A comparison of orthogonal signal correction and net analyte preprocessing methods. Theoretical and experimental study

GOICOECHEA, HÉCTOR C; AC OLIVIERI,

CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS

Elsevier

Año: 2001 vol. 56 p. 73 - 81

0169-7439

A comparison is presented between orthogonal signal correctionŽOSC.and net analyte signalŽNAS.calculations. It was shown that the latter can be used as a preprocessing method comparable to the former, before the application of partial least-squaresŽPLS.to the filtered data. When the number of factors used in the net analyte preprocessingŽNAP.procedure increases, the subsequent application of PLS requires progressively less factors, a behavior comparable to OSC. If enough factors are extracted by either NAP or OSC methods, the remaining calibration problem is amenable to a classical least-squares solution, giving rise to two multivariate calibration methods named NAPrCLS and OSCrCLS. All methods are illustrated from cross-validation and external validation results for two experimental examples: Ž1. the determination of the antibiotic tetracycline in human serum, and Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.ŽOSC.and net analyte signalŽNAS.calculations. It was shown that the latter can be used as a preprocessing method comparable to the former, before the application of partial least-squaresŽPLS.to the filtered data. When the number of factors used in the net analyte preprocessingŽNAP.procedure increases, the subsequent application of PLS requires progressively less factors, a behavior comparable to OSC. If enough factors are extracted by either NAP or OSC methods, the remaining calibration problem is amenable to a classical least-squares solution, giving rise to two multivariate calibration methods named NAPrCLS and OSCrCLS. All methods are illustrated from cross-validation and external validation results for two experimental examples: Ž1. the determination of the antibiotic tetracycline in human serum, and Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.ŽPLS.to the filtered data. When the number of factors used in the net analyte preprocessingŽNAP.procedure increases, the subsequent application of PLS requires progressively less factors, a behavior comparable to OSC. If enough factors are extracted by either NAP or OSC methods, the remaining calibration problem is amenable to a classical least-squares solution, giving rise to two multivariate calibration methods named NAPrCLS and OSCrCLS. All methods are illustrated from cross-validation and external validation results for two experimental examples: Ž1. the determination of the antibiotic tetracycline in human serum, and Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.rCLS and OSCrCLS. All methods are illustrated from cross-validation and external validation results for two experimental examples: Ž1. the determination of the antibiotic tetracycline in human serum, and Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.Ž1. the determination of the antibiotic tetracycline in human serum, and Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.Ž2. the quantitation of the nasal decongestant naphazoline in multicomponent pharmaceutical solutions.