Proposed Guidelines for Solid Phase Extraction of Suwannee River Dissolved Organic Matter

Abstract

This paper proposes improved guidelines for dissolved organic matter (DOM) isolation by solid phase extraction (SPE) with a styrene−divinylbenzene copolymer (PPL) sorbent, which has become an established method for the isolation of DOM from natural waters, because of its ease of application and appreciable carbon recovery. Suwannee River water was selected to systematically study the effects of critical SPE variables such as loading mass, concentration, flow rate, and up-scaling on the extraction selectivity of the PPL sorbent. High-field Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and proton nuclear magnetic resonance ( 1 H NMR) spectroscopy were performed to interpret the DOM chemical space of eluates, as well as permeates and wash liquids with molecular resolution. Up to 89% dissolved organic carbon (DOC) recovery was obtained with a DOC/PPL mass ratio of 1:800 at a DOC concentration of 20 mg/L. With the application of larger loading volumes, low proportions of highly oxygenated compounds were retained on the PPL sorbent. The effects of the flow rate on the extraction selectivity of the sorbent were marginal. Up-scaling had a limited effect on the extraction selectivity with the exception of increased self-esterification with a methanol solvent, resulting in methyl ester groups. Furthermore, the SPE/ PPL extract exhibited highly authentic characteristics in comparison with original water and reverse osmosis samples. These findings will be useful for reproducibly isolating DOM with representative molecular compositions from various sources and concentrations and minimizing potential inconsistencies among interlaboratory comparative studies.

Environmental Drivers of Dissolved Organic Matter Molecular Composition in the Delaware Estuary

“…The analytical window provided by the combination of PPL-SPE and FT-ICR-MS allowed us to examine a large, otherwise inaccessible portion of the DOM pool; in this study on average 67 ± 6% of the DOC was captured with our solid-phase extraction method. The PPL columns used here poorly recover very small and polar compounds (Raeke et al, 2016), but absorb a wide range of compounds of varying polarity and are thought to provide a major fraction of the natural DOM (Green et al, 2014;Li et al, 2016). The extraction efficiency did not significantly change along the salinity gradient of the estuary, indicating that our method captured a reproducible fraction of the estuarine DOM pool.…”

Solid-phase extraction-stepwise elution (SPE-SE) procedure for isolation of dissolved organic matter prior to ESI-FT-ICR-MS analysis

“…6) identified using the SPE-SE method, among which 873 C c H h O o compounds were identified only in SPE-SE, exceeding the total number of C c H h O o compounds in SPE-1E by 49%. SRFA had fewer C c H h O o compounds identified than DOM extracted from Klasmann peat, especially in the regions of high H/C or high O/C, such as saturated aliphatic, carbohydrate and tannic-like compounds, likely due to the complicated extraction process of SRFA [21]. However, the characters of molecules in different eluted fractions were similar to those of DOM p (shown in Fig.…”

“…In particular, it can be seen from the enlarged region of m/z 575.04e575.10 ( Fig. 1D) that an excellent m/z separation of F 1 from F 3 , such as C 21 Table 1). Comparing the C c H h O o molecular formulas obtained, there were 1978 molecular formulas observed in both SPE-1E and SPE-SE, and 1213 molecular formulas observed only in SPE-SE.…”

“…), and polymer-based sorbents (styreneedivinylbenzene copolymer, PPL) have been tested for their ability to isolate DOM from natural waters [18,19]. Among these, PPL sorbent has become a widely accepted medium for the isolation of DOM from natural waters due to its ease of application, high extraction efficiency and the highly representative character of the DOM in isolates [18,21]. In the SPE pretreatment procedures, DOM is first retained by a sorbent, and then eluted in one step using solvents such as methanol.…”

Differential effects of solid‐phase extraction resins on the measurement of dissolved lignin‐phenols and organic matter composition in natural waters

“…Keil and Neibauer () found that hydrophile‐lipophile balance (HLB) sorbents obtain equal or better recoveries of free monomeric lignin phenols compared to C‐18 sorbents and liquid‐liquid extraction in various aquatic environments. Another common SPE cartridge, the styrene divinyl benzene polymer (PPL) cartridge, was found to more efficiently extract marine DOM than C‐18 cartridges (Dittmar et al ) and is widely used for ultrahigh‐resolution mass spectrometry (Kellerman et al ; Roth et al ; Lechtenfeld et al ; Li et al ; Raeke et al ).…”