Overview

This standard specifies a method for the preparation of acid extracts from pigments and extenders (hereinafter referred to as pigments for simplification of formulation) used for subsequent determination of metal soluble in hydrochloric acid. In contrast to the method according to DIN ISO 6713, the contents of "soluable" heavy metals are determined on "dry" pigments in this standard. The acid extracts are prepared with hydrochloric acid, c(HCl) = 0,07 mol/l. Metal contents which are defined as "soluable" metals in this extraction medium are determined in them. For pigments which cannot be wetted or incorporated into the specified volume of hydrochloric acid using the method specified in this standard, the method for preparation of acid extracts for determination of "soluable" shall be specifically agreed upon. The methods are not intended for pigments which are noticable soluable in hydrochloric acid, c(HCl) = 0,07 mol/l (for example zinc oxide pigments, carbonate extenders). The method according to 6.3 is one exception for extraction of "soluable" lead at higher lead contents. In this case a higher volume of extraction fluid with regard to the lead pigment is used and in some cases solubilities of more than 1 % are detected. It is not intended to determine the total percentage of a pigment soluable in hydrochloric acid c(HCl) = 0,07 mol/l in accordance with this standard. If it has been established in a suitable method of analysis that the total content of the metal concerned is lower than the relevant threshold value of "soluable" metal, the determination of the "soluable" metal is not necessary. This standard has been prepared by Working Committee NA 078-00-03 AA "Allgemeine Prüfverfahren für Farbmittel und Füllstoffe" ("General test methods for colorants and extenders") of the DIN Standards Committee Pigments and Extenders (NPF).

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Responsible national committee

NA 078-00-03 AA - General test methods for colorants and extenders