The world leader in serving science Transmission Techniques Liquids

2 Liquid Transmission  Smear  Capillary Film  Sealed Cell  Demountable Cell

3 Smear  Great for viscous liquids, greases, oil, or gels  Support system is window material  Qualitative tool

4 Technique  Place a small amount of sample on a window  Using a second window squeeze out any excess sample and air bubbles by rotating  Sample may be removed or added to adjust for optimal absorbance  Use clean window or open beam for background

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6 Smear Trouble Shooting

7 Quantitative Analysis  Quantitative analysis results are difficult to obtain without large errors  Can not control pathlength  Much better techniques available

8 Capillary Film  Excellent way to run liquid samples  Samples are run neat  Very quick with no sample prep  Preferred for viscous and volatile samples

9 Technique  Put two drops of sample on window  Place second window on top  Squeeze windows together to remove any air bubbles and produce a even thin film

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11 Quantitative Analysis  Quantitative results are hard to reproduce  Pathlength problems  Air bubbles issue  Consistent mass problem

12 Sealed Cell  Precision Pathlength  Precise Quantitative analysis  Reproducible Experiments  Automate Process  Can be difficult to clean

13 Technique  Placing cell on incline use a syringe to inject sample slowly (Bottom up)  Another syringe may be used to create a vacuum on the cell  Plug cell tight with Teflon TM stoppers  Use interference fringes on empty cell to calculate pathlength  Clean with appropriate solvent thoroughly

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16  Automated pumping system alleviates human error and reduces sampling time  Can be integrated with software for total automation in sampling and quantification Automation Option

17 Background  Background through empty cell  Can cause fringing  Open beam background will shift spectrum  Can use separate cell One window instead of two Window is as thick as cell windows combined

18 Liquid Cell Trouble Shooting Too large of pathlength Good Spectrum

19 Liquid Cell Trouble Shooting Air in liquid cell fringing Good Spectrum

20 Quantitative Analysis  Quantitative results are very reproducible  Pathlength constant but can change due to wear - Needs to be monitored and compensated  Air bubbles are a problem  Benefit of automation makes cell ideal for large scale process control

21 Demountable Cell  Good for quantitative or qualitative analysis  Constant pathlength  Repairable  Variable configurations  Adjustable pathlength

22 Technique  Same technique used for filling and cleaning sealed cell  Benefit can change cell pathlength  Calculate pathlength on empty cell using interference fringes

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25 Quantitative Analysis  Quantitative results are reproducible  Pathlength variability  Window variability  Air bubbles are a problem as with sealed cells