FLOW-INJECTION SPECTROPHOTOMETRIC DETERMINATION OF AMINO-ACIDS BASED ON AN IMMOBILIZED COPPER(II) ZINCON SYSTEM

The flow-injection spectrophotometric determination of different amino acids was carried out by reaction with copper(II) ions entrapped in a polymeric material and filling a packed-bed reactor; the released cop per(II), complexed with the amino acid, reacted with zincon in a basic medium producing a blue colour that was monitored at 600 nm. The meth od was applied to determine the contents of different amino acids in p harmaceutical formulations. The calibration graph for glycine was line ar over the range 0.5-20 mug ml-1 with a relative standard deviation o f 0.8% (n = 6) at 10 mug ml-1 and a sample throughput of 108 h-1.