Horiba Aqualog – high speed combined fluorescence and absorbance analyzer

Aqualog

Optical characterizations of colored dissolved organic matter, including fluorescence Excitation-Emission Matrix analysis (EEM), offers a breadth of information about the source, bioavailability, diagenetic state and chemical composition of dissolved compounds in both soil and water. Within the Lund University Science departments, EEM is an established tool to study carbon dynamics in response to changes in vegetation, hydrology, cryology and other factors. Aqualog is a high-speed integrated absorption and fluorescence analyzer, ideal for sample-intense and long-term studies. The instrument performs the following on the same sample: 1) quantification of CDOM absorption spectrum; 2) scanning of fluorescence excitation-emission matrix (EEM) and; 3) automatic EEM data correction and processing. An EEM is a 3D representation of fluorescence intensity spectra obtained by excitation of CDOM molecules at different wavelengths. The matrix is first corrected by removal of Raman/Rayleigh scattering (noise cause by water), and then further adjusted for self-shading effects caused by the absorbance of the organic matter. Current EEM research predominantly utilizes the statistical fitting approach PARAFAC (parallel factor analysis) to identify and quantify peaks.

‘Aqualog-UV-800’ UV/NIR system from Horiba, interfaced with 24-position 10 ml vial autosampler ‘Alias-SP840.400’ from Spark Holland

Water quality monitoring

DOC characterization

Managed by Martin Berggren in consultation with the department’s general laboratory facility coordinator Marcin Jackowicz-Korczynski.