Review of analytical methods for lead determination in paints and varnishes

Abstract

Introduction. The draft Technical Regulation of the Eurasian Economic Union “On the Safety of Paint and Varnish Materials” establishes the lead content in paint and varnish materials for interior and exterior surfaces of residential and (or) public premises, furniture products, playgrounds, products for children and adolescents, attractions, products in contact with food, and used for water treatment equipment at a level not exceeding 0,009% of the total weight of non-volatile chemicals with a transition period of 60 months. Current GOST R 50279.10-92 (ISO 6503-84) (GOST R 50279.10-92 (ISO 6503-84). Paints and varnishes. Methods for determination of metal content. Determination of total lead content. Flame atomic absorption spectrometry method) and GOST R 50279.3-92 (ISO 3856/1-84) (GOST R 50279.3-92 (ISO 3856/1-84). Paints and varnishes. Methods for determination of metal content. Determination of “dissolved” lead content. Flame atomic absorption spectrometry and dithizone spectrophotometric method) with detection limits of lead at 0,01% (by weight) do not provide the required sensitivity, and therefore it becomes necessary to develop and approve in accordance with the established procedure an analytical method for lead determination in paint and varnish materials at the level of 0,0045% of the total weight of non-volatile chemicals (1/2 of the established standard). Materials and methods. Documents, guidelines and webinars of the Eurasian Economic Union, the World Health Organization, the United Nations Environment Program, the American Society for Testing and Materials (ASTM International), the International Organization for Standardization (ISO), the US Environmental Protection Agency (EPA), manufacturers of analytical equipment (26 sources in total) were used in the preparation of the review. Results and discussions. The review presents the most common methods for lead determination in paints and varnishes, indicating their characteristics, advantages and limitations: flame atomic absorption spectrometry; atomic absorption spectrometry with electrothermal atomization; atomic emission spectrometry with inductively coupled plasma; X-ray fluorescence spectrometry. Conclusion. A systematic analysis of the methods for lead determination in paints and varnishes existing in domestic and foreign practice, taking into account the lower detection limit, as well as the costs of consumables and equipment maintenance, allows to identify three methods that are of interest in terms of developing guidelines: atomic absorption spectrometry with electrothermal atomization; atomic emission spectrometry with inductively coupled plasma; high-resolution X-ray fluorescence spectrometry.