Method and device for determining a sample stream concentration value of an analyte in a sample stream

A method for determining a concentration of an analyte in a sample stream containing the analyte and a solvent, wherein the sample stream has a concentration of the analyte that subceeds a saturation concentration of the analyte in the solvent by no more than 4% of the saturation concentration, the method comprising:

• preparing a measured stream by diluting the sample stream with a solvent stream, wherein the measured stream thereby has a concentration of the analyte that subceeds the saturation concentration of the analyte in the solvent by not less than 8% of the saturation concentration;
• determining a measured stream concentration value of the analyte in the measured stream by determining a density of the measured stream that depends on a concentration of the analyte in the measured stream, wherein the density of the measured stream is determined via a vibronic sensor based on at least one oscillation frequency of the vibronic sensor;
• and
• determining the concentration of the analyte in the sample stream as a function of the measured stream concentration value and a dilution ratio of the sample stream and the measured stream.