AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

FOR ERP USE ONLY DO NOT DISTRIBUTE

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(b) Mobile phase B for CarboPac PA20, deionised water resistivity ≥18 MΩ.— Into an eluent

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bottle, introduce 2000 mL of water C(a) and degas with helium for 20 min. Thereafter

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protect the eluent from exposure to carbon dioxide until, and during use by suitable means

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(e.g. by keeping under a blanket of helium). Stable for 4 days at room temperature.

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(c) Mobile phase C for CarboPac PA20, sodium hydroxide solution (30 mM).— Into an eluent

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bottle, introduce 1000 mL of water C(a) and degas with helium for 20 min. Add (using a

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single-use plastic pipette) 1.6 mL of 50 % (w/w) NaOH solution C(j) . Degas with helium

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for 20 min and protect the eluent from exposure to carbon dioxide until, and during use by

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suitable means (e.g. by keeping under a blanket of helium). Stable for 1 week at room

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temperature.

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(d) Post-column addition reagent, sodium hydroxide solution (300 mM).— Into an eluent

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bottle, introduce 985 mL of water C(a) and add (using a single-use plastic pipette) 15.6 mL

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of 50 % (w/w) NaOH solution C(j) . Swirl the solution gently to mix and degas for 20 min.

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Stable for 1 month at room temperature, degas on day of use.

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F.

Mobile Phase Preparation (Using CarboPac PA1 column or Equivalent)

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If using a CarboPac PA20 column (or equivalent), skip this section.

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(a) Mobile phase A for CarboPac PA1, sodium hydroxide solution (200 mM).— Weigh

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1923 ± 2 g water C(a) into an eluent bottle and degas with helium for 20 min. Add 20 mL

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of 50 % (w/w) NaOH solution C(j) . Degas with helium for 20 min and protect the eluent

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from exposure to carbon dioxide until, and during use by suitable means (e.g. by keeping

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under a blanket of helium). Stable for 1 week at room temperature.

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(b) Mobile phase B for CarboPac PA1, deionised water resistivity ≥18 MΩ.— Fill a 2-L eluent

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bottle with 2000 mL water C(a) . Degas with helium for 20 min and protect the eluent from

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exposure to carbon dioxide until, and during use by suitable means (e.g. by keeping under

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a blanket of helium). Stable for 4 days at room temperature.

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