AOAC SPIFAN Nutrients ERP (December 7, 2022)

For ERP/Working Group Use Only DO NOT DISTRIBUTE Fluor-04 (SLV) Resubmission FOR ERP USE ONLY DO NOT DISTRIBUTE

C. APPARATUS

1. General Laboratory Equipment a) Analytical Balance, precision 0.0001 g b) Top loading balance, precision 0.1 g c) Magnetic stirrer with insulated surface

d) 100 mL class A volumetric flasks - plastic e) 1000 mL class A volumetric flasks - plastic f) 1, 2, 4, 6, 8, 10, 20, 30, and 50 mL class A pipettes g) Teflon coated stir bars

h) Plastic beakers or cups 125 mL (or equivalent) i) 50 mL Brinkman Dispensette (or equivalent) j) 10 mL Brinkman Dispensette (or equivalent) k) Laboratory timer 2. Instrumentation a) Ion analyzer (Mettler ‘SevenExcellence’ model S470 ion meter or equivalent) equipped with uMix magnetic stirrer (if possible) b) Fluoride electrode, Mettler perfection combination fluoride electrode, Orion Model 9609BN, or equivalent D. CHEMICALS/STANDARDS Notes: Unless otherwise noted, store the following chemicals at room temperature. Any reagent must be prepared fresh when contamination or decomposition is suspected . 1. Standards a) 100 ppm Fluoride, NIST traceable, ORION 940907 or equivalent 2. Reagents a) Electrode filling solution, as specified by vendor

b) Sodium citrate dihydrate, ACS reagent grade or equivalent c) 37% hydrochloric acid, ACS reagent grade or equivalent

3. Solutions a) 1M Sodium Citrate : Weigh 588 g of sodium citrate dihydrate into a 2000 mL volumetric flask. Add approximately 1800 mL laboratory water. Stir until the salt is dissolved. Bring to volume with laboratory water. Expiration: 6 months.

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