title: Quantifying F2-isoprostanes in umbilical cord blood of newborn by gas chromatography-mass spectrometry.
abstract: We attempted to improve the extraction procedures to determine the F(2)-isoprostanes in plasma of umbilical cord arterial and venous blood by gas chromatography mass spectrometry. Plasma samples were deproteinized and hydrolyzed; free and esterified F(2)-isoprostanes were extracted by solid-phase extraction columns with citric acid/methanol/cyclohexane and ammonia solution/methanol and then derivatized by PFBBr and BSTFA. Concentrations of total plasma F(2)-isoprostanes eluted at the retention time of an internal standard of 8-iso-prostaglandin F(2alpha)-D(4) were quantified. The absolute recovery was 83+/-1.9% (95% confidence). Intraassay precision and interassay precision were lower than 1.0%. Analytical accuracy was 99.0+/-0.4% (95% confidence). Linearity, r(2), over the concentration range of 10 to 5000 pg/ml of spiked 8-iso-prostaglandin F(2alpha) in plasma was 0.9985. The method detection limit was 21 pg/ml (99% confidence) and the limit of quantitation was approximately 4 pg/ml. Analysis of 200 neonatal cord blood samples revealed few overlapping peaks causing interference in the elution of the F(2)-isoprostanes. With the use of an autosampler and one technician, 48 samples can be completed within 24h with 6h of actual hands-on work. This method could be potentially employed for routine analysis of plasma F(2)-isoprostanes in clinical laboratories.
authors.affiliation: Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China. msrogers@cuhk.edu.hk
authors.forename: Kai On
authors.initials: KO
authors.lastname: Chu
authors.forename: Chi Chiu
authors.initials: CC
authors.lastname: Wang
authors.forename: Michael Scott
authors.initials: MS
authors.lastname: Rogers
authors.forename: Chi Pui
authors.initials: CP
authors.lastname: Pang
mesh_terms: D028441:F2-Isoprostanes / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D013997:Time Factors
chemical_list: D028441:F2-Isoprostanes