Aluminium fluoride for industrial use — Determination of silica content — Spectrophotometric method ...
The method can be applied provided the phosphorus pentoxide content does not exceed 0,02 % (m/m). The principle is based on alkaline fusion of a test portion by means of a mixture of sodium carbonate and boric acid. Solution of the fused mass in excess nitric acid so that the pH of the final solution is between 0,3 and 0,5 after being diluted. Formation, in a suitable aliquot portion, of the (…
Formaldehyde solutions for industrial use — Determination of iron content — 2,2'- Bipyridyl pho...
The specified method is applicable to the detection of Fe contents less than 0,0004 % (m/m). The principle consists in conversion of any iron present into the sulphate by evaporation to dryness in the presence of sulphuric acid, and reduction of iron (III) by means of hydroxylammonium chloride. Formation of a iron (II) 2,2'-bipyridyl complex. Photometric measurement of the coloured complex…
Sulphuric acid and oleums for industrial use — Determination of oxides of nitrogen — 2,4- Xylenol sp...
The method ia applicable of oxide of nitrogen contents equal to or greater than 0,00002 % (m/m). The principle is based on oxidation of nitrous nitrogen to nitric nitrogen by potassium permanganate. Reaction of nitric nitrogen with 2,4-xylenol under specified conditions to form a nitrate derivate. Distillation of the nitrate derivate and absorption in sodium hydroxide solution. Spectrophotometric…
Liquid chlorine for industrial use — Determination of the content of chlorine by volume in the vapor...
The principle consists in sampling of a known volume of chlorine (about 100 ml) obtained by gasification of liquid chlorine. Absorption of the chlorine by a 2% zinc amalgam in the presence of 1 ml of saturated sodium chlorine solution. Measurement of the residual, non-condensable gases such as H2, O2, N2, CO, CO2, etc. Calculation of the volume of chlorine from the difference from total volume,…
Liquefied phenol for industrial use — Determination of phenols content — Bromination method
The method is not specific for phenol. It determines tho total amount of material that can be brominated under the conditions of the test. It is applicable to mixtures of about 80 % (V/V) phenol and 20 % (V/V) water. The principle is based on reaction between phenol and bromine from a measured amound of standard bromide/bromate solution. Formation of tribromophenol, follwed by iodometric…
Nitric acid for industrial use — Determination of iron content — 2,2'- Bipyridyl photometric me...
The method is applicable to the determination of iron contents greater than 0,0001 % (m/m). The principle consists in evaporation of a test portion, taking up by means of hydrochloric acid and reduction of iron(III) by means of hydroxylammonium chloride. Formation of iron(II)-2,2' -dipyridyl complex in ammonium acetate medium. Photometric measurement of the coloured complex at a wavelength…
Urea for industrial use — Determination of iron content — 2,2'- Bipyridyl photometric method
Describes a method applicable to iron contents greater than or equal to 0.00005 % (m/m). The principle is based on the ignition of the material at 800 °C and fusion of the residue with anhydrous potassium hydrogen sulphate. Solution of the cooled melt in hydrochloric acid and reduction of iron(III) by means of hydroxylammonium chloride. Formation of an iron(II)-2,2'bipyridyl complex in the…
Hydrochloric acid for industrial use — Determination of iron content — 2,2'- Bipyridyl spectrop...
The principle consists in evaporation of the test portion, taking up by means of hydrochloric acid and reduction of iron(III) by means of hydroxylammonium chloride. Formation of an iron(II)-2.2'-bipyridyl complex in a buffered medium at a pH value between 4.5 and 6. Photometric measurement of the coloured complex at a wavelength of about 522 nm.
Sulphuric acid and oleum for industrial use — Determination of iron content — 2,2'- Bipyridyl s...
The principle is based on evaporation of the test portion, taking up by means of hydrochloric acid and reduction of iron(III) by means of hydroxylammonium chloride. Formation of an iron(II) 2,2'-bipyridyl complex in a buffered medium at a pH value between 4.5 and 6. Spectrophotometric measurement of the coloured complex at a wavelength of about 522 nm. The method is applicable to the…
Sodium tripolyphosphate and sodium pyrophosphate for industrial use — Determination of iron content ...
Applicable to products having Fe contents of more than 0.001 % (m/m). Preliminary hydrolysis of polyphophates by prolonged boiling in the presence of hydrochloric acid. Reduction of iron(III) by means of hydroxylammonium chloride. Formation of the iron(II)-2,2'-dipyridyl complex in the presence of ammonium acetate at pH of 3.1 and a temperature of 75 °C (under the test conditions the…
