1. Metals Subgroup Agenda
Metals subgroup membership
3 metals methods chosen for AOAC Pilot Project
Nutritional Elements in Foods by ICP-AES – Improvement of AOAC OMA Method
As, Cd, Pb, Hg in Foods by ICP-MS – NMKL Interlaboratory Study
Inorganic As in Rice by IC-ICP-MS
NMKL and EU information on metals methods – Lars
Voting members needed for community and metals experts for method reviews
SLV document

2. 5. SLV Document Introduction Definitions Performance criteria
Should we provide in guidance document? Should we simply reference some sources?
Performance characteristics
Some are method development, some are validation – how do you feel about them being intermingled?
Technical guidelines and approaches
Representative analytes and representative species – do you agree with this approach?

3. Analytical range and linearity Matrix effects – 2 scenarios
6 standards injected over expected concentration range
Matrix effects – 2 scenarios
Blank matrix, no blank matrix, greater than 10% difference in the slopes?
LOD/LOQ – 3 approaches
Evaluation of background noise, y-intercept approach, spiking experiments
How do we want to calculate? Method blank vs blank matrix?
Reps, days?
Method recovery – 4 scenarios
Blk matrix with target ML – 0.5ML, 1ML, 2ML
Blk matrix with no target ML – 3LOD, 10LOD, upper limit of range
No blk matrix with target ML – 0.5ML, 1ML, 2ML –
No blk matrix with no target ML – 0.5X, 1X, 2X (or higher) of characterized concentration in matrix
Levels, reps, days?

4. Instrument repeatability Method repeatability
Inject cal curves 5 times in random order in one run
Method repeatability
Prepare pools of materials equivalent levels used in recovery studies
Reps, levels, days
Intermediate precision
Same experiment as method repeatability study with different analyst and different instrumentation (if possible)
Measurement Uncertainty – use data gathered in validation to calculate
Ruggedness – Youden’s factorial approach
Example of SLV experimental design
Other
Calculations?