Codex STAN 234 Working Group-Method Reviews 1-23-18

should be used for calibration will depend on computer software requirements of particular ICP system in use. After calibration is complete, analyze test solutions. Check calibration of instrument after every 10 tests by analyzing calibration standards. If reanalysis of calibration standards indicates that instrument has drifted out of calibration (>3% of original values), recalibrate instrument. Computer will calculate concentration for each element of each diluted test solution as µ g/mL. Use following equation to convert

this value to µ g/mL if original test portion was ready-to-feed or concentrated formula or µ g/g if test portion was powder.

C = A × (50 mL/ B )

where A = concentration ( µ g/mL) of element as determined by ICP; B = volume or weight of test portion as mL or g; C = elemental concentration in test solution, µ g/mL or µ g/g, depending on value of B . Reference: JAOAC 67, 985(1984).

 2005 AOAC INTERNATIONAL