The present invention is directed to a fast, nondestructive measurement method for determining the contents of solid, liquid and/or suspended flowing organic compounds. The arrangement according to the invention comprises a sample vessel, a pump, and a measurement cell which form a unit together with a spectroscopic measurement head. The measurement cell is connected to the pump, which can be regulated to vary the flow rate, and to the sample vessel by a pipe, and the spectroscopic measurement head and the regulatable pump have electrical connections to a controlling and evaluating unit. Due to its compact construction, the solution which makes use of the principle of transflection is also particularly suited to mobile use, for example, to determine the components of liquid manure while the latter is being dispensed. In principle, the solution can be transferred to any applications with suspensions or pumpable, homogeneous and inhomogeneous materials.