to produce samples with stable white phospho-

Next we tried spiking matrices that were po-

rus concentrations, we decided to spike wet soils

tentially less reactive then the soil used in previ-

with white phosphorus dissolved in an organic

ous samples. These matrices were wet sand and

solvent. Solutions of white phosphorus in solvents

glass microbeads. After almost two weeks of stor-

such as toluene and isooctane are stable for years.

age in 22-mL vials (no headspace), no significant

We chose mineral oil , a solvent that has high solu-

loss was noted for the spiked glass microbeads

bility for white phosphorus (12 g/L) (Stich 1953)

(Table 2f). While concentrations in the spiked sand

and has low volatility (for safety during flame-

were less than day 0, loss was smaller than that

sealing of ampoules ). We spiked 19 g of wet soil

observed for the AEC soil.

with 0.18 g of white phosphorus dissolved in

Finally, we spiked wet glass microbeads stored

mineral oil (25 L of a 7.2-mg/L solution), and

in 120-mL jars, the same jars used for sample ex-

stored the soils in ampoules with and without ni-

traction. After 14 days of storage at room tempera-