Chlorophyll Analysis

[jboulton at TrentU.CA]

	Hi...

	I am looking for any suggestions on the best way to sample for 
Chlorophyll a.  I am looking at the amount of chlorophyll in a sand crust 
which was previously innoculated with different algae.  
	I have run across some problems trying to determine which is the 
best method (namely: solutuion) to use for breaking the cells which are 
bound to the sand grains.  I have been using DMSO4 + 90% acetone (1:4) 50 
ml blending in a waring blender for 4 min.s.  These are then filtered, and 
then analyzed for chlorophyll a.  
	The problem I am having (I think) is that during analysis, the 
volatile acetone isevaporating from the blank (control) cuvette, and thus 
changing the reference value of the test sample.  

	Any suggestions...  I have read two articles saying that DMSO4 + 
acetone is better and two that say that just acetone is accurate enough.  
Both have valid arguments and so I am at a loss as to which may be better.  

	Any suggestions or reference material would be of untold help...

	Thanx in advance.

		J. Wayne

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      JBOULTON at TRENTU.CA                        / |