Amperometric sensor for propanil

The metalloporphyrin 5,10,15,20-tetraphenylporphyrinatoiron(III) chloride shows catalytic activity for reduction of 3,4-dichloropropionanilide, the active ingredient of the herbicide Propanil. An amperometric sensor can therefore be constructed by coating the porphyrin catalyst as a thin layer on a glassy carbon electrode. The sensor provides reproducible responses at low concentrations with a lower detection limit (SN = 3) of 8 × 10−5 M. The useful lifetime of the sensor is about seven weeks.