MilliporeSigma
  • LC-MS analysis of the plasma metabolome--a novel sample preparation strategy.

LC-MS analysis of the plasma metabolome--a novel sample preparation strategy.

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (2014-12-23)
Kasper Skov, Niels Hadrup, Jørn Smedsgaard, Henrik Frandsen
ABSTRACT

Blood plasma is a well-known body fluid often analyzed in studies on the effects of toxic compounds as physiological or chemical induced changes in the mammalian body are reflected in the plasma metabolome. Sample preparation prior to LC-MS based analysis of the plasma metabolome is a challenge as plasma contains compounds with very different properties. Besides, proteins, which usually are precipitated with organic solvent, phospholipids, are known to cause ion suppression in electrospray mass spectrometry. We have compared two different sample preparation techniques prior to LC-qTOF analysis of plasma samples: the first is protein precipitation; the second is protein precipitation followed by solid phase extraction with sub-fractionation into three sub-samples: a phospholipid, a lipid and a polar sub-fraction. Molecular feature extraction of the data files from LC-qTOF analysis of the samples revealed 1792 molecular features from the protein precipitation procedure. The protein precipitation followed by solid phase extraction procedure with three sub-samples gave a total of 4234 molecular features. This suggests that sub-sampling into polar, lipid and phospholipid fractions enables extraction of more metabolomic information as compared to protein precipitation alone. Chromatography showed good separation of the metabolites with little retention time drift (<1s) and a mass accuracy below 3 ppm was observed. The performance of the method was investigated using plasma samples from rats administered the environmental pollutant perfluorononanoic acid.

MATERIALS
Product Number
Brand
Product Description

Supelco
Linuron, PESTANAL®, analytical standard
Supelco
Bis(2-ethylhexyl) phthalate, PESTANAL®, analytical standard
Supelco
Bis(2-ethylhexyl) phthalate, Selectophore
Sigma-Aldrich
Isopropyl alcohol, ≥99.7%, FCC, FG
Supelco
Vinclozolin, PESTANAL®, analytical standard
Supelco
Bis(2-ethylhexyl) phthalate, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Supelco
Butylparaben, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Methanol solution, contains 0.10 % (v/v) formic acid, UHPLC, suitable for mass spectrometry (MS), ≥99.5%
Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Sigma-Aldrich
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 3 mm × 8 in.
Supelco
Residual Solvent - Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material
Plastic additive 01, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Formic acid, ACS reagent, ≥96%
Sigma-Aldrich
Isopropyl alcohol, meets USP testing specifications
Sigma-Aldrich
Formic acid, puriss., meets analytical specifications of DAC, FCC, 98.0-100%
Butyl parahydroxybenzoate, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Formic acid, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥98%
Sigma-Aldrich
Formic acid, reagent grade, ≥95%
USP
Butylparaben, United States Pharmacopeia (USP) Reference Standard
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Formic acid, ≥95%, FCC, FG
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Supelco
Acetonitrile, analytical standard
Sigma-Aldrich
Butyl 4-hydroxybenzoate, ≥99.0% (GC)
Sigma-Aldrich
2-Propanol, for molecular biology, BioReagent, ≥99.5%
Sigma-Aldrich
2-Propanol, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%, poly coated bottles
Sigma-Aldrich
2-Propanol, BioUltra, for molecular biology, ≥99.5% (GC)
Sigma-Aldrich
Formic acid solution, BioUltra, 1.0 M in H2O