Metadata

Description
Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC_5000A TOC analyzer. In advance to the analysis, samples were acidified with 3M HCl and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standard methods as a part of on-going estuarine water quality monitoring program htt://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. Fluorescence emission spectra were recorded at room temperature (20 degrees C) using a Perkin Elmer LS50B spectrofluorometer equipped with a 150-W Xenon arc lamp as the light source. Two fluorescence indices were obtained by single emission scan measurements at excitation wavelengths of 313 nm and 370 nm. For each scan, fluorescence intensity was measured at emission wavelengths ranging from 330 to 550 nm and from 385 to 550 nm, respectively with a 10nm bandpass for excitation and emission wavelengths. From the 313 nm scan the maximum intensity and maximum wavelength were determined (Donard, et al.,1989; De Souza Sierra et al., 1997). From the 370 nm scan a flurescence index (FI) was calculated (McKnight et al., 2001). Scan speed was set at 400 nm/min. Milli_Q water was used as a reference for all fluorescence analysis. Total maximum fluorescence intensity (Max I) and the fluorescence index, (FI) were determined at an excitation wavelength of 370 nm (Battin, 1998; McKnight et al., 2001). The maximum fluorescence emission wavelength (Max WL) was determined using an excitation wavelength of 313 nm (De Souza Sierra et al., 1997). In order to facilitate comparisons with other studies, the Max I was expressed in quinine sulfate units (QSU; 1 ng L-1 of quinine sulface monohydroxide). Synchronous excitation emission flurescence spectra of the water samples were obtained at constant offset value between excitation and emission wavelengths (delta lamda = lamda em - lamda ex). All spectra were recorded at an offset value of 30 nm with a slit width of 10 nm (Lu and Jaffe, 2001; Lu et al., 2003). The intensities of the four main peaks in the spectrum, namely at 275-286 nm (Peak I), 350nm (Peak II), 385 nm (Peak III) and 460 nm (Peak IV) were determined and the relative intensity of Peak I within this group was reported as %PeakI. All the fluorescence spectra were corrected for inner-filter effect according to McKnight et al. (2001) using UV-Vis absorption spectra. UV visible measurements of the water samples were carried out with 1 cm quartz UV visible cells at room temperature (20 degrees C), using a Shimadzu UV-visible double beam spectrophotometer. Milli-Q water was used as the reference. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical component was not corrected in this experiment, therefore, comparison of optical variables with other researcher's data was not conducted, instead limited the use to invesitgate our data set.

Citation
Battin, T J 1998. Dissolved organic matter and its optical properties in a blackwater tributary of the upper Orinoco river, Venezuela. Organic Geochemistry, 28: 561-569.

Instrumentation
Whatman 0.7um glass fiber filersShimadzu TOC-5000A Analyzer Perkin Elmer LS50B Spectrofluorometer Shimadzu UV-2101PC UV-VIS Spectrophotometer

Description
Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC_5000A TOC analyzer. In advance to the analysis, samples were acidified with 3M HCl and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standard methods as a part of on-going estuarine water quality monitoring program htt://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. Fluorescence emission spectra were recorded at room temperature (20 degrees C) using a Perkin Elmer LS50B spectrofluorometer equipped with a 150-W Xenon arc lamp as the light source. Two fluorescence indices were obtained by single emission scan measurements at excitation wavelengths of 313 nm and 370 nm. For each scan, fluorescence intensity was measured at emission wavelengths ranging from 330 to 550 nm and from 385 to 550 nm, respectively with a 10nm bandpass for excitation and emission wavelengths. From the 313 nm scan the maximum intensity and maximum wavelength were determined (Donard, et al.,1989; De Souza Sierra et al., 1997). From the 370 nm scan a flurescence index (FI) was calculated (McKnight et al., 2001). Scan speed was set at 400 nm/min. Milli_Q water was used as a reference for all fluorescence analysis. Total maximum fluorescence intensity (Max I) and the fluorescence index, (FI) were determined at an excitation wavelength of 370 nm (Battin, 1998; McKnight et al., 2001). The maximum fluorescence emission wavelength (Max WL) was determined using an excitation wavelength of 313 nm (De Souza Sierra et al., 1997). In order to facilitate comparisons with other studies, the Max I was expressed in quinine sulfate units (QSU; 1 ng L-1 of quinine sulface monohydroxide). Synchronous excitation emission flurescence spectra of the water samples were obtained at constant offset value between excitation and emission wavelengths (delta lamda = lamda em - lamda ex). All spectra were recorded at an offset value of 30 nm with a slit width of 10 nm (Lu and Jaffe, 2001; Lu et al., 2003). The intensities of the four main peaks in the spectrum, namely at 275-286 nm (Peak I), 350nm (Peak II), 385 nm (Peak III) and 460 nm (Peak IV) were determined and the relative intensity of Peak I within this group was reported as %PeakI. All the fluorescence spectra were corrected for inner-filter effect according to McKnight et al. (2001) using UV-Vis absorption spectra. UV visible measurements of the water samples were carried out with 1 cm quartz UV visible cells at room temperature (20 degrees C), using a Shimadzu UV-visible double beam spectrophotometer. Milli-Q water was used as the reference. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical component was not corrected in this experiment, therefore, comparison of optical variables with other researcher's data was not conducted, instead limited the use to invesitgate our data set.

