Spectrofluorimetric determination of chlorophylls and pheopigments using parallel factor analysis

Area of Science:

• Analytical Chemistry
• Environmental Science
• Spectroscopy

Background:

• Accurate quantification of chlorophylls and pheopigments is crucial for environmental monitoring.
• Traditional methods may struggle with complex sample matrices.
• Fluorescence excitation emission matrices (EEM) offer rich spectral information.

Purpose of the Study:

• To apply parallel factor analysis (PARAFAC) to EEM data for quantifying chlorophylls and pheopigments.
• To evaluate the predictive performance of PARAFAC against classical least squares (CLS) and reference methods.
• To investigate the "second-order advantage" in calibration models.

Main Methods:

• PARALLEL factor analysis (PARAFAC) applied to fluorescence EEM.
• Analysis of chlorophylls and pheopigments in acetone:water (9:1) solvent.
• Wavelength ranges: excitation 350-500 nm, emission 600-730 nm.
• Model validation using independent standards and Baltic Sea samples.

Main Results:

• PARAFAC model successfully decomposed mixtures into unique analyte components.
• PARAFAC showed comparable predictive ability to CLS for standards.
• PARAFAC demonstrated superior agreement with HPLC and visible spectroscopy for environmental samples.
• The "second-order advantage" confirmed that not all analytes need calibration inclusion.

Conclusions:

• PARAFAC is a robust method for analyzing complex pigment mixtures using EEM.
• PARAFAC offers significant advantages over CLS for real-world environmental sample analysis.
• This approach enhances the accuracy and reliability of pigment quantification in aquatic environments.