Bile acids chromatography

Capillary electrophoresis employing chiral selectors has been shown to be a useful analytical method to separate enantiomers. Conventionally, instrumental chiral separations have been achieved by gas chromatography and by high performance liquid chromatography.127 In recent years, there has been considerable activity in the separation and characterization of racemic pharmaceuticals by high performance capillary electrophoresis, with particular interest paid to using this technique in modem pharmaceutical analytical laboratories.128 130 The most frequently used chiral selectors in CE are cyclodextrins, crown ethers, chiral surfactants, bile acids, and protein-filled... 

Y. Ito, T. Takeuchi, D. Ishii, M. Goto and T. Mizuno, Direct coupling of micro high performance liquid chromatography with fast atom bombardment mass spectrometry. II Application to gradient elution of bile acids, J. Chromatogr., 385 (1986) 201-209. 

Lucangioli, S. E., Rodriguez, V. G., Otero, G. C. E, and Carducci, C. N. (1998). Determination of related impurities of bile acids in bulk drugs by cyclodextrin-modified micellar electrokinetic chromatography./. Capillary Electrophor. 5, 139-142. 

Assay of bile acids was an essential tool for the early investigation of the enterohepatic circulation, and proved a focus of attention with the belief that serum bile-acid concentrations would provide a sensitive diagnostic test for liver disease. There are three fundamental assay types, based on enzymatic oxidation of a hydroxyl with linked NAD reduction, chromatographic separations and quantitation, encompassing both gas-liquid and high-performance liquid chromatography, and radioimmunoassay assays. 

K. D. R. Setchell, J. A. Ives, G. C. Cashmore and A. M. Lawson, On the homogeneity of stools with respect to bile-acid composition and normal day-to-day variations A detailed qualitative and quantitative study using capillary column gas chromatography-mass spectrometry, Clin. Chim. Acta, 1987, 162, 257. 

Batta AK, Salen G (1999) Gas chromatography of bile acids. J Chromatogr Biomed Sci Appl 723 1-16... 

Wang GF, Stacey NH, Earl J (1990) Determination of individual bile acids in serum by high performance liquid chromatography. Biomed Chromatogr 4 136-140... 

Keller S, Jahreis G (2004) Determination of underivatised sterols and bile acid trimethyl silyl ether methyl esters by gas chromatography-mass spectrometry-single ion monitoring in faeces. J Chromatogr Analyt Technol Biomed Life Sci 813 199-207... 

Stellaard F, Langelaar SA, Kok RM, Jakobs C (1989) Determination of plasma bile acids by capillary gas-liquid chromatography-electron capture negative chemical ionization mass fragmentography. J Lipid Res 30 1647-1652... 

Goto J, Watanabe K, Miura H, Nambara T, Iida T (1987) Trace analysis of bile acids by gas chromatography-mass spectrometry with negative ion chemical ionization detection. J Chro-matogr 388 379-387... 

Lee BL, New AL, Ong CN (1997) Comparative analysis of conjugated bile acids in human serum using high-performance liquid chromatography and capillary electrophoresis. J Chro-matogr Biomed Sci Appl 704 35-42... 

Alme B, Bremmelgaard A, Siovall J, Thomassen P (1977) Analysis of metabolic profiles of bile acids in urine using a lipophilic anion exchanger and computerized gas-liquid chromatography-mass spectrometry. J Lipid Res 18 339-362... 

Back P, Siovall J, Siovall (1974) Monohydroxy bile acids in plasma in intrahepatic cholestasis of pregnancy. Identification by computerized gas chromatography-mass spectrometry. Med Biol 52 31-38... 

Kawasaki T, Maeda M, Tsuji A (1983) Immobilized -hydroxysteroid dehydrogenase and dansyl hydrazine as a pre-labeling reagent for high-performance liquid chromatography with fluorescence detection of bile acids. J Chromatogr 272 261-268... 

Matthees, D.P. and Purdy, W.C., Naphthyldiazomethane as a derivatizing agent for the high-performance liquid chromatography detection of bile acids, Anal. Chim. Acta, 109, 161, 1979. 

Kazumo, T., Thin-layer chromatography of bile acids, Kagaku No Ryoiki Zokan, 64, 19, 1964. 

Hara, S. and Takeuchi, M., Systematic analysis of bile acids and their derivatives by thin layer chromatography, J. Chromatogr., 11, 565, 1963 Chem. Abs., 60, 838f, 1964. 

Anthony, W.L. and Beher, W.T., Color detection of bile acids using thin layer chromatography,. /. Chromatogr., 13, 570, 1964 Chem. Abs., 60, 13546c, 1964. 

