| Author: | Yu, Wai-yuen |
| Title: | Quantification of urinary F₂-isoprostanes as a biomarker of oxidant stress using liquid chromatography-triple quadrupole mass spectrometry : method evaluation and application in study of biological variation in aging |
| Degree: | M.Sc. |
| Year: | 2010 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Oxidative stress |
| Department: | School of Nursing |
| Pages: | x, 94 p. : ill. (some col.) ; 30 cm. |
| Language: | English |
| Abstract: | Quantification of 8-isoprostaglandin-F₂α (8-iPGF₂α) in urine has been suggested to be a reliable and non-invasive method to monitor lipid peroxidation and oxidative stress. Here, the development and technical evaluation of a liquid chromatography (LC) with negative electrospray ionization (ESI) coupled to tandem mass spectrometry (MS/MS) method for analysis urinary 8-iPGF₂α are described. Urine 8-iPGF₂α on samples from 91 apparently healthy subjects aged 20-65 years and 100 frail elderly subjects (>75 years) in early stages of dementia were measured with the aim of gathering baseline data on healthy subject in our local population and exploring age and sex differences in urine 8-iPGF₂α. A stable deuterium labeled isotope-, 8-iso-prostaglandin (8-iPGF₂α-d4), was used as internal standard (IS) in the developed LC-MS/MS method. The method showed good linearity and LC separation, there was excellent recovery from aqueous solutions, and no ion suppression was seen. However, but the method was found to be insufficiently sensitive (limit of quantitation 125 pg/ml, in contrast to a desired value of <10 pg/ml) due to a combination of poor recovery of 8-iPGF₂α and 8-iPGF₂α-d4 (IS) from the urine matrix and inadequate sensitivity of the mass spectrometer used. Because of the methodological limitations, the data obtained in the 'clinical' part of the study have to be regarded as very preliminary. In 91 urine samples from healthy individuals, urinary creatinine adjusted 8-iPGF₂α level ranged from 88-2217 ng/g creatinine (or 28-707 pmol/mmol creatinine). Furthermore, results showed that the younger age group (aged 20-40) had slightly but significantly higher concentrations than frail elderly subjects (aged>75). No male-female difference was seen in urinary creatinine adjusted 8-iPGF₂α level in healthy subjects, nor was any difference seen between younger (aged 20-40 years) and middle (aged 41-65 years) healthy subjects. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b23992190.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.01 MB | Adobe PDF | View/Open |
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