Difference between revisions of "Determination of Total Cl in Organic Liquids"
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(Created page with "<br> Natural Cl has the two stable isotopes <sup>35</sup>Cl(35%) and <sup>37</sup>Cl(65%). Thermal neutrons induce the two reactions <sup>35</sup>Cl(n,<math>\gamma</math>)36Cl (...") |
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− | + | ====== Written and developed by [http://www.mn.uio.no/kjemi/personer/vit/torbjor/index.html Prof. Tor Bjørnstad] (IFE/UiO) ====== | |
− | + | Return to [[Neutron Activation Analysis|Main]] | |
+ | <br> Natural Cl has the two stable isotopes <sup>35</sup>Cl(35%) and <sup>37</sup>Cl(65%). Thermal neutrons induce the two reactions <sup>35</sup>Cl(n,<span class="texhtml">γ</span>)36Cl (T<sub>1/</sub><sub>2</sub> = ) and <sup>37</sup>Cl(n,<span class="texhtml">γ</span>)<sup>38</sup>Cl (T<sub>1/2</sub> = 37.3 min). Only the second reaction is useful here. The actual gamma energies for <sup>38</sup>Cl are 1642.7 keV and 2167.6 keV. | ||
+ | <br> | ||
− | The detailed procedure is:<br> | + | The detailed procedure is:<br> |
− | #Team 1 and Team 2 go to the detector room where a teacher will demonstrate the counting equipment. These teams will then be well prepared for the counting procedure after the following practical procedure. | + | #Team 1 and Team 2 go to the detector room where a teacher will demonstrate the counting equipment. These teams will then be well prepared for the counting procedure after the following practical procedure. |
− | #Team 3 and Team 4 go to the preparation laboratory and carry out the following procedure: | + | #Team 3 and Team 4 go to the preparation laboratory and carry out the following procedure: |
− | #Prepare a Cl-standard: Dry KCl in a heating cabinet at 110 | + | #Prepare a Cl-standard: Dry KCl in a heating cabinet at 110 <sup>o</sup>C for 24 h. Cool in a deccicator. Weigh exactly in ca. 0.21 g KCl and dissolve to 100.00 ml in a measuring flask with distilled water. This standard is approximately 1000 ppm. |
− | #For the present analysis we will operate with a working standard of about 100 ppm. Take an aliquote of 10 ml from the standard and dilute to 100 ml with distilled water. | + | #For the present analysis we will operate with a working standard of about 100 ppm. Take an aliquote of 10 ml from the standard and dilute to 100 ml with distilled water. |
#Prepare 4 plastic irradiation ampoules by heat-sealing adequate lengths of a plastic (polyethylene) tubing in one end. | #Prepare 4 plastic irradiation ampoules by heat-sealing adequate lengths of a plastic (polyethylene) tubing in one end. | ||
− | #To one ampoule transfer a fraction of 1.00 mL from the working standard. Heat-seal and label. | + | #To one ampoule transfer a fraction of 1.00 mL from the working standard. Heat-seal and label. |
− | #To the three others transfer 3 parallels of 1.00 mL of the organic unknown sample. Heat-seal and label. | + | #To the three others transfer 3 parallels of 1.00 mL of the organic unknown sample. Heat-seal and label. |
− | #Pack the ampoules into a rabbit container. | + | #Pack the ampoules into a rabbit container. |
− | #Arrange irradiation with the reactor control room. | + | #Arrange irradiation with the reactor control room. |
− | # Irradiate the sample 5 min and transfer back to the lab. | + | # Irradiate the sample 5 min and transfer back to the lab. |
− | # After irradiation wash the ampoules on the outside with the washing solution sequence acetone-water-acid mixture-water-acetone. Every ampoule is washed for 5-10 s in each solution. | + | # After irradiation wash the ampoules on the outside with the washing solution sequence acetone-water-acid mixture-water-acetone. Every ampoule is washed for 5-10 s in each solution. |
− | # Samples are transferred to the counting laboratory and a demonstration is given of the counting equipment for teams 3 and 4. | + | # Samples are transferred to the counting laboratory and a demonstration is given of the counting equipment for teams 3 and 4. |
− | #Position the first sample in front of the detector inside the lead shield and start counting. Start the stop-clock. Counting time 5-10 min. | + | #Position the first sample in front of the detector inside the lead shield and start counting. Start the stop-clock. Counting time 5-10 min. |
− | #Count the two other samples and the standard in the end. | + | #Count the two other samples and the standard in the end. |
#Integrate the appropriate peaks and note the results.<br><br> | #Integrate the appropriate peaks and note the results.<br><br> | ||
+ | |||
+ | [[Category:Laboratory_exercise]] [[Category:Master]] |
Latest revision as of 10:51, 9 July 2012
Written and developed by Prof. Tor Bjørnstad (IFE/UiO)
Return to Main
Natural Cl has the two stable isotopes 35Cl(35%) and 37Cl(65%). Thermal neutrons induce the two reactions 35Cl(n,γ)36Cl (T1/2 = ) and 37Cl(n,γ)38Cl (T1/2 = 37.3 min). Only the second reaction is useful here. The actual gamma energies for 38Cl are 1642.7 keV and 2167.6 keV.
The detailed procedure is:
- Team 1 and Team 2 go to the detector room where a teacher will demonstrate the counting equipment. These teams will then be well prepared for the counting procedure after the following practical procedure.
- Team 3 and Team 4 go to the preparation laboratory and carry out the following procedure:
- Prepare a Cl-standard: Dry KCl in a heating cabinet at 110 oC for 24 h. Cool in a deccicator. Weigh exactly in ca. 0.21 g KCl and dissolve to 100.00 ml in a measuring flask with distilled water. This standard is approximately 1000 ppm.
- For the present analysis we will operate with a working standard of about 100 ppm. Take an aliquote of 10 ml from the standard and dilute to 100 ml with distilled water.
- Prepare 4 plastic irradiation ampoules by heat-sealing adequate lengths of a plastic (polyethylene) tubing in one end.
- To one ampoule transfer a fraction of 1.00 mL from the working standard. Heat-seal and label.
- To the three others transfer 3 parallels of 1.00 mL of the organic unknown sample. Heat-seal and label.
- Pack the ampoules into a rabbit container.
- Arrange irradiation with the reactor control room.
- Irradiate the sample 5 min and transfer back to the lab.
- After irradiation wash the ampoules on the outside with the washing solution sequence acetone-water-acid mixture-water-acetone. Every ampoule is washed for 5-10 s in each solution.
- Samples are transferred to the counting laboratory and a demonstration is given of the counting equipment for teams 3 and 4.
- Position the first sample in front of the detector inside the lead shield and start counting. Start the stop-clock. Counting time 5-10 min.
- Count the two other samples and the standard in the end.
- Integrate the appropriate peaks and note the results.