Coupling asymmetric flow-field flow fractionation and fluorescence parallel factor analysis reveals stratification of dissolved organic matter in a drinking water reservoir

Suitability of Organic Matter Surrogates to Predict Trihalomethane Formation in Drinking Water Sources

“…PARAFAC component EEMs from Model 1 (consisting of 44 EEMs from this study) and Model 2 (consisting of 416 EEMs, including 372 EEMs from previous studies) (Pifer et al, 2011;Pifer and Fairey, 2012) are shown in Supplementary Figure S4 and the locations of their excitation and emission peak maxima are presented in Table 2. In terms of identifying these PARAFAC components, fluorophore groups in DOM samples of unknown composition have traditionally been categorized as humic like, fulvic like, or protein like based on comparisons of their excitation and emission maxima to Stedmon and Markager (2005).…”

“…Raw water pH, alkalinity, and turbidity were measured as described by Pifer et al (2011). Following sample filtration with 0.7-lm GFFs as described in the Glassware and Reagents section, conductivity was measured using a Malvern Zetasizer Nano ZS90.…”

“…However, the emission maxima (562 nm) is higher than those of any PARAFAC component identified and adjacent to the second-order Raman scattering region. This region was excised and interpolated using a Delauney interpolation algorithm within the EEM Cleanscan protocol (Zepp et al, 2004;Pifer et al, 2011). Similarly, I 266/482 is near to the excitation and emission maxima of humic acid-like components (C1.2, C2.2, and C2.5), but near the second-order Rayleigh scattering region.…”

“…A secondary objective of this research was to evaluate the impact of PARAFAC model size (e.g., the number of EEMs used to fit the model) on the quality of F MAX values as TTHMFP precursor surrogate parameters. Two PARAFAC models were fit and comparedone was made using only the 44 EEMs measured in this study, and the other created by combining these 44 EEMs with 378 EEMs collected as part of two previously published reports (Pifer et al, 2011;Pifer and Fairey, 2012).…”

Particulate Phases Possibly Conveyed from Nuclear Waste Repositories by Groundwater

“…The version of the manufactured separation system for which the channel conveying the carrier liquid had an asymmetric shape (As-Fl-FFF) proved to be the most efficient, as it enabled nanoparticles ranging form 1 nm to 100 μm to be separated. As a general rule, an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is used as on-line detector, which allows reaching low detection limits, high sensitivity, large dynamic range and ability to simultaneously measure a large number of elements (Table 1) A large number of recent works contributing to the development of the FFF techniques significantly widened their applicability range in particle size analysis (Ahn et al, 2010;Baalousha et al, 2006;Dubascoux et al, 2008;Gascoyne, 2009;Isaacson & Bouchard, 2010;Otte et al, 2009;Pifer et al, 2011).…”