OMB Meeting Book - Jan. 11, 2018

2016.03 (Nov. 2017) - Chlor-02/04 Final Action Review FOR ERP USE ONLY DO NOT DISTRIBUTE

titrator does not have a build-in rod stirrer). Place the autosampler cup or beaker onto a magnetic stirrer and stir until dissolved or finely suspended.

(h).The pH of the test solution shall be below 1.5, In case of any doubts, check by means of a pH-meter and, if necessary, add a little more nitric acid solution (D. e).

G.

INSTRUMENT OPERATING CONDITIONS

(a). Check and maintenance of the combined silver electrode

Rinse electrode with deionized water and wipe before use. Renew the electrolyte c = 1 mol/l KNO 3 (D. i) periodically per manufacturer’s recommendations. If fat sticks to the electrodes during a series of analyses, then eliminate it by briefly immersing the electrode in acetone. Store the silver electrode in KNO 3 solution (D. i) after appropriate cleaning. NOTE Instead of the combined silver electrode, separate silver and reference electrodes may also be used. Connect the combined silver electrode to the titration apparatus, according to the manufacturer's indications. Ensure that the titration vessels are correctly placed on the autosampler and there are enough reagents, both nitric acid solution (if added automatically) (D. e) and silver nitrate solution (C. g or D. a). If no autosampler is available, place the sample solutions manually under the titration equipment. (b). Titration

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