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volumetric flask, dilute to volume with H
2
O, mix, and transfer to an
acid-washed polypropylene bottle.
(
h
)
Sampler wash solution, 1% HNO
3
.—Dilute 10 mL of trace
metal grade HNO
3
to 1000 mL with H
2
O.
H. Determination
Analyze test solutions using an ICP-OES instrument calibrated
with standard solutions. Insert a 10 mg/kg working standard or other
suitable quality control solution every 10 test portions, to monitor
for instrument drift. The inclusion of a digestion blank, a sample
duplicate, and known reference materials is highly encouraged.
I. Calculations
Element, mg / kg = (instrument concentration, mg / L)(100 mL)(1 L / 1000 mL)
(sample weight, g)(1 kg / 1000 g)
where 100mL assumes themicrowave digest is diluted to 100mL.
Reference:
J. AOAC Int. 89, 1447(2006).
ã
2009 AOAC INTERNATIONAL
AOAC Research Institute
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