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The sodium hydroxide bound as aluminate and titrated in the p-value determination is calculated by subsequent determination of the aluminum and deducted, as it is no longer available for purification.

The aluminum determination itself is based on the reaction between aluminum hydroxide and sodium fluoride, in which sodium hydroxide is released and thus serves as a measure for calculating the aluminum.

Carbonates interfering with the titration are precipitated with Ba²⁺ ions.

The aliquot of an extract of malt is added to a buffered starch solution and allowed to stand for exactly 30 min at 20 °C. Then, the maltose – formed primarily from the starch through the action of the β-amylase – is measured using iodine and is determined according to the following chemical reaction:

The analysis involves a reaction with N,N-diethyl-1,4-phenylenediamine (DPD), which forms a compound possessing a red color at a pH of 6.2–6.5. The solution is titrated with an ammonium iron(II) sulfate standard solution until the red color disappears. Total chlorine is measured through the addition of potassium iodide, of which a known amount in excess of that required is added to the solution in advance.

The analysis involves a reaction with N,N-diethyl-1,4-phenylenediamine (DPD), which forms a compound possessing a red color at a pH of 6.2–6.5. In this reaction, chlorine dioxide is reduced to a single chlorite ion. The solution is titrated with an ammonium iron(II) sulfate solution until the red color disappears. The chlorine dioxide concentration in the water sample is calculated on the basis of the quantity of ammonium iron(II) sulfate solution consumed in the titration. The formation of the red color due to the addition of DPD can take place in the presence of other compounds other than chlorine dioxide. The oxidation reaction can be brought about by any oxidizing agent and is dependent upon the redox potential and the concentration of the solution.

Through the addition of a sodium hydroxide solution, the carbon dioxide in beer becomes bound as sodium hydrogen carbonate or sodium carbonate. Sulfuric acid is added to an aliquot of the beer treated with sodium hydroxide. This causes the carbon dioxide to be released again, after which a stream of air conducts the carbon dioxide into a barium hydroxide solution. Through titration of the excess barium hydroxide, the carbon dioxide content of the beer can be determined [1].

Determination of the quicklime (CaO) or sodium hydroxide (NaOH) content of the detergent solution with an acid solution (HCl or H₂SO₄) with corresponding equivalent concentration (normality) up to the color change of phenolphthalein (pH 8.2).

Quicklime

Sodium hydroxide