02020nam a2200217 a 450000100080000000500110000800800410001910000260006024501390008626000990022530000120032452013410033665000160167765300160169365300100170965300180171970000190173770000170175670000140177370000150178710475872023-06-13       2006    bl uuuu     u00u1 u    #d1 aNOGUEIRA, A. R. de A.  aFlow injection potentiometric system for ATP determination in pharmaceutical samples using experimental design.h[electronic resource]  aIn: INTERNATIONAL CONFERENCE FLOW ANALYSIS, 10., 2006, Porto. Proceedings... Porto: IAFAc2006  ap. 183.  aTo identify thenítrogen transportation formsand attaín lhe control mechanísm, lhe amount of free amino acids in different parts of lhe plant has to be determined. An automatic, fast and relíable procedure multícomutated flow system [1] has been developed for spectrophotometríc analysís of totalamíno acíds in plant material. The method is suitable for routine analysís for a largenumber of samples of plant material. The flow manifold was designed with computer- controlled three-way solenoíd valves forindependent handlíng of sample and reagent solutions and a data acquisition system from a spectrophotometer, employed for sígnal measurements. The software for system control was performed bya program with use of a LabView platform (Nationallntrumentsl [2]. The detection reaction was based on the complexation of amino functíonal groups ofamino acids by nínhydrin. It reacts with free a-amino groups, producing the colored ninhydrin chromophore called Ruhemann's purple (RP) IAmax = 570 nm; (= 22000) [3]. The proposed detection system shows a linear range concentration upto 2.0 x 10-3 mal L-1 wíth coefficient of variation of 1.1% (n = 10). Detection limíts wereestimated as 2.8 x 10-3 mal L-1 at 99.7% confidence level for total amino acids, and a mean sampling rate of 30 determínQtions per hour was achieved.  aamino acids  aFlow system  aPlant  aSpectrometric1 aMOTA, A. V. C.1 aLEMOS, S. G.1 aPARRA, A.1 aALONSO, J.