Speciation of Inositol Phosphates in Lake Sediments by Ion-Exchange Chromatography Coupled with Mass Spectrometry, Inductively Coupled Plasma Atomic Emission Spectroscopy, and ³¹P NMR Spectroscopy

Abstract

A method for the detection and speciation of inositol phosphates (InsP(n)) in sediment samples was tested, utilizing oxalate-oxalic acid extraction followed by determination by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) using electrospray ionization (ESI) in negative mode. The chromatographic separation was carried out using water and ammonium bicarbonate as mobile phase in gradient mode. Data acquisition under MS/MS was attained by multiple reaction monitoring. The technique provided a sensitive and selective detection of InsP(n) in sediment samples. Several forms of InsP(n) in the oxalate-oxalic acid extracted sediment were identified. InsP6 was the dominating form constituting 0.250 mg P/g DW (dry weight); InsP5 and InsP4 constituted 0.045 and 0.014 mg P/g DW, respectively. The detection limit of the LC-ESI-MS/MS method was 0.03 μM InsP(n), which is superior to the currently used method for the identification of InsP(n), (31)P nuclear magnetic resonance spectroscopy ((31)P NMR). Additionally sample handling time was significantly reduced.

Sediment phosphorus speciation and mobility under dynamic redox conditions

“…The NaOH-EDTA extraction resulted in a recovery of ∼ 27 % of TP, which is comparable to previous studies with carbonate-buffered soils and sediments (Hansen et al, 2004;Turner et al, 2003a). Alpha and beta glycerophosphates are commonly identified in monoester spectral regions and have been demonstrated to be products of diesters degraded during analysis (Doolette et al, 2009;Paraskova et al, 2015). As no glycerophosphates were identified in any of the analysed samples, recalculation of monoester / diester ratios was not performed.…”

Bone char effects on soil: sequential fractionations and XANES spectroscopy

“…Morshedizad et al: Bone char effects on soil: sequential fractionations and XANES spectroscopy rock phosphates (Powers, 1923;Lee et al, 1987;Fan et al, 2002) or meat and bone ashes (Schnug et al, 2003).…”

“…The precise characterization of various P species in the soil as a dynamic response to nonequilibrium conditions imposed by human activities, such as fertilization, can support a better understanding of reactivity, stability and particularly the plant accessibility of different P forms and provide a basis for best management practices. Several techniques, such as sequential fractionation (Dieter et al, 2010;Condron and Newman, 2011), nuclear magnetic resonance (NMR) spectroscopy (Liu et al, 2009;Vestergren et al, 2012;Ahlgren et al, 2013), Raman spectroscopy (Lanfranco, 2003;Vogel et al, 2013) and chromatography coupled to mass spectroscopy (De Brabandere et al, 2008;Paraskova et al, 2015), have been developed for P-speciation analysis in soil and sediments. Each one of these techniques can offer specific advantages and disadvantages depending on the phase and complexity of sample matrixes (Kruse et al, 2015).…”

Determination of d‐myo‐inositol phosphates in ‘activated’ raw almonds using anion‐exchange chromatography coupled with tandem mass spectrometry

“…InsP n forms were separated with an Agilent Infinity 1290 high‐performance LC (HPLC) system (Wilmington, DE, USA) using a weak anion‐exchange column (Hypersil GOLD AX, 100 mm × 2.1 mm, 3 µm) from Thermo Scientific (Pittsburg, PA) . The mobile phases for the chromatographic separation were 200 mmol L −1 aqueous ammonium carbonate, pH 9.0 (solvent A), and methanol in water, 5 : 95 v/v (solvent B).…”