Smaller column inner diameter, better separation performance. Larger column innder ...
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Comparison of Chromatographies
Paper chromatography, thin layer chromatography, high performance liquid chromatography and gas chromatography are widely applied chromatographic techniques. They have their own advantages and disadvantages and application scopes. Paper chromatography is the cheapest one of them, however, its time of ...
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Chromatography categorized by stationary phase shape
1. Column chromatographyIf stationary phase is installed in the chromatographic column, it is called column chromatography.Column chromatography can be categorized again by its size, structure and making method. Therefore, there are packed column chromatography, capillary column chromatography or open ...
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Introduction to chromatography
Chromatography is a high-performance physical separation technique, which is used in analytical chemistry with suitable measurement approach. The first application of chromatography is used to separate plant pigments. The method is: put calcium carbonate in a glass tube, and put petroleum ether containing ...
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Precautions for use of gas generators
(1) Hydrogen generator Check desiccant of generaotr. Replace it in time. If desiccant is broken, its alkali solution will damage the generator. (2) Air generator Replace molecular sieve and desiccant regularly. (3) Nitrogen generator If the purity of gas source is not high, try not to use ECD.
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Precautions for use of high pressure gas cylinder
(1) Gas cylinder should be placed in a well ventilated place, away from sunlight, comply with precautions of use of liquefied gas. (2) Environment temperature is below 40℃. (3) Fire is forbidden within 2m from gas cylinder, at the time, fire fighting equipment should be provided. (4) Check leakage ...
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General principle of carrier gas selection
• Inert gas (No chemical reaction with sample or stationary phase during analysis)• Non-corrosive• Do not decompose in temperature range of 200℃ to 400℃• Small gas diffusion coefficient to improve column efficiency• Reasonable price• Do meet the requirements of detectors
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Selection of carrier gas of gas chromatographic system
Gas source is the place where the carrier gas and auxiliary gas comes from. Generally the carrier gases are hydrogen, nitrogen, helium, argon and air etc. The selction of carrier gas is based on requirements of detector, and also the effect of analytic method to analytic period, column efficiency and ...
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How to replace voltage-boosting transformer of MG-II dielectric strength test se
1. Remove two white color high voltage columns in high voltage chamber. 2. Remove four screws at four-corner of the panel, then, slightly lift up the panel. 3. You will see there are four screws at four-corner of the baseplate, remove these four screws, replace the transformer. 4. Re-install the test ...
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Quality Index System of Oil
Good oil has a fixed quality index system (QQIN). It is measured by the ratiio of interfacial tension (IFT) to neutralization number (NN). Generally, for a good oil, QQIN is 1500. QQIN = IFT/NN
