Dear Sir,

I think formula for chlorophyll are different in different methods and it depends on the wave length at which your are taking the absorbance of your sample. Generally, for difference you can calculate p value and find the significant difference between a and b.

Thanking you,

There are different methods for the determination of chlorophylls a and b since the method of Arnon(1949). in my view the differences in the concentration of chlorophylls using different methods are negligible. so ,please do not worry about different methods at all.

Maybe the following papers would be interesting to you:

Porra, R., et al. (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." Biochimica et Biophysica Acta (BBA) - Bioenergetics 975(3): 384-394.

Lichtenthaler, H. K. and A. R. Wellburn (1985). "Determination of total carotenoids and chlorophylls a and b of leaf in different solvents." Biochemical Society Transactions 11: 591-592.

Muayed Fadhi Abbas  is the  right one.  One single 80% aqueous extract is enough and you can measure total chlorophyll, and chlorophylls a, and b with that ,following the well known method of Arnon (1949)

It depends on the method of extraction and specially the solvents used. However, a good method ha been published by  Porra, R., et al. (1989)

Dear Alp, I think this article would be helpful for you. Best wishes.