hello

The concentration of heavy metals is measured using the atomic spectral absorption device

regards

Hi there

You would normally homogenise the sample in the same way as you described it. Then you can digest the whole lot to get the total metal concentration in your sediment.

In order to analise other different size fractions, you just need to justify why you are doing it and what do you expect to achieve from this (eg, if you are interested in sand, clay slit, etc)

As long as you report the method used, you should be OK

I hope this helps

Thank you Dr. Munoz, let say I'm interested in the effects of heavy metals in sediment to the annelids, how would that decide if I need to further sieve my samples or not?

Why wouldn't you be doing particle size analysis from the front end to the back end of the annelid, in the soils of investigation to find out? Annelids concentrate metals in casts, and depending on the level of bioturbation top layers can be concentrated in metals. So you will be analysing the fractions to begin and at the end in the soil, and comparing total strata zoned metal contents, and matching the annelids metal content in different settings with a biomass metal reconciliation.

Dear Chee,

Read the attached two papers. You may get answers of your questions.

Best wishes

Hello,

Sediment size points you to different targets.

- Total sediment (crushed or not) includes large particles of mineral origine and their composition is related to local geology.

- Fine fraction is, usually, composed by laminar minerals (clays) and autochthonous precipitated materials. They can accumulate metals and can be employed as pollution indicators.