title: 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.
authors: Department of Chemistry-Biomedical Centre, Uppsala University , P.O. Box 599, S-751 24 Uppsala, Sweden.
authors: Julia V
authors: JV
authors: Paraskova
authors: Charlotte
authors: C
authors: Jørgensen
authors: Kasper
authors: K
authors: Reitzel
authors: Jean
authors: J
authors: Pettersson
authors: Emil
authors: E
authors: Rydin
authors: Per J R
authors: PJ
authors: Sjöberg
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D007295:Inositol Phosphates / Q000032:analysis* / Q000145:classification; D060106:Lakes / Q000737:chemistry; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D007295:Inositol Phosphates