Paints and varnishes. Determination of "soluble" metal content. Part 5: Determination of hexavalent chromium content of the pigment and extender portion of the paint. Diphenylcarbazide spectrophotometric method
This part of ISO 3856 specifies a diphenylcarbazide spectrophotometric method for the determination of the "soluble" hexavalent chromium content of the hydrochloric acid extract of the pigment and extender portion of the product, prepared according to clause 7 of ISO 6713 or other suitable Interna-tional Standards.1)
The method is applicable to paints having "soluble" metal contents in the range of about 0,05 to 5 % (m/m).
Other methods can be used by agreement between the interested parties, provided that the methods are specific for hexavalent chromium but, in case of dispute, this spectrophotometric method should be used.