Use of compounds which absorb and/or fluoresce in the IR region as markers for liquids

摘要

Use of compounds from the class of the phthalocyanines, naphthalocyanines, nickel dithiolene complexes, aminium compounds of aromatic amines, methine dyes or azulenesquaric acid dyes which have their absorption maximum in the range from 600 to 1,200 nm and/or a fluorescence maximum in the range from 620 to 1,200 nm, as markers for liquids, a process for detecting markers in liquids, and a detector suitable for this purpose.