Citation
De Souza Sierra, M M 1997. Spectral identification and behavior of dissolved organic fluorescence material during estuarine mixing processes. Marine Chemistry, 58: 51-58.

Instrumentation
Whatman 0.7um glass fiber filersShimadzu TOC-5000A Analyzer Perkin Elmer LS50B Spectrofluorometer Shimadzu UV-2101PC UV-VIS Spectrophotometer

Description
Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC_5000A TOC analyzer. In advance to the analysis, samples were acidified with 3M HCl and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standard methods as a part of on-going estuarine water quality monitoring program htt://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. Fluorescence emission spectra were recorded at room temperature (20 degrees C) using a Perkin Elmer LS50B spectrofluorometer equipped with a 150-W Xenon arc lamp as the light source. Two fluorescence indices were obtained by single emission scan measurements at excitation wavelengths of 313 nm and 370 nm. For each scan, fluorescence intensity was measured at emission wavelengths ranging from 330 to 550 nm and from 385 to 550 nm, respectively with a 10nm bandpass for excitation and emission wavelengths. From the 313 nm scan the maximum intensity and maximum wavelength were determined (Donard, et al.,1989; De Souza Sierra et al., 1997). From the 370 nm scan a flurescence index (FI) was calculated (McKnight et al., 2001). Scan speed was set at 400 nm/min. Milli_Q water was used as a reference for all fluorescence analysis. Total maximum fluorescence intensity (Max I) and the fluorescence index, (FI) were determined at an excitation wavelength of 370 nm (Battin, 1998; McKnight et al., 2001). The maximum fluorescence emission wavelength (Max WL) was determined using an excitation wavelength of 313 nm (De Souza Sierra et al., 1997). In order to facilitate comparisons with other studies, the Max I was expressed in quinine sulfate units (QSU; 1 ng L-1 of quinine sulface monohydroxide). Synchronous excitation emission flurescence spectra of the water samples were obtained at constant offset value between excitation and emission wavelengths (delta lamda = lamda em - lamda ex). All spectra were recorded at an offset value of 30 nm with a slit width of 10 nm (Lu and Jaffe, 2001; Lu et al., 2003). The intensities of the four main peaks in the spectrum, namely at 275-286 nm (Peak I), 350nm (Peak II), 385 nm (Peak III) and 460 nm (Peak IV) were determined and the relative intensity of Peak I within this group was reported as %PeakI. All the fluorescence spectra were corrected for inner-filter effect according to McKnight et al. (2001) using UV-Vis absorption spectra. UV visible measurements of the water samples were carried out with 1 cm quartz UV visible cells at room temperature (20 degrees C), using a Shimadzu UV-visible double beam spectrophotometer. Milli-Q water was used as the reference. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical component was not corrected in this experiment, therefore, comparison of optical variables with other researcher's data was not conducted, instead limited the use to invesitgate our data set.

Citation
Donard, O F 1989. High-sensitivity fluorescence spectroscopy of Mediterranean waters using a conventional or a pulsed laser excitation source. Marine Chemistry, 27: 117-136.

Instrumentation
Whatman 0.7um glass fiber filersShimadzu TOC-5000A Analyzer Perkin Elmer LS50B Spectrofluorometer Shimadzu UV-2101PC UV-VIS Spectrophotometer

