No abstract

Fluorescence excitation-emission matrices (FEEMs) and parallel factor analysis (PARAFAC) techniques are able to evaluate the chemical characteristics of overlapping fluorophores and bands in FEEM. In this study, FEEM-PARAFAC was applied to distinguish the differences among metabolic organic components from Pseudomonas fluorescents P17 and Spirillum NOX strains in an assimilable organic carbon bioassay with acetate as the primary substrate. Three metabolic components from P17 and NOX strains were selected and grown in different acetate concentrations based on the simultaneous consideration of verification of variance, core consistency, residuals, and split-half experiments. The results from control tests show that metabolic humic-like substances in the NOX strain were more prevalent than they were in the P17 strain. Metabolic humic-like substances from the P17 strain increased with escalating acetate concentrations, while a descending trend occurred in experiments with the NOX strain, indicating that the composition of metabolic organic matter containing nitrogen and humic-like substances varied according to the acetate concentrations.

In recent years, the 3D fluorescence excitation emission spectrum has been widely applied into the analysis of the properties of soluble organic matter in water bodies, but there is very little research on the fluorescence properties of protein residues in water quality detection by Fluorescence Excitation Emission Matrix (FEEM), and synchronous fluorescence excitation emission spectra (SFS). The characteristics of luminescent of amino acids, including tryptophan, tyrosine and phenylalanine, where tryptophan and tyrosine fluorescence are relatively strongest, and the effects of tyrosine on the fluorescence properties of tryptophan are seldom discussed in different mixing ratios for both amino acids. The fluorescent peak positions and intensities of the three amino acids are related to the angle size of conjugate plane, N hybrids and hydroxyls on benzene rings. When the ratio of tyrosine to tryptophan content is less than 150:100, tryptophan will quench the fluorescent peak of the tyrosine. Constant tryptophan content, tyrosine at excitation wavelength of 228 nm, its concentration changes with the corresponding fluorescence intensity has a good linear relationship; however, at 276-278 nm of tyrosine, the varied concentrations and fluorescence intensities are opposite.

In this study, Excitation Emission Fluorescent matrix (EEFM) integrated with Parallel factor analysis (PARAFAC) was applied to investigate the variation of organic property in DonggangRiver located in Southern Taiwan between Oct. 2010 and Oct. 2015