i have grown microalgae in flasks at vary concentrations of heavy metals such as Cd and Pb....so i have to know how much cells are utilising it for their metabolism and also which oxidation number of metal is toxic to cells...
Seems a quite complex problem to study. Total uptake can be probably estimated by analysis of the microalgae after contact with the heavy metal ions, and further separation (ultracentrifugation, ultrafiltration, ...). But probably you will measure not only uptaken heavy metals, you will also measure heavy metals adsorbed on the microalgae. You will need some kind of soft leaching (probably acid) to separate adsorbed heavy metals. These kind of interactions have been the subject of intense research, try a search. There are specific journals, like Biological Trace Element Research (Springer). Good luck.
Dear Shabana,
I would try using ion selective electrodes. To distinct between adsorption and metabolic activity (arbitrarily) I would do adsorption measurements with short contact time.
Measuring the Cd/ or Pb metal concentration is the only way to determine its uptake by the plant.
As far as oxidation state is concerned both the elements have only one oxidation state that +2, SoNo uncertainity about it.
Analytical technique employed will depend on the amount of element present ( its concentration) in the solution. You may use AAS or Anodic stripping voltametry for sensitive determination of residual metal present in the matrix. Remember that you need to brisk off the algae to push away loosely sorbed metal ions on the surface of algae; the metal uptaken by algae will never get detach metal by any physical force. Hence modest sonication of the sample followed by centrifugation would yield precise quantity of metal not uptaken by Algae
I might be over-simplifying this but why not just draw a sample from the aqueous phase with a syringe and then use a syringe filter to eliminate any solids? This would yield a sample ready to be analysed with AAS for metal concentrations(for example). Sampling would be straight-forward and fast.
My dear Riina Salmimies
See what Eduardo Pinillla Gil, answers in tune with what I said: "You will need some kind of soft leaching (probably acid) to separate adsorbed heavy metals. and what I said is
"Hence modest sonication of the sample followed by centrifugation would yield precise quantity of metal not uptaken by Algae"
My dear you are in no way, thinking of metal ions sorbed on surface of algae. No syringe filtration can remove the sorbed metal ions. from algae surfaces....
I advise you never to go so straightforward... when you dont have prior knowledge of sorption behaviour of metal ions in contact with Solid matrices.
Or else u may never arrive at logical conclusion through analysis. A Clean Separation of target analyte from complex sample matrices is THE KEY to Good Analytical Chemistry -
Remember this for doing Good meaningful Chemistry or biochemistry
Indeed, I'm not considering adsorbtion because that was not referred to in the original question nor has Ms Khan commented on the matter after it has been brought up. If you read through my suggestion again, you will find that I was in no way suggesting that syringe filtration could remove metals attached to the surface of the algae. With respect, I don't agree with what you say about simplicity not being a good way of doing things. Very often the most simple solutions can be the best ones as complicating things can result in larger error. There's no need for you to criticize my knowledge as this was only a suggestion based on the original question.
Riina No one can claim complete knowledge in this world. Yet one must assume all situations for sample handling. You should know that there so many anaytical methods being developed yet there still exist scope for more . New analytcail challenges face the world mostly due to never-heard sample matrices and Crux of the new analytical developments lies in simple easy sample clean-up strategies adopted for the enrichment of target analyte that s why I quoted suggestions of Eduardo Pinillla Gil... "The more the number support you approaches more you win support for your knowledge" . No need to grumble here. Every Analytical chemist must look and read following links to upgrade the knowldege...
some are given below
http://www.sepscienceasia.com/Conferences/Separation-Science-Europe-2011/Programme
http://www.intechopen.com/articles/show/title/modern-sample-preparation-techniques-for-pesticide-analysis
http://www.sepscienceasia.com/Conferences/Separation-Science-Europe-2011/Programme
Sample preparation for accurate analysis
http://www.foss.dk/industry-solution/chemical-analysis/sample-preparation?gclid=CL66zLnGq6wCFYUfpAodXkPf2g
All the best.
You must be having great knowledge.. Pls keep sending all your analytical science papers tome i willl readt hem carefully to upgrade my knowledge. Best wishes and Regards
u may correspond with me on [email protected]
Thanks all for the reply......it has helped me with all the information given in this post...... .as i have just begun with this work so i m going to try with simple ways at this stage....basically as it deals with heavy metal uptake so the question of adsorption does come into it and also how much goes in metabolism of cells.....
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