Does anyone have a protocol for extracting chlorophyll-a from stream water? I had one I liked from years ago, but I can't find it... The one protocol I have now involves the use of nitrocellulose membranes. I was hoping to be able to use some form of Whatman filter paper instead. But, I'm open to suggestion. We've started a work-up of chemical parameters of the upper Paint Rock River in AL in conjunction with driftnet invert surveys, so far with alkalinity titrations, phosphate and ammonia tests. Alkalinity is pretty high (>200 mg/L), while phosphate and ammonia levels are barely detectable, all of which makes sense in this relatively pristine setting running over limestone and sandstone cobble. For July, 13 Orders of arthropods were identified in the driftnet catch, with 53% of the individuals being Odonates. So chl-a assays would be an interesting complement to this work on at least a seasonal basis.

With all that, thanks.

I came up with  Chlorophyll a.pdf   206.61KB   48 downloads.
Apparently there's a standard method,...if only you could find ISO: 10260, 1992

That's one I didn't find yesterday. It's a little scary, calling for an extraction in 90% ethanol at 75 deg. C. Time to live dangerously!

That's one I didn't find yesterday. It's a little scary, calling for an extraction in 90% ethanol at 75 deg. C. Time to live dangerously!

It's not dangerous if you have the proper equipment! All you need is a fume hood, the proper glassware, a good heating mantle with accurate controller and a fire extinguisher just in case!

Dean