Will it affect the amount of chlorophyll yield? This is because I tried with dried samples and the yield is very low. My aim is to extract its pigments. How about for other kind of harder samples such as turmeric?
No, you cannot. Chlorophyll will be broken down during drying, which you must have noticed with your naked eye.
I agree with Hans Lambers, during drying Chlorophyll will be degraded into Pheophytin giving the green-brown tone that you can observe from your samples. The only drying method that allows and is required to use for pigment determination in order to eliminate the leaf water content is freeze-drying.
Thank you. How about using fresh leaves? Would it be better compared to freeze-dried leaves? Another thing is wouldn't the heat from the repetitive soxhlet extraction degrade the chlorophyll?
Fresh leaves is absolutely fine. I would recommend it.
Do consult an original reference that describes the exact technique to avoid any pitfalls.
Holden, M. 1976. Chlorophylls. In: Chemistry and Biochemistry of Plant Pigments, Vol. 2 (Ed, Goodwin, T. W.) Academic Press, London, pp. 1-37.
Lichtenthaler, H.K. 1987. Chlorophylls and carotenoids: Pigments of photosynthetic biomembranes. In: Methods in Enzymology, Pacher, L. & Douce, R. (eds.), Academic Press, New York, 148:35-382.
Porra, R.J., Thompson, W.A., and Kriedemann, P.E. 1989. Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: Verification of the concentration of chlorophyll standards by atomic absorption spectroscopy. Biochim. Biophys. Acta 975: 384-394
Wellburn, A.R. 1994. The spectral determination of chlorophylls a and b, as well as ttal carotenoids, using various solvents with spectrophotometers of different resolution. J. Plant Physiol. 144: 307-313.
Allow me to add something tpo what Hans Lambers said. Depending on the water content of the leaves using them fresh can be or not a problem. If the water content is very low there is no problem but if the water content is high it will modify the final extraction solvent percentage an therefore the peaks of absorption as well as the molar extinction coefficients will suffer shifts since they are dependent on the extraction solvent type and dilution. This is why I always advice to use freeze-dried leafs.
The moisture content is at about 86%. I think I'll go with freeze drying. Then I will follow Schwartz and Lorenzo's method of grinding the leaves with excess solvent and filtering it. Thanks Hans and Bernardo!
Check similar threads on Rg and other publications:
http://www.slideshare.net/rahulbs89/extraction-of-plant-contituents
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