Abstract: A chemical sensor and method for in-line chemical analysis including a body having a central cavity. The body also has a pair of openings through it to the cavity. A porous plug, such as a ceramic frit, is sealed into each of these openings so that there is a space between the plugs in the cavity. A vent passageway through the body to the cavity is also provided. A pressurized sample is flowed through one porous plug into the cavity while a pressurized reagent is flowed through the other porous plug into the cavity. A component of interest of the sample reacts with a reactive component of the reagent in the cavity to produce a reaction product. The reaction product is analyzed in the cavity by, for example, absorption spectroscopy. As fresh sample and reagent flow into the cavity, the reaction products flow out of the cavity by way of the vent passageway.

Abstract: A chemical analysis method for the determination of a first organic acid in the presence of a second organic acid both of which are in a solution to be analyzed, the pK.sub.a of the first acid being at least 2 pK.sub.a units larger than the pK.sub.a of the second acid. The method includes three steps. The first step if to form a pH adjusted solution to be analyzed by adjusting the pH of the solution to be analyzed to be between the pK.sub.a of the first acid and the pK.sub.a of the second acid so that the first acid is predominately in its unionized form and so that the second acid is predominately in its ionized form.