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T-742.01.032 [2024-08] Acidic cleaning agents - acid concentration

Ready-made cleaning agents are composed of a large number of different components. The analysis of individual components is irrelevant in practice, and it is usually sufficient to determine the alkaline or acid-reacting components by summary analysis. The manufacturers of cleaning agents and disinfectants specify so-called titration factors in the operating instructions for the individualproducts, which are used to calculate the concentration in percent by volume or weight.

For products that are marketed as liquid concentrates, both factors - both for volume and weight percentages - are printed, as the products are both titrated and weighed by the consumer.

The titration factor (TF) is the reciprocal of the amount of standard solution (HCI or NaOH) in ml, which must be used to titrate a certain volume of exactly 1 % solution of a detergent.
TF × ml consumption = GG-% product in solution

In practice, there are various different templates of the cleaning solutions to be determined and normalities of the standard solutions in use: generally 10, 50 or 100 ml, which are diluted with 0.1 mol/l (0.1 N), 0.5 mol/l (0.5 N) or 1 mol/l (1.0 N) hydrochloric acid or sodium hydroxide solution against phenolphthalein or methyl orange. The resulting consumption of hydrochloric acid or sodium hydroxide solution in ml multiplied by the factor specified by the manufacturer gives the concentration of the cleaning solution in percent by volume or weight. For highly alkaline cleaning solutions, templates of 5 ml are also suggested. Some cleaning and disinfectant manufacturers also prescribe sulphuric acid or acetic acid instead of hydrochloric acid and recommend a certain normality, which makes further calculation unnecessary, so that the ml of acid used gives the concentration of the cleaning solution directly.

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Acidic cleaners are cleaning agents that contain acidic ingredients such as citric acid, acetic acid or phosphoric acid to dissolve and remove stubborn soiling. They are particularly effective at removing limescale, rust, mineral deposits and other acid-soluble residues.

acidic cleaners

cleaning agents

cleaning concentrates

working solutions

acid

titrimetric

Application/Purpose

Determination of the acid concentration of acidic cleaners.

Scope of Application

All acidic cleaning solutions.

Principle

The same principle applies here as for determining the concentration of alkaline cleaning solutions, except that titration solutions of corresponding normality are used.

Since the titration here is performed from the acid side (and not from the alkali side as in the determination of the p-value for alkaline detergents), the "minus p-value" (-p-value) is determined for acidic detergents.

H⁺ + NaOH → H₂O + Na⁺ very slightly pink against phenolphthalein