Plasma and urine samples from atherosclerotic and control rats were comparatively analyzed by ultrafast liquid chromatography coupled with ion trap-time-of-flight (IT-TOF) MS (UFLC-IT/TOF-MS) (16). They identified 12 metabolites in rat plasma and 8 metabolites in rat urine as potential biomarkers. Concentrations of leucine, phenylalanine, tryptophan, acetylcar-nitine, butyrylcamitine, propionylcamitine, and spermine in plasma and 3-0-methyl-dopa, ethyl /V2-acety I -1. -argininate, leucylproline, glucuronate, A(6)-(A-threonylcarbonyl)-adenosine, and methyl-hippuric acid in urine were decreased in atherosclerosis rats ursodeoxycholic acid, chenodeoxycholic acid, LPC (06 0), LPC (08 0), and LPC (08 1) in plasma and hippuric acid in urine were increased in atherosclerosis rats. The altered metabolites demonstrated abnormal metabolism of phenylalanine, tryptophan, bile acids, and amino acids. Lysophosphatidylcholine (LPC) plays an important role in inflammation and cell proliferation, which shows a relationship between LPC in the progress of atherosclerosis and other inflammatory diseases. 

S. Scalia and D.E. Games, Determination of free bile acids in pharmaceutical preparation by packed column supercritical fluid chromatography, J. Pharm. Sci., 82 44 (1993). 

Before the advent of soft ionization techniques, the analysis of bile acids was long and tedious and needed large sample quantities. First, the bile acids had to be extracted from the biological fluid and separated by lipophilic ion exchange chromatography into four classes ... 

Cholesterol is one of the main components of cell membranes and has several functions in the body, including the synthesis of certain hormones such as vitamin D and bile acid. Over the years, gas chromatography has been used to characterize cholesterol and its derivatives. Thiam et al. [123] developed an isocratic CEC method that allows baseline separation of a complex mixture of cholesterol and 12 ester derivatives in less than 40 min. The use of a polymeric surfactant, poly(sodium N-undecanoyl-L-glycinate), in the CEC buffer reduced migration time and improved resolution of the analytes. 

Chromatography, Gas, in Determination of Bile Acids and Steroids (Kulcsis). 14 325... 

Chromatography.—Considerable attention is being paid to chromatographic methods for the separation and recognition of bile acids and their derivatives. The analysis (g.l.c.) of mixtures of bile acids and their conjugates is reported to be simplified by direct conversion into heptafluorobutyrate derivatives, which occurs with simultaneous deconjugation.The carboxyl function is apparently converted into its volatile mixed cholanyl-heptafluorobutyryl anhydride. Ethyl-dimethylsilyl ethers of bile acid ethyl esters are also reported to be suitable for... 

Gas-liquid chromatography Capillary GLC analysis of bile sterols and bile acid methyl esters (as their trimethylsilyl derivatives) was performed on Hewlett-Packard model No. 4890 (equipped with a flame ionization detector) and a split column injector using a CP sil 5 (CB) WCOT capillary colunm (25 m x 0.22 mm with 0.13-mm Him thickness). Helium was used as a carrier gas at a flow rate of 20.2 mL/min (135 kPa). 

Batta, A. K., Shefer, S., Batta, M., and Salen, G. (1985). Effect of chenodeoxycholic acid on biliary and urinary bile acids and bile alcohols in cerebrotendinous xanthomatosis monitoring by high performance liquid chromatography. J. Lipid Res. 26 690-698. 

Derivatives of alcohols. Treatment with hexamethyldisilazane in pyridine solution at room temperature converts bile acids and sugars into O-trimethylsilyl ethers, which are much more volatile than usual ethers and well suited for gas-liquid chromatography. 

Analytical techniques used to quantify either total or individual bile acids in biological fluids include gas-hquid chromatography (GLC), high-performance liquid chromatography (HPLC), enzymatic assay, radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), and tandem mass spectrometry (MS/MS). 

There are several methods available for the extraction of bile salts from serum or plasma. The most convenient methods utilize some form of liquid-solid extraction. An early procedure involved the anion-exchange resin, Amberlyst A-26 (S8), but considerable time and effort was required to perform column chromatography and to concentrate the eluate from the column. The introduction in 1972 of the neutral resin, Amberlite XAD-2, improved the ease of extracting bile acids and their conjugates from serum samples (M6). Further improvement occurred in 1977 with the description of a batch extraction technique using the related neutral resin, Amberlite XAD-7 (B5). With this technique, serum is diluted in 0.1 M sodium hydroxide to release bile acids from albumin and mixed with resin for 1 hour. After washing the resin in dilute alkali, bile acids are eluted with methanol, which cdn be removed on a rotary evaporator (B5). 

To deconjugate bile acids for further analysis, particularly by gas-liquid chromatography, different methods are required for the hydrolysis of the peptide bonds in glycine and taurine conjugates than for hydrolysis of the ester sulfate and glucuronide bonds. Glycine and taurine may be removed by either alkaline or enzymatic hydrolysis (Rll). Alkaline hydrolysis is often... 

Gas-liquid chromatography is a well established and widely used method for the analysis of individual bile acids. In addition to its sensitivity, this technique has the advantage of simultaneous separation of complex bile acid mixtures and their quantification, usually by flame ionization detection. When combined with mass spectrometry, unequivocal identification of unknown bile acids can be achieved. Thus, this method is regarded as the reference method against which other methods are compared. However, GLC is laborious and time consuming and needs considerable expertise on the part of technical staff for good results. 

---