Using Fluorescence Spectroscopy to Determine the Chlorophyll C
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Transcript Using Fluorescence Spectroscopy to Determine the Chlorophyll C
Using Fluorescence Spectroscopy to
Determine the Relative Chlorophyll
Concentrations of Vegetables
Jane Kim & Rebecca Long
Ch251B – Instrumental Analysis Lab
Professor A. Newmark
Background – Why Chlorophyll?
• Health benefits in chlorophyll:
- Blocks absorption of carcinogens
- Helps regenerate blood
- Prevents bad breath and body odors
- Promotes wound healing
Solution Analyzed - Chlorophyll extract
• Chlorophyll extract: contained a combination
of several kinds of chlorophyll, most likely
majority was chlorophyll a (most prevalent)
Chlorophyll c1
Chlorophyll a
Chlorophyll b
Chlorophyll d
Chlorophyll c2
Experimental
1. Ground vegetables in acetone and water
2. Added hexane
3. Mixed thoroughly
4. Let stand for layers to form
5. Extracted hexane layer chlorophyll extract
6. Analyzed extracts using fluorescence
spectrophotometer
Results
• Gopal et al. reported chlorophyll fluorescence
peak at ≈ 660 nm
Figure 1. Fluorescence absorption spectrum of chlorophyll
• Our fluorescence spectra peaks occurred at
similar wavelengths ✔
Results
• Beer’s Law: A = ebc,
(A = absorbance, e = molar absorbtivity, b = path length of sample, c = concentration
of compound in solution)
Absorbance of chlorophyll α Concentration of chlorophyll
• Order of Relative Chlorophyll Concentrations:
spinach > broccoli rabe > cilantro > broccoli > cauliflower
Fluorescence Absorption Spectra of All Samples
Fluorescence Absorbances
Conclusions
• Eating spinach provides the greatest chlorophyll
health benefits
• Confirmed! – The degree of the vegetable’s green
color corresponds to the concentration of chlorophyll
• Plant structure confirms chlorophyll concentration