SPSFAM Heavy Metals ERP Book

AOAC Expert Review Panel for Heavy Metals AOAC OMA Final Action Requirements for 2016.04 Method Author Response

• 4.10.3- More descriptive

o Safety considerations: o See below edits:

o Use appropriate personal protective equipment (including safety glasses, gloves, and a laboratory coat) when handling standards (powders and/or concentrated solutions ) containing toxic arsenic compounds. Additionally, proper ventilation and other physical safeguards should be in place when handling said compounds. Ammonium hydroxide is caustic and should also be handled in the same manner. Analysts should consult and must be familiar with their laboratory’s chemical hygiene and safety plan and Safety Data Sheets for all reagents and standards listed. Refer to instrument manuals for safety precautions regarding use. All waste generated must be handled and disposed of appropriately. • List of equipment include a refractometer measuring brix if determining juice concentrate. o Refractometer .— Reichert AR200 Digital Refractometer, (Reichert Ophthalmic Instruments, Buffalo, New York, USA) • 4.10, table 2. Provide a range for the helium flow rate. o Range of 1.5 to 3 mL/min was added. • Instrument setup – add paragraph on instrument tuning. o Follow instrument manufacturer recommendations standard operating procedure for startup and initialization. After a ~30 min warm-up, ensure that tune the ICP–MS is operating normally and tune the instrument for use with helium as a collision cell gas. In general, the helium flow rate should be optimized to minimize polyatomic interferences, while preserving m/z 75 signal., checking that performance meets the default specifications. For a given ICP–MS instrument, it is recommended that the He gas flow rate for chromatographic analysis be 2–3 mL/min less than what is used for typical total arsenic analys ei s using He mode , therefore using ~1.5-3.0 mL/min, with default value of 2 mL/min . • Measurement of LOD/LOQ needs clarification. Report LOQ using multiplication factor 10 instead of FDA factor 30 to align with AOAC. o Text in the caption of Table 2016.04A and footnotes changed to include AOAC calculation and FDA calculation for ASQL and LOQ. • Analytical range should be included in method. o Added at the end of Calculation section. o The analytical working range is from the LOD (0.25 ng/g for RTD, 1.5 ng/g for concentrate) to the maximum calibration point (10 ng/g) adjusted for the dilution factor (50 ng/g for RTD, 300 ng/g for concentrate) • Robustness data for mobile phase pH range. o No significant shifts we noted at pH range 7.75 to 8.75. Data available upon request. • Precautionary statement needed around pH and co-elution and check reagents for contamination prior to use. o A note was added at the end of the QC Elements section: o Note: Due to varying pH differences of samples, analyte peaks may exhibit retention time shifts, possibly leading to peak overlap or a mismatch compared standard chromatograms. To identify peaks, additions of standards to the samples is

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