OMB Meeting Book - Jan. 11, 2018

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

(c) Precipitating solution (Carrez) I.

Weigh 106 g potassium ferrocyanide trihydrate, (C. d) dissolve in an appropriate amount of water and transfer into a 1000 ml volumetric flask. Make up to the mark using water. Mix well.

(d) Precipitating solution (Carrez) II.

Weigh 220 g zinc acetate dihydrate (C. e) and transfer into a 1000 ml volumetric flask. Dissolve with an appropriate amount of water, and add 30 ml glacial acetic acid. Make up to the mark using water. Mix well.

(e) Nitric acid solution, c = 4 mol/l.

With care, add 100 ml concentrated nitric acid (C. f) to 300 ml water. Mix well.

(f) Wash solution.

According to autosampler/titrator manufacturer’s instructions, (e.g. acetone, nitric acid solution (D. e), or other).

(g) AgNO 3 solution, c = 0,025 mol/l (optional).

Into a 1 000 ml volumetric flask, pipet 250 ml AgNO 3 solution, 0,1 mol/l (C. g) or (D. a). Make up to the mark with water. Prepare freshly before use. Then check the titer by titration of 25 ml against 0,025 mol/l NaCl solution.

(h) NaCl solution, c = 0,025 mol/l (optional).

Into a 100 ml volumetric flask pipet 25 ml NaCl solution, 0,1 mol/l (C .h or D. b). Make up to the mark with water. Prepare freshly before use.

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