SIMULTANEOUS DETERMINATION OF 8 LIPID-PEROXIDATION DEGRADATION PRODUCTS IN URINE OF RATS TREATED WITH CARBON-TETRACHLORIDE USING GAS-CHROMATOGRAPHY WITH ELECTRON-CAPTURE DETECTION

One of the major processes that occur as a result of radical-induced o xidative stress is lipid peroxidation (LPO). Degradation of lipid pero xides results in various products, including a variety of carbonyl com pounds. In the present study eight different lipid degradation product s, i.e., formaldehyde, acetaldehyde, acetone, propanal, butanal, penta nal, hexanal and malondialdehyde were identified and measured simultan eously and quantitatively in rat urine after derivatization with 0-(2, 3,4,5,6-pentafluorbenzyl)hydroxylamine hydrochloride, extraction with heptane and using gas chromatography-electron-capture detection (GC-EC D). The identity of the respective oximes in urine was confirmed by ga s chromatography-negative ion chemical ionization mass spectrometry (G C-NCI-MS). Simultaneously measured standard curves were linear for all oxime-products and the detection limits were between 39.0+/-5.3 (n=9) and 500+/-23 (n=9) fmol per mu l injected sample. Recoveries of all p roducts from urine or water were 73.0+/-5.2% and higher. In urine of C Cl4-treated rats an increase in all eight lipid degradation products i n urine was found 24 h following exposure. ACON showed the most distin ct increase, followed by PROPA, BUTA and MDA. It is concluded that the rapid, selective and sensitive analytical method based on GC-ECD pres ented here is well suited for routine measurement of eight different l ipid degradation products. These products appear to be useful as non-i nvasive biomarkers for in vivo oxidative stress induced in rats by CCl 4. (C) 1997 Elsevier Science B.V.