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+ Solvent effect
+ Solvents
+ Uv-visible spectroscopy
+ Acetic acid
+ Spectroscopy
+ Uv spectrophotometer
Posted by
Laurence Stein

Why do different solvents affect UV-vis spectroscopy?

Charles Foy  Follow

phosphate buffered saline has a pH of 7.4.
Glacial Acetic acid has a pH of 2.4
PBS is highly ionic.
Solvents may change the conformation by hydrogen bonding, solvation and protonation etc. This changes the spectra.
Maybe and interesting book for you:
Solvents and Solvent Effects in Organic Chemistry

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David Dowler  Follow

Th two eanswers given are good. if more info is needed let me know.

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Claudio Giomini  Follow

phosphate buffered saline has a pH of 7.4.
Glacial Acetic acid has a pH of 2.4
PBS is highly ionic.
Solvents may change the conformation by hydrogen bonding, solvation and protonation etc. This changes the spectra.
Maybe and interesting book for you:
Solvents and Solvent Effects in Organic Chemistry

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Alex Rodrigo  Follow

Dear Olivia,
you posted a bad formulated question. Why??
At first :
- please define the kind of peptide
- please define the pH of your buffer (according to the preparation of it, the pH can be from 5.8 to 7.8/define the mixture of your precalculated amounts of monobasic and dibasic phosphates)
- please define the % of your acetic acid and purity.
- please note that water of PBS has a cut off like acetic acid (see google/ cut off in spectroscopy).
- What a kind of spectrometer are you using? single or dual beam or diodes array?
- please send us a picture of your spectrum or spectra

Thank you in advance.

JRG
-

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David Jones  Follow

Hi Olivia,
Solvent can affect the UV- Visible spectrum for a compound. The different solvent can causes red shift or blue shift depending on polarity of solvent and type of chromofor if it is pi- pi transition or n- pi transition.

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