Test means for separate and total determination of heavy metals in aqueous media

The classification of the main indicators of the quality of water bodies is considered. The data on controlled chemical indicators are given (content of dissolved oxygen, suspended solids, phenols, petroleum products, etc.) A list of priority hydrochemical water pollutants and the sources of their pollution are presented. The expediency of determining both individual ions of heavy metals (HM) and their complex (integral) indicators is shown by the example of the sum of HMs. The authors summarized existing data on contemporary test methods used for detection and quantitative measurement of the most prominent HM pollutants of aqueous media, namely – Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Mn(II) and Al(III) ions. Concentration of such HM ions can be evaluated by various test means such as indicator papers, detector tubes and polymer plates etc. The main matrices of the test means are considered: cellulose papers, fabrics from artificial and natural fibers, silica gels, xerogels, polymeric materials, etc. The conditions for immobilization and modification of test means (carrying agent, reagent, surfactant, etc.) and principles of analyte determination using the developed test tools (visual and instrumental assessment of the intensity of staining of test forms, determination of the length of staining or bleaching of test tube zones, etc.), as well as some metrological characteristics (detection limit, range of determined contents, relative errors of definitions, etc.) are shown in this article. Detection limits of studied heavy metal ions in aqueous media that can be achieved with proposed test means are as follows: Fe(II) – (0.005-0.01) mg/l; Fe(III) – 0.1 mg/l; Co(II) – (0.02-0.4) mg/l; Ni(II) – (0.1-10) mg/l; Cu(II) – 0.05 mg/l; Mn(II) – 0.03 mg/l; Al(III) – 0.02 mg/l; total concentration of several HM ions – (0.0005-0.001) mg/l.