This experiment is from the official website of College of Chemistry, Qingdao University of Science and Technology.
Operation method
Determination of O in samples by elemental analysis
Principle
The O-mode working principle of the Elemental Analyzer is as follows: Inject helium into the high temperature cracking column equipped with graphite, so that the sample is cracked at high temperature under the environment of inert gas, and the oxygen contained in the sample is completely converted to CO, and other products generated by cracking are absorbed in the helium carrier gas, such as acidic gases H2S, HCN, HCl, etc. flowing through the drying tube equipped with a NaOH filler layer, and neutral cracking gases such as N2 and CH4 gases flowing through the CO adsorption column are separated out, and then a thermal conductivity detector (TCD) is used to measure the CO gas content. N2 and CH4 gases are separated by the CO adsorption column, and then the CO gas content is measured by thermal conductivity detector (TCD), and then calculated by the data processor, the weight percentage of oxygen can be listed automatically. The sample analysis flow chart is shown below: Move boot-up procedure Caveat Sulfur and alkaline samples require 1׃1 of tetrazolium hexahydroxide and ammonia chloride for accurate testing. For more product details, please visit Aladdin Scientific website.
Turn on the computer, enter the WINDOWS state, pull out the two plugs of the host exhaust will be the host of the sample tray to one side to open the host power, to be the base of the sample tray self-test is completed that is, rotate one week, the sample back to the original place.
Turn on the helium gas and adjust the pressure reducing valve to: He: 0.5 MPa.
Start the WINVAR software.
Operation program
Selecting the label STANDARD
Enter the dialog window of the standard, input the name of the standard.
Benzoic Acid, can be abbreviated as Benz Enter the theoretical value of CHNS% and select FACTOR SAMPLE for correction factor calculation.
Select CALIBRATION SAMPLE for calibration curve calculation.
General Analysis
Instrument warming A
Enter the OPTIONS function, enter the PARAMETERS function.
Enter operating temperature: Furnace 1: 1150 °C
Instrument temperature rise B (helium-saving method)
Enter SLEEP/ WAK UP function
Activate the ACTIV REDUCE GASFLOW function.
Enter 10 in the ACTIVE REDUCE GAS FLOW field.
To activate the SLEEP NOW function
After the temperature has risen to the specified temperature, enter the SLEEP/ WAK UP function again to activate the WAKE UP function, or activate the AUTO function directly.
Input of sample weight and name
Enter the EDIT editing function and then the INPUT function.
Enter the name of the sample in the NAME field and the weight of the sample in the WEIGHT field.
Suggested sample measurement sequence (CHNS mode)
1 blank
3 RUN-INs (non-weighed samples, approx. 2-3 mg)
3 Benz (benzoic acid weighing, ~2-3 mg range)
20 samples (weighed according to the nature of the sample)
2 Benz (benzoic acid, weighed, approx. 2-3 mg range)
20 samples (weighed according to the nature of the sample)
2 Benz (benzoic acid, weighed, approx. 2-3 mg range)
20 samples (weighed according to the nature of the sample)
Calibration of specimens
Check if the data of the 3 samples are parallel, if they are parallel, enter the MATH function and activate the FACTOR function. If the data of one of the 3 samples are not parallel, enter the EDIT function, then enter INPUT and activate the TAGGED function on the two samples.
If one of the three samples is not parallel, enter EDIT, then INPUT, and activate TAGGED on both samples, then enter MATH, then enter FACTOR SETUP, activate COMPUT FACTORS FROMTAGGED STANDARDS (with #), and then activate the FACTOR function in the MATH function, and then activate the FACTOR function in the MATH function, and then activate the FACTOR function in the MATH function, and then activate the FACTOR function in the MATH function.
If you analyze the sample for the second time, and if the data of the three samples are parallel, the FACTOR SETUP function is resumed, i.e., the FACTOR SETUP function is activated in this function.
COMPUTE FACTOES SEQUENTIALL
Analytical cycle start
Entering the SLEEP/ WAK UP function and activating the ACTIVE SLEEP TEMPREATURES function activates OK, which automatically puts the sample to sleep after the analysis is completed.
Activate AUTO to analyze the sample.
Shutdown program
After the analysis, the mainframe automatically enters the sleep state, until the temperature is reduced to below 750 ℃ to exit the WINVAR operating software (system-offline-exit), shut down the computer to shut down the mainframe, open the mainframe combustion unit door to dissipate the residual heat.
Turn off the helium gas and block the two outlets of the mainframe exhaust gas.