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Questions tagged [polarimetry]

For question about the interaction of light polarization with matter.

0 votes
1 answer
53 views

Fluorochrome (fluorescein) emission decay when linked to macromolecule

I measure the intensity and polarization of light emitted from a blood sample that contains excited fluorescein (experiment known as fluorescence polarization assay). The excitation is done, as usual, ...
nicolas005's user avatar
0 votes
0 answers
40 views

Why can't an "upside down" chiral molecule neutralize the polarized light effect? [duplicate]

Steve Mould did a nice video a few months back called "Why Sugar Always Twists Light To The Right" (link is timestamped at the critical part). However his explanation was not complete. He ...
CodyBugstein's user avatar
10 votes
2 answers
669 views

Do isotopic groups cause optical activity?

I understood the simplified reason for optical activity of a compound based on the difference in the angular velocities of counter-rotating circularly polarized light. The difference is due to the ...
Vishnu's user avatar
  • 2,080
4 votes
1 answer
2k views

Why is only monochromatic light used in polarimeter?

While using the polarimeter to determine optical rotation, why can't we use polychromatic light? What would change?
user_9's user avatar
  • 203
1 vote
1 answer
631 views

Is specific rotation defined for mixtures of enantiomers or meso compounds?

I recently had to do an experiment where we had to make a racemic mixture of D and L complexes and then resolve the enantiomers, and measure the optical rotation of the racemic mixture, and the ...
S R Maiti's user avatar
  • 5,685
1 vote
1 answer
1k views

What are some ways to measure sugar concentration of fruits? [closed]

I've tried to do titrations using the quantitative Benedict's Solution and it was difficult to use as I do not have a way of keeping a constant temperature. I am currently using a Polarimeter to find ...
Amy W.'s user avatar
  • 11
4 votes
1 answer
1k views

Why left and right circularly polarized light have different index of refraction in chiral media?

This is a followup question of (Dependence of the angle of rotation on the wavelength of plane polarized light). Ron's answer tells about the difference between left and right circularly polarized ...
Mockingbird's user avatar
  • 2,331
4 votes
2 answers
6k views

Dependence of the angle of rotation on the wavelength of plane polarized light

Wavelength difference is a big deal, I know. It can solely change the whole interaction between the chiral molecule & the light. But I am not sure what's the mechanism by which light of different ...
Mockingbird's user avatar
  • 2,331
8 votes
1 answer
507 views

Discovery of optical activity of enantiomers - where did the idea of using polarized light came from?

According to Wikipedia, optical activity was first observed in 1811 in quartz. Louis Pasteur's contribution is also mentioned there and in other sources as a major advancement in establishing optical ...
Don_S's user avatar
  • 1,410
5 votes
1 answer
208 views

Polarimetry test for cholesterol?

If I have a pure substance which may be cholesterol can I test that by polarimetry? In other words the idea would be to dissolve the sample in dichloromethane or ethanol, then test the rotation using ...
Shaka Boom's user avatar
  • 2,344
3 votes
1 answer
947 views

How are the two formulas for enantiomeric excess/optical purity equal?

I’ve been given two formulas to use for enantiomeric excess or optical purity: $$\frac{\text{observed rotation}}{\text{specific rotation of pure enantiomer}}\:\:\:\:\:\times\:100\%\tag{1}$$ $$\frac{|d-...
lightweaver's user avatar
  • 1,529