title: Simple, quantitative method for low molecular weight dissolved organic matter extracted from natural waters based upon high performance counter-current chromatography.
abstract: A simple, high-performance counter-current chromatography method with sequential UV absorbance (254 nm) and evaporative light scattering detection (ELSD) was developed for the quantification of pre-extracted low molecular weight dissolved organic matter (DOM) extracted from natural waters. The method requires solid-phase extraction (SPE) extraction of only small volumes of water samples, here using poly(styrenedivinylbenzene)-based extraction cartridges (Varian PPL). The extracted and concentrated DOM was quantified using reversed-phase high-performance counter-current chromatography (HPCCC), with a water/methanol (5:5) mobile phase and hexane/ethyl acetate (3:7) stationary phase. The critical chromatographic parameters were optimised, applying a revolution speed of 1900 rpm and a flow-rate of 1 mL min(-1). Under these conditions, 50 μL of extracted DOM solution could be injected and quantified using calibration against a reference natural dissolved material (Suwannee River), based upon UV absorbance at 254 nm and ELSD detection. Both detection methods provided excellent linearity (R(2) > 0.995) for DOM across the concentration ranges of interest, with limits of detection of 4 μg ml(-1) and 7 μg ml(-1) for ELSD and UV absorbance, respectively. The method was validated for peak area precision (<5%), and accuracy and recovery based upon spiking seawater samples prior to extraction, together with DOM solutions post-extraction (>95% recovery). The developed method was applied to the determination of the concentration of DOM in seawater, based upon initial sample volumes as small as 20 mL.
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
authors: Alfonso
authors: A
authors: Rojas
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
authors: Sara
authors: S
authors: Sandron
authors: Central Science Laboratory (CSL), University of Tasmania, Private Bag 74, Hobart, Tasmania, 7001, Australia.
authors: Richard
authors: R
authors: Wilson
authors: Central Science Laboratory (CSL), University of Tasmania, Private Bag 74, Hobart, Tasmania, 7001, Australia.
authors: Noel W
authors: NW
authors: Davies
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
authors: Paul R
authors: PR
authors: Haddad
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
authors: Robert A
authors: RA
authors: Shellie
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
authors: Pavel N
authors: PN
authors: Nesterenko
authors: Australian Centre for Research on Separation Sciences (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia. Electronic address: Brett.Paull@utas.edu.au.
authors: Brett
authors: B
authors: Paull
keywords: Dissolved organic matter; Evaporative light scattering detection; High-performance counter-current chromatography; Quantification; Suwannee river natural organic matter