NOVELTY - An optical-sensory and/or chemical analysis method for determination of constituent(s) (I) in water, by chemical and/or fermentation reaction, involves determining (I) in a predetermined volume of water at a predetermined location within a body of water using a chemically reactive pigment (A) applied to a carrier, where (A) dissolves in the specific volume of water due to a chemical and/or fermentation reaction or is converted into a different pigment.    USE - The water analysis method is specifically used for analysis of bodies of water, especially flowing water, waste water channels, water reservoirs, natural or artificial lakes, seas, oceans or groundwater; and the gas analysis method is specifically used for analyzing the atmosphere in well shafts, mine workings, tunnels, shafts, waste water plants, refuse and composting plants and cave systems (all claimed). The analytes (I) are especially hydrogen sulfide, ferrous ion, total biologically utilizable reductants and oxygen.    ADVANTAGE - A simple and direct method is provided for determining the material concentrations at specific locations in bodies of water. Typically ferrous carbonate (as (A)) turns from white to light gray in presence of low concentrations of hydrogen sulfide (as (I)) or to black in presence of high concentrations of hydrogen sulfide.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an analogous method for determination of component(s) (I) in a gas.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram view of apparatus for the process.    Inner container (1)    Outlet flow opening (2)    Inner container base, with inflow openings (3)    Outer container (4)    Outer container base, with inflow openings (5)    Loop-form holding device (6)    Handle on the outer container (7)    Pull rope for outer container (8)    Pull rope for pressure piston (9)    Pressure piston (10)    Suspended carrier particle with deposit of sorption pigment (A), in loose or fixed bed form (11)    Opening for operating pull rope (12)    Cylindrical intermediate space around pressure piston (13)    Cylindrical intermediate space around inner container (14)    Gap (15)    Body of water (16)