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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(m) Membrane filter nylon. —0.2 µm, Ø 4.7 cm (only when using PA1 column for HPAEC-

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PAD).

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(n) Analytical column. —CarboPac PA20 (150 x 3 mm, 6.5 µm) with no guard, or CarboPac

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PA1 (250 x 2 mm, 10 µm), with PA1 guard (50 x 2 mm, 10 µm) (Thermo Fisher Scientific,

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MA USA), or equivalent.

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(o) Metal free liquid chromatograph consisting of :

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- Quaternary gradient pump able to deliver a flow of 0.5 mL/min (PA20) or 0.25 mL/min

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(PA1).

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- Helium degassing system.

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- Autosampler (cooling system recommended) able to inject 25 µL (PA20) or 20 µL (PA1).

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- Column compartment able to maintain a temperature of 30 °C (PA20) or 20 °C (PA1).

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- Electrochemical detector working in pulsed amperometric detection mode, equipped with

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a gold working electrode and an Ag/AgCl reference electrode (or equivalent).

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- Isocratic pump for post-column delivery, with pulse dampener, 125-µL reaction coil (or

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equivalent) and T-piece.

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- Data acquisition system.

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C.

Chemicals and Standards

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(a) Deionised Water. —Purified with resistivity ≥18 MΩ .

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(b) Maleic acid. —Puriss., ≥ 99.0 %.

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(c) Acetonitrile .—Gradient grade for liquid chromatography.

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(d) Acetic acid .—Glacial 100 % anhydrous, GR for analysis.

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(e) Potassium cyanohexaferrate(II)trihydrate .—[Optional].

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(f) Zinc acetate .—[Optional].

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(g) Trifluoroacetic acid (TFA) .—99 %.

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(h) Hydrochloric acid .—1 M .

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(i) Sodium acetate .—Anhydrous, ≥99.0 % (only when using PA1 column for HPAEC-PAD).

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