Comparison between a new application of multivariate regression and current spectroscopy methods for the determination of chlorophylls and their corresponding pheopigments
L. Moberg et al., Comparison between a new application of multivariate regression and current spectroscopy methods for the determination of chlorophylls and their corresponding pheopigments, ANALYT CHIM, 411(1-2), 2000, pp. 137-143
A multivariate calibration model, partial least squares regression for seve
ral independent variables (PLS2), has been developed for the simultaneous d
etermination of chlorophyll a, b and c and the corresponding pheophytin a a
nd b and pheoporphyrin c. Mixtures with these six components were prepared
at four concentration levels with respect to each analyte, in acetone:water
. The concentration for chlorophyll ct varied from 1 to 7 mg l(-1). Absorba
nce spectra in the visible range, 350-770 nm, were registered. The predicti
ve ability, reported as the root mean square error of prediction (RMSEP), w
as found to be 0.167 mg l(-1) for chlorophyll a. Similar results were found
for the other analytes. The spectral data were also evaluated with the abs
orption spectroscopy procedures recommended in Standard Methods for the Exa
mination of Water and Wastewater. For chlorophyll a, the proposed multivari
ate method improved the predictive ability by a factor 2.4. Data is availab
le at: http://www.anchem.su.se (C) 2000 Elsevier Science B.V. All rights re
served.