Abstract: An apparatus and method for automatically analyzing up to 150 samples per hour with high precision. Air segmentation and its concomitant limitations and drawbacks are eliminated by use of a novel stream sampling valve which transfers a predetermined volume of sample only from a sample flow system to a reaction flow system.

Abstract: A method and apparatus for the detection of primary and secondary amino acids in a known sequence in a liquid sample stream. The amino acids are rendered detectable by reaction with a fluorometric reagent such as fluorescamine. A conversion reagent, e.g., N-chlorosuccinimide, is added to the sample streams only when secondary amine is present. Baseline shift in the fluorometric detection is avoided by adding an inert liquid diluent stream to the sample stream at a predetermined flow rate at all times except when the conversion reagent is added. By maintaining the diluent and N-chlorosuccinimide streams under constant pressure and synchronously switching between streams to coincide with the presence of a primary or secondary amino acid, liquid flow through the fluorometer is maintained at a substantially constant rate throughout the run.