Analytical Sciences, 1897 Building, The Dow Chemical Company, Midland, Michigan 48667, USA.
J Agric Food Chem. 2010 Jun 9;58(11):6614-20. doi: 10.1021/jf101146q.
F(2)-isoprostanes are a unique class of prostaglandin-like compounds formed in vivo, which have been established as biomarkers of oxidative stress. Accurate analysis has been challenging due to lack of specificity for the isoforms of isoprostanes and lengthy sample preparation procedures to enable trace quantitative analysis. A quantitative analytical method was developed for the determination of F(2)-isoprostanes in rat and hamster urine by online solid phase extraction (SPE) coupled with liquid chromatography and tandem mass spectrometry (LC-MS/MS). The online SPE LC-MS/MS procedure has significant advantages over alternative methods with respect to specificity, sensitivity, simplicity, and speed. The assay enables the detection of iPF(2alpha)-III, iPF(2alpha)-IV, and iPF(2alpha)-VI over a linear dynamic range of 0.1-50 ng/mL in rat urine samples. This range covers the basal levels of these F(2)-isoprostanes. The limit of quantitation (LOQ) for the standard isoprostanes was about 0.3 ng/mL. The average recoveries ranged from 73 to 115% depending upon the individual F(2)-isoprostane isomers in rat urine. Additionally, the method was used to determine increases of endogenous urine iPF(2alpha)-VI and iPF(2alpha)-III in hamsters challenged with either low-fat or high-fat diets.
F(2)-同型前列腺素是体内形成的一类独特的前列腺素样化合物，已被确立为氧化应激的生物标志物。由于同型前列腺素异构体缺乏特异性和痕量定量分析所需的冗长样品制备程序，因此其准确分析一直具有挑战性。本研究建立了一种通过在线固相萃取（SPE）与液相色谱和串联质谱（LC-MS/MS）联用测定大鼠和仓鼠尿液中 F(2)-同型前列腺素的定量分析方法。与替代方法相比，在线 SPE LC-MS/MS 程序在特异性、灵敏度、简单性和速度方面具有显著优势。该测定法可在大鼠尿液样品中检测到 iPF(2alpha)-III、iPF(2alpha)-IV 和 iPF(2alpha)-VI 的线性动态范围为 0.1-50ng/mL。该范围涵盖了这些 F(2)-同型前列腺素的基础水平。标准同型前列腺素的定量下限（LOQ）约为 0.3ng/mL。根据大鼠尿液中个别 F(2)-同型前列腺素异构体的不同，平均回收率在 73%至 115%之间。此外，该方法还用于测定低脂或高脂饮食挑战的仓鼠内源性尿液 iPF(2alpha)-VI 和 iPF(2alpha)-III 的增加。
