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Biomedical subjects

D H Fine

Publications and source records attributed to D H Fine.

At least 91 records · Page 5Linked to original sources
PubMed1980

Nitrosamines in new automobiles.

The volatile nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), N-nitrosodiethylamine (NDEA) and possibly N-nitrosodibutylamine (NDBA) have been found to be present as airborne pollutants in the interiors of new (1979 model) automobiles. In the 38 automobiles tested, the levels ranged from 0.07 to 0.83 micrograms/m3 (average 0.3 micrograms/m3) for NDMA, from 0.07 to 2.5 micrograms/m3 (average 0.67 micrograms/m3) for NMOR, from 0.04 to 0.39 micrograms/m3 (average 0.11 micrograms/m3) for NDEA and trace levels (less than 0.01 micrograms/m3) for NDMA.

Air Pollutants↗
PubMed1979

N-nitrosamines in the rubber and tire industry.

Airborne N-nitrosomorpholine (0 to 27 micrograms per cubic meter) was found in two of four rubber industry factories. N-Nitrosodimethylamine was also found in two factories, but at lower levels. These findings may be relevant to the reported increased risk of certain types of cancer in rubber workers in some of the same areas where the N-nitrosomorpholine levels were highest.

Air Pollutants↗
PubMed1979

N-Nitroso compound contaminants in prescription and nonprescription drugs.

73 pharmaceutical products, consisteing of both prescription and over-the-counter drugs have been analyzed by gas chromatography-thermal energy analysis (GC-TEA) and high-pressure liquid chromatography-thermal energy analysis (HPLC-TEA) for the presence of N-nitroso compound contaminants. The methods used were designed to detect both volatile and non-volatile N-nitroso compounds at levels down to 1 ng/g (1 ppb). Results presented here indicate that N-nitroso compound impurities are absent from the majority of the products tested. However, for 3 of the drugs, our analysis suggests the possible presence of N-nitroso compounds at levels up to 81 ng/g (81 ppb). The identity of the suspect N-nitroso compounds have not yet been established. In the case of the over-the-counter drugs, two of these have been shown to contain TEA responsive materials (126 ppb, 406 ppb), that may appear to be O-nitroso compounds rather than N-nitroso.

Chemical Phenomena↗
PubMed1978

An assessment of human exposure to N-nitroso compounds.

Current knowledge on human exposure to N-nitroso compounds is reviewed. Four exposure routes are considered: ingestion, inhalation, dermal and in vivo. The relative importance of various N-nitrosation mechanisms is discussed.

Administration, Topical↗
PubMed1978

Comprehensive analytical procedures for the determination of volatile and non-volatile, polar and non-polar N-nitroso compounds.

The first comprehensive analytical procedures for the quantitative analysis of N-nitroso compounds are described. The scheme divides N-nitroso compounds into four major, overlapping categories: volatile (Class I), non-volatile, low polarity (Class II), non-volatile, non-ionic, high polarity (Class III) and non-volatile, ionic, high polarity (Class IV). Existing analytical techniques for each class of compound are integrated into an organized and logical sequence of analysis to allow all classes of compounds to be determined. TEA-GC is used for the volatile compounds and TEA-HPLC for the non-volatile. It is emphasized that the coincidence of retention time in either TEA-GC alone or TEA-HPLC alone cannot be taken as sufficient evidence for the identification of N-nitroso compounds, especially for samples from complex matrices. Independent techniques are required to confirm these results. The confirmatory techniques used frequently in our laboratory are: (1) spectroscopic analysis (IR, NMR, UV and MS), (2) formation and identification of derivatives, and (3) parallel TEA-GC/TEA-HPLC techniques. These procedures are now used at Thermo Electron for the comprehensive screening of environmental samples.

Chemical Phenomena↗
PubMed1977

Quantitation of dimethylnitrosamine in the whole mouse after biosynthesis in vivo from trace levels of precursors.

A simple and highly sensitive procedure is described for the recovery and quantitative identification of nanogram quantities of preformed N-nitroso compounds in the whole mouse. This procedure has also been applied to the quantitation of N-nitroso compounds after they have been biosynthesized from trace amounts of precursors. The whole animal is frozen in liquid nitrogen and homogenized to a frozen powder; the powder is then extracted and analyzed by a thermal energy analyzer interfaced to a gas-liquid and a high-pressure liquid chromatograph.

Animals↗
PubMed1977

N-Nitrosodiethanolamine in synthetic cutting fluids: a part-per-hundred impurity.

N-nitrosodiethanolamine has been found to be present at a concentration of 0.02 to 3 percent in several brands of synthetic cutting fluids. Its identity was confirmed by three independent techniques: (i) by measuring the retention times on two different high-performance liquid-chromatography columns, (ii) by dehydration to N-nitrosomorpholine, and (iii) by preparation of the O-methyl ether derivative.

Environmental Pollutants↗
PubMed1977

Affinity chromatography of antiserum to a gram negative organism.

An immunoadsorbent method is described for the purification of antibody directed against gram negative bacteria. Two anion exchange materials were compared for their ability to immobilize whole cells of Veillonella alcalescens, a gram negative oral bacterium. Purified antibody preparations were applied to the columns and subsequently eluted with various combinations of desorbing buffers. The quantity of recovered antibody was measured and its activity assayed, using a microagglutination technique. The highest levels of protein and specific antibody activity were recovered from Dowex-1-acetate columns desorbed by a combination of borate buffer pH 10 and 3 M KSCN pH 6, followed by levels of specific antibody activity obtained from a DEAE cellulose column desorbed by glycine--HC1, PBH 2.3.

Chromatography, Affinity↗