Abstract: A fluorimetric flow injection method is described for the quantitation of cyanide ions in aqueous media. The method is based on the isoindole fluorogenic adduct formed when o-phthalaldehyde reacts with taurine in the presence of CN-ions. Under optimized flow injection conditions (loop size, 130 µl; flow rate, 0.75 mL min-1; delay coil length, 0.4 m) linear calibration curves in the range 10^-5 to 10^-7 M CN- are obtained with detection limits of 1.8 x 10^-7 M. Using naphthalene dialdehyde instead of o-phthalaldehyde the detection limit is lowered to 5.8 x 10^-8 M. Recovery yields vary between 97-102%. Incorporation of a linamarase bioreactor into the flow injection manifold gives a rapid and sensitive method for the quantitation of the cyanogenic glucoside, linamarin, in cassava. Linamarin concentrations as low as 3.2 x 10^-6 M call be detected. The immobilized linamarase shows excellent storage stability at 4°C retaining about 72% of its activity after 109 days. 19 References