Semnificație și utilizare

4.1 Mercury is a toxic substance and is also harmful if present in caustic soda and caustic potassium used in some manufacturing processes. It therefore needs to be controlled as a possible pollutant. These test methods provide a way to measure mercury content of caustic soda and caustic potassium in liquids and solids.

ASTM E538-2017 Standard Test Method for Mercury in Caustic Soda (Sodium Hydroxide) and Caustic Potassium (Potassium hydroxide)

Etapa 1: Domeniul de aplicare

1.1 These test methods include routine determination of mercury and anhydrous caustic soda in solid, flake, ground and bead forms in caustic soda and caustic potassium solutions by flameless atomic absorption method.

1.2 The two test methods are described as follows: Test method A uses an alkaline reducing agent to analyze the sample directly, and the detection limit is 0.1ppb (ng/g). Test method A was developed using caustic soda and caustic potassium salts. Test method B, which requires pre-neutralization of the sample followed by permanganate oxidation followed by analysis with an acid reducing agent, has a lower detection limit of 0.01ppm (μg/ g). Test method B was developed using caustic soda.

1.3 Review the current Safety Data Sheet (SDS) for details on toxicity, first aid procedures and safety precautions.

1.4 Valorile exprimate în unități SI vor fi considerate valori standard. Nu sunt incluse alte unități de măsură în acest standard.

1.5 Acest standard nu este destinat să abordeze toate preocupările legate de siguranță (dacă există) asociat cu utilizarea acestuia. Este responsabilitatea utilizatorilor acestui standard de a stabili practici adecvate de securitate și sănătate și de a determina aplicabilitatea restricțiilor de reglementare înainte de utilizare.. Specific hazards are described in sections 7 și 18.

1.6 Acest standard internațional se bazează pe principiile de standardizare recunoscute la nivel internațional stabilite în “Decizia privind principiile pentru elaborarea standardelor internaționale, Orientări și recomandări” issued by the WTO Committee on Technical Barriers to Trade (TBT).