| 1. (a) | EITHER describe a high performance liquid chromatography (HPLC)
injection system
OR describe a gas chromatographic (GC) injection system |
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| (b) | EITHER explain how an electron-capture detector works
OR explain how a refractive index detector works |
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| (c) | Considering the orientation of the instrument, explain the difference between an absorption experiment and an emission (fluorescence) experiment using UV-visible radiation. | ||||||
| (d) | Samples for infrared spectroscopy are commonly prepared in one of these three forms: (i) nujol mull, (ii) solution, (iii) KBr pressed-pellet. Compare the relative merits of any 2 of these three methods. | ||||||
| (e) | EITHER explain the basis of size exclusion chromatography
OR explain electroosmotic flow |
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| 2. | A phenol has a distribution constant between hexane and water of 6.25. A contaminated water sample (25.0 mL) is 0.0600 M in the phenol. What is the concentration remaining in the water after 5 extractions with hexane if each extraction uses a volume of 5.00 mL? | ||||||
| 3. | An HPLC experiment has the following parameters:
Length 24.7 cm Flow rate 0.313 mL/min VM 1.37 mL VS 0.164 mL
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| 4. | EITHER: Based on the information given in Question 3,
calculate the length of column required to completely resolve the two peaks
PCB-A and PCB-B (i.e., a resolution of 1.5).
OR: KMnO4 has a molar absorptivity (e) of 5.57 x 103 L mol-1 cm-1, and MnO2 is colourless (e = 0) at 525 nm. 0.0600 g of a mixture of MnO2 and KMnO4 are dissolved in 1.00 L of water. The absorbance of this solution at 525 nm is 1.586 (sample cell = 1.00 cm). What is the (mass) percent of KMnO4 in the original mixture? |
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Last updated, February 27, 2003
Page maintained by Craig
MacKinnon