AOAC RI ERP EBOOK FOR FERTILIZERS

for instrument drift. The inclusion of a digestion blank, a sample duplicate, and known reference materials is highly encouraged. I. Calculations

volumetric flask, dilute to volume with H 2 acid-washed polypropylene bottle. ( h ) Sampler wash solution, 1% HNO 3

O, mix, and transfer to an

.—Dilute 10 mL of trace

metal grade HNO 3

to 1000 mL with H 2

O.

Element, mg / kg = (instrument concentration, mg / L)(100 mL)(1 L / 1000 mL) (sample weight, g)(1 kg / 1000 g)

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

where 100mL assumes themicrowave digest is diluted to 100mL. Reference: J. AOAC Int. 89, 1447(2006) .

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