High sensitive determination of oxysterols in human plasma using gas chromatography-mass spectrometry (GC-MS)
Journal Title: Journal of Analytical Bio-Science - Year 2012, Vol 35, Issue 2
Abstract
Oxysterols, cholesterol oxidation products, have been important markers for various diseases. For example, it is suggested that 24S-hydroxycholesterol, 27-hydroxycholesterol and 7-ketocholesterol can be used as a marker of Alzheimer's disease, cerebrotendinous xanthomatosis and diabetes mellitus, respectively. Therefore, it is necessary to determine the concentration levels of individual oxysterols in plasma. In this report, we have described a pretreatment procedure of human plasma for the simultaneous determination of oxysterols using gas chromatography-mass spectrometry (GC-MS). Pretreatments were carried out as follows; extraction from lipoprotein, saponification by hydrolyzing oxysterols esters, extraction with n-hexane, solid-phase extraction to remove the large levels of cholesterol in plasma, elution of oxysterols from their solid-phase, and their derivatization by trimethylsilyl reagent. Twelve oxysterols were simultaneously determined using this pretreatment procedure and a GC-MS analysis. The procedure is a simple and useful one for application to human plasma.
Authors and Affiliations
Saori Nakagawa, Susumu Yamato
Influence of NaCl on a protein error in the presence of detergent
Influence of NaCl on the color development of protein error in the presence of detergent was investigated using three dyes (BPB, BCG and BCP) and detergents (Brij 35, Triton X-100 and Tween 20). The influence of NaCl on...
A study on simultaneous measurement method for both platelets and fragmented red cells using flow-cytometric immunoplatelet count
Simultaneous measurement of both platelets and fragmented red cells (FRCs) using the flow-cytometric immunoplatelet (CD41/CD61) count was attempted. FRCs were prepared artificially by heating. The ICSH/ISLH immunoplatele...
Metabolism of retinyl esters in humans after ingestion of retinol
Using high-performance liquid chromatography, we determined which retinyl esters predominately circulate in human serum after the ingestion of rapeseed oil and a few drops of retinyl palmitate. Fatty acids, predominately...
Monomeric sarcosine oxidase acts on both L- and D-substrates
The stereoselectivity of monomeric sarcosine oxidase (mSox), an enzyme used for creatinine determination, was assayed by using N-methylalanine and proline. As a result, mSox reacted to both L- and D-substrates, although...
Essential knowledge of carnitine and carnitine deficiency
Carnitine is produced endogenously in the kidneys and liver, and is enriched in mutton and beef. It plays essential roles in the transportation of long-chain fatty acids into the mitochondria for beta-oxidation, in the e...