Reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) method using two 15cm sub-2μm particles octadecylsilica gel columns is developed with the goal to separate and unambiguously identify a large number of lipid species in biological samples. The identification is performed by the coupling with high-resolution tandem mass spectrometry (MS/MS) using quadrupole - time-of-flight (QTOF) instrument. Electrospray ionization (ESI) full scan and tandem mass spectra are measured in both polarity modes with the mass accuracy better than 5ppm, which provides a high confidence of lipid identification. Over 400 lipid species covering 14 polar and nonpolar lipid classes from 5 lipid categories are identified in total lipid extracts of human plasma, human urine and porcine brain. The general dependences of relative retention times on relative carbon number or relative double bond number are constructed and fit with the second degree polynomial regression. The regular retention patterns in homologous lipid series provide additional identification point for UHPLC/MS lipidomic analysis, which increases the confidence of lipid identification. The reprocessing of previously published data by our and other groups measured in the RP mode and ultrahigh-performance supercritical fluid chromatography on the silica column shows more generic applicability of the polynomial regression for the description of retention behavior and the prediction of retention times. The novelty of this work is the characterization of general trends in the retention behavior of lipids within logical series with constant fatty acyl length or double bond number, which may be used as an additional criterion to increase the confidence of lipid identification.

• Klíčová slova
• Human plasma, Lipidomics, Lipids, Mass spectrometry, Retention behavior, Ultrahigh-performance liquid chromatography,
• MeSH
• časové faktory MeSH
• chromatografie s reverzní fází metody   MeSH
• erytrocyty chemie   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• lidé MeSH
• lipidy analýza   krev   chemie   moč   MeSH
• mozek - chemie MeSH
• prasata MeSH
• superkritická fluidní chromatografie MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lipidy MeSH

A fast and simple method for determination of sulfatides in the urine of patients with metachromatic leukodystrophy (MLD, arylsulfatase A deficiency) has been developed. The procedure consists of two steps: extraction of total urinary lipids by reversed-phase chromatography and their HPTLC separation. Two types of sorbents based on different matrixes were compared, of which the hydroxyethyl methacrylate C-18 type sorbent was found to be superior. Twenty-milliliter aliquots of urine are sufficient for the analysis. The technique is appropriate for simultaneous qualitative identification and semiquantitative densitometric determination and is suitable for routine work. The amount of sulfatides is expressed in relation to sphingomyelin, which copurifies with sulfatides and better reflects the level of membrane lipids in urine than commonly used parameters (creatinine, urine volume, etc.). The ranges were found to be 0.15-0.68 nmol sulfatide/nmol sphingomyelin for control individuals and 3.5-27.2 nmol sulfatide/nmol sphingomyelin for MLD patients. The excretion of sulfatides is pathonognomic for true MLD (due to the accumulation in kidney) and therefore its analysis is important for evaluation of suspected MLD cases including clinically and enzymatically atypical cases. The method is also useful as a complementary analysis for other lipidoses with high excretion of sphingolipids in urine (e.g., Fabry disease).

• MeSH
• chromatografie na tenké vrstvě metody   MeSH
• chromatografie metody   MeSH
• Fabryho nemoc moč   MeSH
• lidé MeSH
• lipidy moč   MeSH
• metachromatická leukodystrofie diagnóza   moč   MeSH
• proteinurie moč   MeSH
• studie případů a kontrol MeSH
• sulfoglykosfingolipidy moč   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• lipidy MeSH
• sulfoglykosfingolipidy MeSH

The effect of lipophilicity on the renal clearance for a group of weak organic acids (benzoic, phenylacetic and hippuric acid derivatives) was studied in rabbits, rats and mice. These compounds are eliminated in the kidney by glomerular filtration and undergo both tubular secretion and tubular reabsorption. For quantification of the effect of lipophilicity, an equation [formula: see text] was employed, where CLR represents renal clearance of the parent drug, ERPF is effective renal plasma flow, D is the partition coefficient of the acids between octanol and water, and a and b are constants. In interspecies comparison, the values of parameters a and b are similar indicating no significant interspecies differences in this route of elimination.

• MeSH
• činčila MeSH
• inbrední kmeny potkanů MeSH
• králíci MeSH
• krevní proteiny metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyseliny chemie   moč   MeSH
• ledviny metabolismus   MeSH
• lipidy chemie   moč   MeSH
• myši MeSH
• renální oběh MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• krevní proteiny MeSH
• kyseliny MeSH
• lipidy MeSH