Abstract: A highly sensitive and convenient test method, composition and device for the facile calorimetric determination of total dissolved solids in an aqueous sample having a low specific gravity is presented. The reagent composition comprises the mixture of a complex of a positively charged polyelectrolyte and a negatively charged indicator material, and an appropriate buffer system for maintaining the test system environment at an exact pH depending upon the indicator material selected. A preferable embodiment of this test system comprises the incorporation of the test composition into or with a solid state matrix material such as bibulous paper. The test system is particularly useful in the field testing of potable and recreational waters.

Abstract: A highly sensitive and convenient test method, composition and device for the facile calorimetric determination of total dissolved solids in an aqueous sample having a low specific gravity is presented. The reagent composition comprises the mixture of a complex of a positively charged polyelectrolyte and a negatively charged indicator material, and an appropriate buffer system for maintaining the test system environment at an exact pH depending upon the indicator material selected. A preferable embodiment of this test system comprises the incorporation of the test composition into or with a solid state matrix material such as bibulous paper. The test system is particularly useful in the field testing of potable and recreational waters.

Abstract: A dry reagent colorimetric test system for determining analytes in sample solutions containing interfering colored materials is presented comprising a reagent impregnated matrix containing a chromogenic material responsive to the analyte being detected and a masking dyestuff for obviating the interference caused by the colored materials thus allowing a proportional visual estimation of the response of the chromogenic material due to the amount of analyte in the sample solution.