J. Saurina et al., 2ND-ORDER MULTIVARIATE CURVE RESOLUTION APPLIED TO THE FLOW-INJECTIONANALYSIS OF MIXTURES OF AMINO-ACIDS, Analytica chimica acta, 335(1-2), 1996, pp. 41-49
A flow injection system with diode-array multi-wavelength spectrophoto
metric detection was used to generate second order data. The system wa
s applied to monitoring the reaction between amino acids (lysine and p
roline) and 1,2-naphthoquinone-4-sulfonate (NQS) to give the correspon
ding derivatives. The sample injection produced a pH gradient which al
lowed the discrimination of the time profiles of the different amino a
cid derivatives. Each amino acid gave a FIA response which was arrange
d in a data matrix whose chemical rank was higher than one (more than
one spectrophotometrically active species was present in the reaction
system). The method was applied to the simultaneous determination of L
ys and Pro by second order multivariate curve resolution, obtaining a
global quantification error of 0.36%. The analysis of one of these ami
no acids in presence of the other as interference by using a pure stan
dard (without any information about the interference) was also studied
. In this case, errors in the quantification were of 2.75 and 3.0% for
Lys and Pro, respectively.