Description
Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC_5000A TOC analyzer. In advance to the analysis, samples were acidified with 3M HCl and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standard methods as a part of on-going estuarine water quality monitoring program htt://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. Fluorescence emission spectra were recorded at room temperature (20 degrees C) using a Perkin Elmer LS50B spectrofluorometer equipped with a 150-W Xenon arc lamp as the light source. Two fluorescence indices were obtained by single emission scan measurements at excitation wavelengths of 313 nm and 370 nm. For each scan, fluorescence intensity was measured at emission wavelengths ranging from 330 to 550 nm and from 385 to 550 nm, respectively with a 10nm bandpass for excitation and emission wavelengths. From the 313 nm scan the maximum intensity and maximum wavelength were determined (Donard, et al.,1989; De Souza Sierra et al., 1997). From the 370 nm scan a flurescence index (FI) was calculated (McKnight et al., 2001). Scan speed was set at 400 nm/min. Milli_Q water was used as a reference for all fluorescence analysis. Total maximum fluorescence intensity (Max I) and the fluorescence index, (FI) were determined at an excitation wavelength of 370 nm (Battin, 1998; McKnight et al., 2001). The maximum fluorescence emission wavelength (Max WL) was determined using an excitation wavelength of 313 nm (De Souza Sierra et al., 1997). In order to facilitate comparisons with other studies, the Max I was expressed in quinine sulfate units (QSU; 1 ng L-1 of quinine sulface monohydroxide). Synchronous excitation emission flurescence spectra of the water samples were obtained at constant offset value between excitation and emission wavelengths (delta lamda = lamda em - lamda ex). All spectra were recorded at an offset value of 30 nm with a slit width of 10 nm (Lu and Jaffe, 2001; Lu et al., 2003). The intensities of the four main peaks in the spectrum, namely at 275-286 nm (Peak I), 350nm (Peak II), 385 nm (Peak III) and 460 nm (Peak IV) were determined and the relative intensity of Peak I within this group was reported as %PeakI. All the fluorescence spectra were corrected for inner-filter effect according to McKnight et al. (2001) using UV-Vis absorption spectra. UV visible measurements of the water samples were carried out with 1 cm quartz UV visible cells at room temperature (20 degrees C), using a Shimadzu UV-visible double beam spectrophotometer. Milli-Q water was used as the reference. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical component was not corrected in this experiment, therefore, comparison of optical variables with other researcher's data was not conducted, instead limited the use to invesitgate our data set.

Citation
Lu, X Q 2003. Molecular characterization of dissolved organic matter in freshwater wetlands of the Florida Everglades. Water Research, 37: 2599-2606.

Instrumentation
Whatman 0.7um glass fiber filersShimadzu TOC-5000A Analyzer Perkin Elmer LS50B Spectrofluorometer Shimadzu UV-2101PC UV-VIS Spectrophotometer

Description
Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC_5000A TOC analyzer. In advance to the analysis, samples were acidified with 3M HCl and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standard methods as a part of on-going estuarine water quality monitoring program htt://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. Fluorescence emission spectra were recorded at room temperature (20 degrees C) using a Perkin Elmer LS50B spectrofluorometer equipped with a 150-W Xenon arc lamp as the light source. Two fluorescence indices were obtained by single emission scan measurements at excitation wavelengths of 313 nm and 370 nm. For each scan, fluorescence intensity was measured at emission wavelengths ranging from 330 to 550 nm and from 385 to 550 nm, respectively with a 10nm bandpass for excitation and emission wavelengths. From the 313 nm scan the maximum intensity and maximum wavelength were determined (Donard, et al.,1989; De Souza Sierra et al., 1997). From the 370 nm scan a flurescence index (FI) was calculated (McKnight et al., 2001). Scan speed was set at 400 nm/min. Milli_Q water was used as a reference for all fluorescence analysis. Total maximum fluorescence intensity (Max I) and the fluorescence index, (FI) were determined at an excitation wavelength of 370 nm (Battin, 1998; McKnight et al., 2001). The maximum fluorescence emission wavelength (Max WL) was determined using an excitation wavelength of 313 nm (De Souza Sierra et al., 1997). In order to facilitate comparisons with other studies, the Max I was expressed in quinine sulfate units (QSU; 1 ng L-1 of quinine sulface monohydroxide). Synchronous excitation emission flurescence spectra of the water samples were obtained at constant offset value between excitation and emission wavelengths (delta lamda = lamda em - lamda ex). All spectra were recorded at an offset value of 30 nm with a slit width of 10 nm (Lu and Jaffe, 2001; Lu et al., 2003). The intensities of the four main peaks in the spectrum, namely at 275-286 nm (Peak I), 350nm (Peak II), 385 nm (Peak III) and 460 nm (Peak IV) were determined and the relative intensity of Peak I within this group was reported as %PeakI. All the fluorescence spectra were corrected for inner-filter effect according to McKnight et al. (2001) using UV-Vis absorption spectra. UV visible measurements of the water samples were carried out with 1 cm quartz UV visible cells at room temperature (20 degrees C), using a Shimadzu UV-visible double beam spectrophotometer. Milli-Q water was used as the reference. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical component was not corrected in this experiment, therefore, comparison of optical variables with other researcher's data was not conducted, instead limited the use to invesitgate our data set.

Citation
McKnight, Donard M 2001. Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. Limnology and Oceanography, 46: 38-48.

Instrumentation
Whatman 0.7um glass fiber filersShimadzu TOC-5000A Analyzer Perkin Elmer LS50B Spectrofluorometer Shimadzu UV-2101PC UV-VIS Spectrophotometer