Question about spectrophotometry and resveratrol

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Discussion Overview

The discussion revolves around determining the concentration of resveratrol in a wine sample using spectrophotometry. Participants explore methods for creating a calibration curve and consider the implications of wine's complex composition on absorbance measurements.

Discussion Character

  • Homework-related, Technical explanation, Experimental/applied

Main Points Raised

  • One participant suggests creating an absorbance graph of known resveratrol concentrations in ethanol at 306 nm to compare against the wine sample's absorbance.
  • Another participant agrees with the graphing approach and recommends conducting three trials for each known concentration to ensure reliable standard deviation measurements.
  • A different participant raises a concern about the complexity of wine as a mixture, noting that other compounds may absorb at 306 nm and interfere with the results.
  • One participant advises using 12% ethanol in water for stock solutions instead of plain ethanol.

Areas of Agreement / Disagreement

Participants generally agree on the need to create a calibration curve using known concentrations of resveratrol, but there is a recognition of potential interference from other compounds in wine, indicating some uncertainty in the measurements.

Contextual Notes

The discussion does not resolve how to account for the interference from other compounds in wine or the specifics of the experimental setup beyond the suggestions made.

jackscholar
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Homework Statement


I need to determine the concentration of resveratrol in my sample of wine. How would i do this using spectrophotometry? I know it has an absorbance of 306nm in an ethonal solution, but I've only good wine. Do I create an absorbance graph of known resveratrol concentrations in ethanol at306nm and create a graph, then measure the absorbance of the wine and compare it to the graph?
 
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yes, I would definitely make a graph with different concentrations of resveratrol in ethanol, this will give you a good relantion between concentration and absorbance from there you can calculate the concentration of it. Also I would do 3 trials for each known concentration, just to make sure you are on the right standard diviation.
 
It's worth noting that wine is a complex mixture and could contain other compounds that could absorb at 306 nm and interfere with your measurements.
 
Use 12% ethanol in water for your stock solutions rather than plain ethanol.
 

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