Multichannel pipette scanning colorimeter for analyzing the content of hazardous chemicals in water

Abstract

A prototype of a multichannel pipette scanning colorimeter for determining the content of certain hazardous chemicals in water selected from the list presented in the Russian Federation Hygienic Regulations GN 2.1.5.1315-03 was designed and manufactured. The colorimeter consists of test-slides, a matrix electronic multichannel pipette, color scales, and slide-scanner. The test slide has 16 reagent test strips intended for detection of 16 different contaminants in water:NH 4 + , Al(III), Fe(III), Cu(II), As(III), petrochemicals, NO 2 − ,NO 3 − , SO 4 2− , S2−, Cl−, phenols, Zn(II), anionic surfactants, Pb(II), etc. Color scales were obtained by measuring the L*a*b* color space coordinates of test strips using a Plustek OpticFilm 7600i Ai slide scanner, a specially developed software, and Adobe Photoshop v.12.0.4. Digitizing the color of the test strip was carried out after the chromogenic chemical reaction between the test reagent and the pollutant in aqueous solutions of graded concentrations. The multichannel pipette scanning colorimeter passed preliminary tests, during which the concentrations of pollutants in water within ranges close to the maximum permissible concentrations specified by the RF hygienic and fishery water regulations. The errors in concentration measurements using the colorimeter designed meet the requirements of the State Standard GOST 27384-2002 (“Water: Rated Errors of Measurements of Compositions and Properties”).