[The hypochondriac form of paranoia].
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Humans↗
Biomedical subjects
E B Hansen
Publications and source records attributed to E B Hansen.
Characterization of the antihistamines tripelennamine, methapyrilene, and thenyldiamine and their N-oxides by thermospray mass spectrometry.
This study describes an investigation of the thermospray (TS) mass spectrometric analysis of tripelennamine, methapyrilene, thenyldiamine, and their N-oxide derivatives. These compounds were analyzed by direct injection TS mass spectrometry in the column bypass mode and with 0.1M ammonium acetate/methanol (80:20, v/v) as the mobile phase. Typically, the parent antihistamines produced only [MH]s ions under these conditions. The N-oxides provided strong [MH]s ions and multiple fragment ions. A scheme to explain the fragmentation patterns is proposed.
Aminopyridines↗
Application of HPLC-thermospray ionization mass spectrometry for the analysis of triprolidine and its metabolite hydroxymethyltriprolidine in biological samples.
High-performance liquid chromatography coupled to positive ion mode thermospray ionization mass spectrometry has been used to characterize triprolidine and its known metabolite hydroxymethyltriprolidine. The method allows direct analysis of these compounds in complex biological matrices. Analysis of an extract from a microbial biotransformation experiment with triprolidine was performed and the results included two baseline-resolved chromatographic peaks. The [M + H]+ ion obtained from the mass spectrum of the first peak was consistent with that of hydroxymethyltriprolidine, and the mass spectrum of the second peak corresponded to triprolidine. Under the described conditions, the minimum detectable level of triprolidine without filament enhancement was estimated at about 10 micrograms injected on column.
Chromatography, High Pressure Liquid↗
Determination of triethylenetetramine dihydrochloride in aqueous solution by reversed-phase ion-pairing high performance liquid chromatography and conductivity detection.
Triethylenetetramine dihydrochloride (TETA) has been used for the treatment of Wilson's disease which is a metabolic disorder that prevents its victims from eliminating excess copper. TETA was scheduled for toxicological evaluation because of a deficiency of such information. Analytical chemical procedures to determine the purity of the drug as well as the proper concentration and stability of the drug in dosed water were prerequisites for the toxicological tests. A high performance liquid chromatography (HPLC) procedure employing ion-pairing and conductivity detection has been developed for the analysis of TETA in dosed water at levels as low as 10 micrograms/mL and for the determination of drug purity. The conductivity detector response was linear over the concentration range of 10 to 100 micrograms/mL. Data are presented concerning the stability of the drug in water during ambient storage and after autoclaving. An ancillary colorimetric procedure for the analysis of aqueous TETA solutions is also presented which is based on measuring the absorbance of the colored TETA copper chelate at 599 nm. The HPLC procedure is applicable to the analysis of TETA and the chemically similar polyamines spermidine and spermine in admixture.
Animals↗
Microbial transformation of the antihistamine pyrilamine maleate. Formation of potential mammalian metabolites.
Fourteen fungi were found to metabolize pyrilamine (2-[(2-dimethylaminoethyl)(p-methoxybenzyl)amino]pyridine). Two Cunninghamella elegans strains transformed essentially all of the pyrilamine added after 144 hr. After 48 hr of incubation, C. elegans ATCC 9245 metabolized 76% of the antihistamine into methylene chloride-extractable pyrilamine metabolites. These organic-soluble metabolites were isolated by HPLC and the major metabolites were characterized by comparison of their chromatographic, mass, and 1H-NMR spectral properties with those of authentic compounds. The major metabolite was identified as 2-[(2-dimethyloxyaminoethyl)(p-methoxybenzyl)amino]pyridine (N-oxide derivative of pyrilamine). Other metabolites identified were 2-[(2-dimethylaminoethyl)(p-hydroxybenzyl)amino]pyridine, 2-[(2-methylaminoethyl)(p-methoxybenzyl)amino]pyridine, and 2-[(2-methylaminoethyl)(p-hydroxybenzyl)amino]pyridine. These metabolites represent O-demethylated, N-demethylated, and O- and N-demethylated derivatives of pyrilamine, respectively. The mutagenic activities of the N-oxide and the N- and O-dealkylated pyrilamine derivatives, and pyrilamine maleate were measured by reversion of Salmonella typhimurium strains TA97, TA98, TA100, and TA102. Pyrilamine maleate and the three microbial metabolites showed no appreciable mutagenic activity in any of the S. typhimurium tester strains. The metabolism of pyrilamine by 12 other filamentous fungi and yeast strains was much less when compared to C. elegans and ranged from 3.8% to 12.2%. The fungal metabolism of pyrilamine may be useful in predicting results of mammalian metabolism and in readily providing sufficient quantities of metabolites for further toxicological studies.
