For production of paper packages the sheet of paper of 1515 cm in size is put on a diagonal in half and edges bend in one party on 1 cm. When determining water in fat tests (a herring, etc.) in a paper package place in addition the sheet of filter paper.
In two conic flasks select on 10 — 25 cm3 of a filtrate (50 cm3 — in the analysis of a fodder flour) and titrut solution of nitrate silver 0,1 mol/dm3 in the presence of 3 — 4 drops of solution of hromovokisly potassium of 100 g/dm3 (10% - a foot) or 1 drops of saturated solution before receiving not disappearing reddish-brown coloring.
Distillate is transferred to a measured flask with a capacity of 50 cm3, wash away a reception test tube and diluted with the distilled water to 3/4 volumes of a flask. At the same time in three measured flasks with a capacity of 50 cm3 select 5, 10 and 25 cm3 of working standard solution of chloride ammonium and add bezammiachny water to 3/4, their volume.
For fish and other products capable at drying to bake in dense weight, previously bring 5 — 10 g of sand in a byuksa and carefully mix a hinge plate of a product. Quartz sand is cleared previously as follows: wash out tap clear water, fill in with solution of hydrochloric acid (1: for days, carefully wash out the water, and then distilled water before disappearance of sour reaction to litmus, dry up, calcinate and sift.
Solutions leave alone for 10 — 15 min. then determine optical density by the photoelectrocolorimeter at the wavelength of 400 nanometers in ditches with a working length of 10 mm in relation to control solution.
Take an arithmetic average for final result value of results of two parallel definitions, the allowed divergences between which should not exceed 0,001%. Calculations will see to the third decimal sign.