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M M Krahn

Publications and source records attributed to M M Krahn.

25 records · Page 2Linked to original sources
PubMed1984

Determination of metabolites of xenobiotics in the bile of fish from polluted waterways.

An h.p.l.c.-fluorescence technique was used to estimate relative concentrations of metabolites of xenobiotics in bile of 103 English sole (Parophrys vetulus) from both polluted and minimally polluted (reference) sites in Puget Sound, WA. Fish from polluted sites had concentrations of xenobiotics in bile with naphthalene-, phenanthrene- and benzo[a]pyrene-like fluorescence that averaged 9, 14 and 19 times, respectively, those of fish from reference sites. Within a polluted site, fish with liver lesions had significantly higher bile concentrations of xenobiotics with benzo[a]pyrene-like fluorescence than did fish without liver lesions. Individual metabolites of fluorene, phenanthrene, anthracene, biphenyl and dimethylnaphthalene were determined by g.l.c.-mass spectrometry in extracts of hydrolysed bile of three English sole from polluted waterways; concentrations ranged from 90 to 19000 ng/g, wet wt. Other xenobiotics were tentatively identified, but not quantified.

Animals↗
PubMed1982

Gas chromatographic-mass spectrometric determination of aromatic hydrocarbon metabolites from livers of fish exposed to fuel oil.

Metabolites of several two- and three-ring aromatic hydrocarbons (AHs) have been found in livers of English sole exposed to No. 2 fuel oil. Four metabolites of the C2H5-naphthalenes, six of the C3H7-naphthalenes and one each of fluorene, phenanthrene and anthracene have been partially characterized and their concentrations, which ranged from 50 to 1100 ng/g, were determined. Metabolites were separated from the liver matrix using an automated extractor/concentrator. The resulting extract was then purified by high-performance liquid chromatography, and the metabolites were characterized and quantitated by gas chromatography-mass spectrometry.

Animals↗
PubMed1982

Aromatic hydrocarbon metabolites in fish: automated extraction and high-performance liquid chromatographic separation into conjugate and non-conjugate fractions.

An automated extractor-concentrator was used to extract metabolites of naphthalene, 2,6-dimethylnaphthalene, and benzo[a]pyrene from serum, bile and liver homogenate of rainbow trout (Salmo gairdneri). The extracts were analyzed by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. Recoveries of naphthalene and 2,6-dimethylnaphthalene metabolites from all matrices were generally greater than 90%; however, the recoveries of benzo[a]pyrene metabolites from serum ranged from 37-99%. In addition, conjugated metabolites of polycyclic aromatic hydrocarbons (PAHs) were separated from non-conjugated metabolites and parent PAHs by using two diol columns with normal-phase HPLC. The extraction and separation techniques were also applied to isolate metabolites in samples from fish fed 2,6-dimethylnaphthalene.

Animals↗
PubMed1980

Rapid analysis of naphthalene and its metabolites in biological systems: determination by high-performance liquid chromatography/fluorescence detection and by plasma desorption/chemical ionization mass spectrometry.

A rapid procedure for the determination of naphthalene and its metabolites in bile of rainbow trout and mice is described. The integrated analytical techniques combine high-performance liquid chromatography/ultraviolet fluorescence detection and plasma desorption/chemical ionization mass spectrometry for identification and quantitation. After separation by reverse-phase liquid chromatography, naphthalene and its metabolites are detected and quantitated by ultraviolet fluorescence spectrometry. Identification of two metabolites is confirmed by mass spectrometry. A direct insertion probe tip for a conventional chemical ionization mass spectrometer was modified to obtain spectra of thermally labile compounds. A spectrum of less than 100 ng of naphthyl glucuronide, a labile glucuronic acid conjugate of 1-naphthol, was obtained with this system.

Animals↗
PubMedDate not supplied

Uptake of aromatic and chlorinated hydrocarbons by juvenile chinook salmon (Oncorhynchus tshawytscha) in an urban estuary.

A study was conducted to assess the potential for uptake of toxic chemicals by down-stream migrant salmon in an urban estuary. Juvenile chinook salmon (Oncorhynchus tshawytscha) were collected from the Duwamish Waterway (located in Seattle, Washington) and from the Nisqually River (a reference site). The mean concentrations of aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in the stomach contents (food organisms) of salmon from the Duwamish Waterway were approximately 650 times and 4 times, respectively, higher than those in salmon from the Nisqually River. Similarly, the mean concentration of bile metabolites of aromatic compounds which fluoresce at benzo[a]pyrene wavelengths was 24 times higher in the urban salmon compared to the reference salmon, whereas the mean concentration of PCBs in liver of urban salmon was 3 times higher than that in reference salmon. The study clearly demonstrated that, during their residency in this urban estuary, juvenile chinook salmon bioaccumulate substantial levels of toxic chemicals. The possible effects of these chemical exposures on the health and survival of this species are not presently known.

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