1. DETERMINATION OF PLASMA PHENYLALANINE CONCENTRATION BY TWO DIMENSIONALTHIN LAYER CHROMATOGRAPHY AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHY IN RELATION WITH DIAGNOSIS OF PHENYLKETONURIA. Authors: CIPRIAN-VALENTIN MIHALI, CĂLIN FLAVIU LADAȘIU CIOLACU, LUCIAN FRENȚESCU, CONSTANTIN-MARIAN PETRESCU, IULIA MÂNDRUȚIU, DORIN BECHET, TIBERIU NISTOR, AUREL ARDELEAN, GHEORGHE BENGA.