Aminopyridines↗
High temperature purge and trap procedure for determining seven volatile N-nitrosamines in animal feed, using gas chromatography/thermal energy analyzer.
A rapid and sensitive procedure is described for determining 4 N-nitrosodialkylamines (dimethyl, diethyl, dipropyl, and dibutyl) and the N-nitroso analogs of piperidine, pyrrolidine, and morpholine in animal feed. The volatile N-nitrosamines were isolated by using a modified high temperature purge and trap apparatus designed for multiple sample cleanup. The feed sample was mixed with mineral oil and a nitrosation inhibitor, and the N-nitrosamines were purged onto a ThermoSorb/N cartridge, eluted with acetone-dichloromethane (1 + 1), and determined by gas chromatography, using a thermal energy analyzer. The effects of purge rate, purge time, and temperature on recovery are discussed. Feed samples spiked with 10, 50, and 200 ppb of the 7 N-nitroso compounds yielded recoveries ranging from 70 to 97%, with precision ranging from 1.3 to 5.4% and minimum detectable levels in the low parts-per-billion range.
Animal Feed↗
Determination of lincomycin residue in salmon tissues by ion-pair reversed-phase liquid chromatography with electrochemical detection.
A method is described for detecting and quantitating lincomycin residue in salmon muscle and skin tissues by ion-pair reversed-phase liquid chromatography (LC) with electrochemical detection at +0.9 V. Lincomycin was extracted from tissues by homogenizing with 0.01 M KH2PO4 buffer (pH 4.5) and centrifuging the mixture. Water-soluble proteins were precipitated by adding sodium tungstate and sulfuric acid and removed by centrifugation. The buffer extract was then passed through a C18 solid-phase extraction cartridge. Lincomycin was eluted with 50% acetonitrile in water, and the eluate containing lincomycin was extracted with ethyl acetate. After the solvent had evaporated, the residue was redissolved in mobile phase and analyzed by LC. The method had a limit of detection of 7 ng/g lincomycin for salmon muscle and 12 ng/g for salmon skin. The limit of quantitation was 17 ng/g for salmon muscle and 24 ng/g for salmon skin. Average recoveries of lincomycin spiked at 50, 100, and 200 ng/g were > or = 85% for salmon muscle and > or = 80% for salmon skin.
Acetonitriles↗
Determination of amoxicillin in catfish and salmon tissues by liquid chromatography with precolumn formaldehyde derivatization.
A liquid chromatographic (LC) method with fluorescence detection was developed for analysis of amoxicillin in catfish and salmon tissues. The tissue was extracted with phosphate buffer (pH 4.5), followed by trichloroacetic acid (TCA) precipitation of proteins and solid-phase (C18) extraction. Trace amounts of nonpolar interfering substances present after solid-phase extraction were removed by ether liquid-liquid extraction. The extract was reacted with formaldehyde and TCA at 100 degrees C for 30 min. A fluorescent derivative was extracted with ether, concentrated, and analyzed by reversed-phase LC with fluorescence detection. Average recoveries of amoxicillin spiked at 2.5-20 ppb were > 80% for catfish and > 75% for salmon muscle tissue, with coefficients of variation of < 6%. Limits of detection (LOD) and quantitation (LOQ) for catfish tissue were 0.5 and 1.2 ppb, respectively. LOD and LOQ for salmon muscle tissue were 0.8 and 2.0 ppb, respectively.
Amoxicillin↗