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If I have a sample of some compounds dissolved in water inside a glass vial (let's say quartz). Would it be possible to get a usable measurement through this glass vial without too much absorption by the glass itself?

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    $\begingroup$ Maybe Raman: spiedigitallibrary.org/conference-proceedings-of-spie/9995/… $\endgroup$ – Ed V Aug 2 '20 at 13:15
  • $\begingroup$ Why don´t you measure the empty vial? $\endgroup$ – Karl Aug 2 '20 at 17:37
  • $\begingroup$ Thank you for your answer. Let me try to rephrase my question. I HAVE to analyze a glass vial containing an aqueous solution. I am also using FT-Raman, but I was curious if it would make sense or not to use IR or FT-IR to analyze the content in the vial without opening it. Or if the glass or water would overlap the signals from the sample. I would like to conclude wether or not it contains e.g. m-cresol. $\endgroup$ – Tino Petersson Aug 3 '20 at 9:27
  • $\begingroup$ You can use ft Raman for your purpose. It works well. If you want to use IR,use AgCl liquid cell set up .you can use aq.solution. $\endgroup$ – Dr.K.S.Nagaraja Aug 13 '20 at 14:48
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As EdV said, when you have aqueous samples, Raman spectroscopy is the way to go. The problem is not the container (which should not be glass etc),the problem is water. Its absorption will hide the absorption of everything.

If you ever open an FTIR instruments, you will see that there is nothing which is made of glass or quartz because they absorb too strongly in the useful IR range.

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  • $\begingroup$ Thank you for your answer. Let me try to rephrase my question. I HAVE to analyze a glass vial containing an aqueous solution. I am also using FT-Raman, but I was curious if it would make sense or not to use IR or FT-IR to analyze the content in the vial without opening it. Or if the glass or water would overlap the signals from the sample. I would like to conclude wether or not it contains e.g. m-cresol. $\endgroup$ – Tino Petersson Aug 3 '20 at 9:27
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    $\begingroup$ If there is water and the container is made of glass, the absorption by these two components will be so strong that IR beam may not even cross the sample. You would have 0% transmittance and infinite absorbance. $\endgroup$ – M. Farooq Aug 3 '20 at 13:57
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    $\begingroup$ In short, there is no point in doing FTIR. $\endgroup$ – M. Farooq Aug 3 '20 at 14:11
  • $\begingroup$ Thank you very much for your replies. They are very appreciated. Just a bonus question; Would FT-Raman be usable? I only have access to FT-Raman equipment and not regular Raman. Would it be sensible to measure the samples through the glass vial? $\endgroup$ – Tino Petersson Aug 3 '20 at 15:48
  • $\begingroup$ FT-Raman is a very fancy instrument, it will work, why not? What you have to do it is to run the same container with water filled in and subtract this from the sample signal. $\endgroup$ – M. Farooq Aug 3 '20 at 16:07

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