Hi Lorenzo

I think that I've used both.  As long as you wash it well so that there 
are no fine residues that won't centrifuge out, then it should be fine.

Hil



On 6/06/2021 11:24 am, Lorenzo Deprado wrote:
> Hi all,
>
> I am a PhD student from Florida International University and am in need of some guidance regarding replicating a phosphate isotope analysis methodology. I am looking to use the process laid out by McLaughlin et. al. in the 2004 paper titled "A precise method for the analysis of δ18O of dissolved inorganic phosphate in seawater" and the 2011 paper by Li et. al. titled "Isotopic evidence for the source and fate of phosphorus in Everglades wetland ecosystems".
>
> The method calls for use of "BIORAD AG 50×8 cation exchange resin". There are many options of mesh size for this product (20-50 to 200-400) and I am unsure on which to use. Does anyone have advice for picking the appropriate mesh size?
>
> Thank you,
>
> Lorenzo Deprado

-- 
Dr Hilary Stuart-Williams,

Stable Isotopes, Farquhar Lab,
Research School of Biology, R.N. Robertson Building (46),
The Australian National University, Canberra ACT 2601
Work: 61 02 6125 2099