The Separation of Beryllium from Spectral Interfering Elements in Inductively Coupled Plasma – Atomic Emission Spectroscopic Analysis Daniel R. McAlister and E. Philip Horwitz PG Research Foundation, Inc S Cass Avenue, Suite 109 Darien, IL 60561

Problems with Current Method Interfering elements in the AES spectrum of Beryllium Beryllium lines very intense  method is very sensitive for the determination of beryllium Interfering lines from other elements could lead to false positives.

Uptake of Selected Elements on Dipex Resin Several EXC materials evaluated Dipex offered the most promising beryllium retention characteristics

Uptake of Selected Elements on Dipex Resin Single column should remove all ICP-AES interferences Load pH 2-4 Rinse 0.2 M HNO 3 Strip Be with 4 M HNO 3 Potential for 2-10 x concentration of Be depending on sample size

Uptake of Selected Elements on Dipex Resin Resin selective for Be over other alkaline earth metal ions Ca and Mg common matrix impurities

Uptake of Selected Elements on Dipex Resin Fe(III) strongly retained Al(III) and Pb(II) have similar retention to Be(II) Cu(II) more weakly retained Large amounts of Fe(III) could interfere with Be(II) uptake

Uptake of Selected Elements on Dipex Resin Resin selectively retains Be(II) over most other divalent metal ions Be(II) can be separated from samples containing large quantities of divalent metal ion impurities

Proposed Method for Beryllium Purification Prepare samples as before (Digest with H 2 SO 4 /H 2 O 2, dilute with HNO 3 ) Neutralize samples to pH 1-2 with sodium aceate Buffers to maximum pH of 4.5 Monitor pH with methyl violet or crystal violet or pH strip pH Range over which separation is effective

Elution of Be and Selected Elements on Dipex Resin

Simulated Sample Results Successfully separated Be from samples digested with H 2 SO 4 /H 2 O 2 Several different digested methods employed in Be analyses (HCl, H 2 SO 4, HNO 3, HF, H 2 O 2, HClO 4 ) High levels of impurities

Digestion Methods using HF

Separation of Be from Large Amounts of Interferences

Uptake of Selected Metal Ions on LN2 and LN3 Resins U(VI), Th(IV), Ti(IV) retained from all [HNO 3 ] LN2: Strongly retains Fe(III) LN3: Be not retained from pH < 2 Choice of LN2/LN3 depends on desired operating conditions and amount of Fe in samples

Elution of Be on LN2 and LN3 Guard Columns

Effect of Large Quantities of Uranium LN2 and LN3 Resins effectively increase the capacity for Uranium With LN2, the GC remains connected through the load, rinse and strip With LN3, the GC can be removed following the rinse

Conclusions Efficient, Reliable method for purifying Be from all ICP-AES spectral interfering elements has been found using a single column Method is compatible with current monitoring and sample digestion methods Method is robust and performs over a wide pH range Inserting a LN2 or LN3 Resin guard column increases U capacity without changing the chemistry or significantly decreasing Be yields. Working to develop methods to isolate Be from high levels of other impurities