REAGENTS:
1. Nitric acid, conc.*
2. Nitric acid, 5% (v/v). Add 50 mL conc. HNO3
to 500 mL water; dilute to 1 L.
3. Hydrogen peroxide, 30% H2O (w/w), reagent
grade.*
4. Calibration stock solution, 1000 µg/mL Pb.
Commercial standard or dissolve 1.00 g Pb
metal in minimum volume of HNO3
and dilute
to 1 L with 1% (v/v) HNO3
. Store in a
polyethylene bottle.
5. Matrix Modifier. Place 0.2 g NH4H2PO4
and
0.3 g Mg(NO3
)2
in a 100-mL volumetric flask.
Add 2 mL conc. HNO3
and bring to volume
with distilled or deionized water.
6. Argon, prepurified.
7. Distilled or deionized water.