Mammals chromatography

Analytical methods exist for measuring heptachlor, heptachlor epoxide, and/or their metabolites in various tissues (including adipose tissue), blood, human milk, urine, and feces. The common method used is gas chromatography (GC) coupled with electron capture detection (ECD) followed by identification using GC/mass spectrometry (MS). Since evidence indicates that heptachlor is metabolized to heptachlor epoxide in mammals, exposure to heptachlor is usually measured by determining levels of heptachlor epoxide in biological media. A summary of the detection methods used for various biological media is presented in Table 6-1. 

BDE 17, 28, 47, 66, 85, 99, 100, 153, 154 183 Adipose tissues from marine mammals, chicken and trout Adipose Tissues, chicken and trout MSPD with silica gel/anhydrous sodium sulfate powder, purification thorug GPC extraction with 400 mL of 1 1 (v/v) acetone/hexane mixture Gas Chromatography (VF-5MS Eactor Eour, Varian) IT-MS 0.07-1.3 pg (instrumental limit of detection) [42]... 

DL Hayteas, DA Duffield. Use of high-performance liquid chromatography for the estimation of polychlorinated biphenyls and p,p -DDE residues in marine mammals. J Chromatogr B 705 362-366, 1998. 

Wiberg, K. Letcher, R. Sandau, C. Duffe, J. Norstrom, R. Haglund, P. Bidleman, T. Enantioselective gas chromatography/mass spectrometry of methylsulfonyl PCBs with apph-cation to Arctic marine mammals Anal Chem. 1998, 70, 3845-3852. 

It was found that the most abundant congeners B8-1413 (P-26) and B9-1679 (P-50) were nearly racemic, even in tissue from the top level of aquatic food webs such as marine mammals and birds. A few studies, however, mentioned that enantiomer ratios of less persistent toxaphene components significantly deviated from 1.0 [239,242,243]. However, the enantioseparation of less abundant components in sample extracts is more difficult than that of B8-1413 (P-26) and B9-1679 (P-50). Suitable strategies to avoid compound interferences are preseparation by liquid chromatography, multidimensional GC, and MS/MS. 

To investigate thiamine metabolism in mammals, thiamine (Rf values 0.16, 0.04, and 0.03), urinary excretion of thiamine metabolites [thiochirome (Rf values 0.31, 0.28, and 0.33), thiazole (Rf values 0.85, 0.79, and 0.81), and 2-methyl-4-amino-pyrimidinecarboxylic acid (Rf values 0.42, 0.21, and 0.26)], and related compounds [pyrimidinesulfonic acid (Rf values 0.48, 0.39, and 0.46), a-hydroxyethylthiamine (Rf values 0.23, 0.09, and 0.06), A -methylnicotinamide (Rf values 0.31, 0.06, and 0.05)] were analyzed and identified by TLC on silica gel with acetonitrile-water (40 10 vol/vol) adjusted to a pH of 2.54, 4.03, and 7.85 with formic acid as solvents, respectively.Although A -methylnicotinamide and thio-chrome could not be separated in single-phase chromatography at pH 2.54, a second phase at right angle, with a pH 4.03 solvent, separated these quite clearly without affecting the resolution of the other compounds. 

The concentrations of the three arsenicals (75-77) were determined in 37 marine organisms comprising algae, crustaceans, bivalves, fish and mammals by high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS) [170]. All three organoarsenics, which occurred at pg/kg concentrations, were detected in 25, 23 and 17 of the 37 samples analyzed, respectively. The limits of detection were 2-3 pg/kg dry mass. The data illustrate that all three compounds are common minor constituents in practically all marine samples. 

The development of methods for separating lipid substances from natural sources has opened up new aspects in this field, (a) The use of chromatography has led to rapid and exact separation of compounds on a preparative scale, as well as in micro quantities, (b) It was found that, in tissues other than the central-nervous material (of mammals), there exists a group of glycosphingolipids having a sulfate group. 

Since bile alcohols in mammals may be present in unconjugated form or as glucuronides or sulfate esters, studies of these compounds require techniques for group separation of the different forms. Ion-exchange chromatography has been used for this purpose [77-79]. Bile alcohol glucuronides may be deconjugated by... 

W Goessler, A Rudorfer, EA Mackey, PR Becker, KJ Irgolic. Determination of arsenic compounds in marine mammals with high performance liquid chromatography and an inductively coupled plasma mass spectrometer as element specific detector. Appl Qrganomet Chem 12 491-501, 1998. 

Hamase K, Morikawa A, and Zaitsu K (2002) o-Amino acids in mammals and their diagnostic value. Journal of Chromatography B 781 73-91. 

The chitinolytic activity in extracts of the gastric mucosa from a prosimian mammal Perodicticus potto) has been purified by chromatography on colloidal chitin and by gel chromatography. The purified enzyme appears to be a specific chitinase. Procedures have been described for the isolation of chitinases from the pancreas and gastric mucosa of frogs [Rana temporaria temporaria). Precautions were taken to avoid denaturing the enzyme, whose behaviour on polyacrylamide gel electrophoresis was examined. 

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