long time since I have heard from you.
Sb like several elements B, Zn, Ag are usually "sticky" & are retained on the torch. Many years ago, I used lower cal stds when looking at low levels, but I guess you cannot do that with such high concs in solution.
Another problem is of course that the torch is in a horizontal orientation for axial & this would make the problem worse, than for a vertical radial orientation.
Something in the mine samples is stripping off the Sb quicker than the simple samples & stds. maybe try experimenting with matrix elements or compounds (PO4 / SO4 / SO3 ??)
Geoff TYLER still in Paris
De : Gerry Grady <[log in to unmask]>
A : [log in to unmask]
Envoyé le : Mardi, 19 Janvier 2010 22:43
Sujet : Sb Antimony carryover in ICP-OES
I have an application query from a customer lab regarding unusual
behaviour of Antimony in ICP-OES analysis.
In summary it appears that Antimony exhibits carryover when in simple
Sample & Standard matrices (e.g. 1%HNO3), but washes out quickly & has
excellent RSD's in a more complex sample solution (in this case a
wastewater sample from a base metal mine with about 1000ppm dissolved
Sb concentrations are in the region of 100 ug/L.
I have heard that adding tartaric acid is the key to solving this Sb
stability/ mobility problem, but would welcome any specific advice.
Instrument is a Varian 720 AX.
Many thanks for an comment!
Varian ICP Sales
JVA Analytical Ltd