Abstract: A test substance detection method includes: a step A in which a sample containing a test substance and water, a compound having a structure in which a response site and a recognition site are connected via a spacer, and a surfactant are added; and a step B in which the recognition site and the test substance interact and a response at the response site arising from the interaction is detected. Further, also provided are: a purified water production method and an injection water production method both using the foregoing; a detection agent composition containing a compound represented by Formula (1) and a surfactant; and a detection apparatus, a purified water production facility, and an injection water production facility, all using the foregoing.

Abstract: A method of detecting an endotoxin of detecting an endotoxin from a test subject sample using a fluorescent substance having a structure in which a fluorescent site and a recognition site are connected by a spacer, wherein the recognition site recognizes a specific site of a molecular structure of an endotoxin.

Abstract: A process for removing electrolyte comprising forming a compartment for dealing with a liquid by juxtaposed arrangement of a first barrier across or through which a cation can be exchanged for hydrogen ion and a second barrier across or through which an anion can be exchanged for hydroxyl ion, forming a passage for acid solution outside the first barrier, forming a passage for alkaline solution outside the second barrier and inserting the liquid containing electrolyte into the compartment.