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D W Arnold

Publications and source records attributed to D W Arnold.

12 recordsLinked to original sources
PubMed2000

Cost-benefit analysis of the use of TBT: the case for a treatment approach.

The current climate of hostility towards the use of tributyltin (TBT) as an active ingredient in ship anti-fouling paint appears to be based on a very biased assessment of its environmental impact. While many national and international regulatory agencies are moving towards further restriction, and a complete ban is under active discussion, a number of factors appear to have been ignored. The economic impact of a ban on TBT when no adequate substitute exists could be substantial. Environmentally, consequences would include a substantial increase in the consumption of fossil fuel, with corresponding increases in carbon dioxide and sulphur dioxide emissions; the construction of more vessels; the transfer of ship-building, ship-repairing and ship-breaking activities from well-regulated to unregulated or under-regulated areas in the developing world; and a shift from sea transport to less environmentally acceptable forms of transport. Experience in Europe and other parts of the developed world shows that existing restrictions, where they are properly enforced, are probably adequate to alleviate the environmental damage associated with TBT. Some existing legislation acts to inhibit the search for effective substitutes. The environmental benefits of TBT have been ignored. Little thought has been given to a technical, rather than a legislative solution to controlling TBT inputs to the environment. A method is described for treating TBT-contaminated wastewaters, which has been successfully tested in prototype at full scale. Legislative measures against TBT will do nothing to address the problem of the existing backlog of contaminated material, nor even to permit the IMO proposal for the removal of TBT from all ships by 2008 to be successfully concluded in an environmentally safe manner, since no provision has been made for the disposal of the existing TBT; most probably it will be dumped in environmentally sensitive, unregulated areas in the developing world.

Cost-Benefit Analysis↗
PubMed2000

On-chip chiral and achiral separation of amphetamine and related compounds labeled with 4-fluoro-7-nitrobenzofurazane.

Amphetamine and analogous compounds have been labeled with 4-fluoro-7-nitrobenzofurazane and analyzed on a microfabricated chip. Separation of norephedrine, ephedrine, cathinone, pseudoephedrine, methcathinone, amphetamine and methamphetamine is demonstrated using micellar electrokinetic capillary chromatography (MEKC) and laser-induced fluorescence (LIF) detection. Chiral separations of individual drugs were studied using neutral and negatively charged cyclodextrins (CDs) with and without the addition of an organic modifier and/or sodium dodecyl sulfate (SDS). The best results were obtained using a highly sulfated gamma-CD (HS-gamm-CD) in combination with a low concentration of SDS. To obtain complete separation of a mixture of (+/-)-norephedrine, (+/-)ephedrine, (+/-)-pseudoephedrine, (+/-)-methcathinone, (+/-)-amphetamine and (+/-)-methamphetamine it was necessary to add a small amount (1.5 mM) of SDS to the separation buffer. Optimized chiral separation was achieved within 7 min using an S-folded separation channel, a separation voltage of 8 kV and a buffer consisting of 50 mM phosphate (pH 7.35), 10 mM HS-gamma-CD and 1.5 mM SDS.

4-Chloro-7-nitrobenzofurazan↗
PubMed1999

SDS capillary gel electrophoresis of proteins in microfabricated channels.

Analysis of variations in the concentrations or structures of biomolecules (e.g., mRNAs, proteins, peptides, natural products) that occur either naturally or in response to environmental or genetic perturbations can provide important insight into complex biological processes. Many biological samples are mixtures that require a separation step before quantitation of variations in the individual components. Two-dimensional denaturing gel electrophoresis has been used very effectively to separate complex mixtures of proteins, but it is time consuming and requires considerable amounts of sample. Microchannel-based separations have proven very effective in rapidly separating small amounts of nucleic acids; more recently, isoelectric focusing of proteins also has been adapted to the microchannel format. Here, we describe microchannel-based SDS capillary gel electrophoresis of proteins and demonstrate the speed and high resolution it provides. This development is an important step toward the miniaturization and integration of multidimensional and array separation methods for complex protein mixtures.

Calmodulin↗
PubMed1977

Dominant lethal studies with technical chlordane, HCS-3260, and heptachlor: heptachlor epoxide.

Male albino mice in groups of eight were each given single doses, either by gavage or by intraperitoneal injection, of either technical chlordane (50 or 100 mg/kg), HCS-3260 (50 or 100 mg/kg), or heptachlor:heptachlor epoxide (25:75) (7.5 or 15 mg/kg). The males were subsequently mated with three untreated females for six consecutive weeks. No dominant lethal changes among females that had mated with the treated males were produced.

Animals↗
PubMed1975

Investigation of hexachlorophene for dominant lethal effects in the mouse.

Hexachlorophene (HCP) was studied for mutagenic effects in the dominant lethal test on mice. Groups of male mice were treated with either 2.5 or 5.0 mg hexachlorophene per kg body weight as a single intraperitoneal injection. Control animals were treated with the propylene glycol vehicle. Each male was mated with 3 untreated females for each of 8 consecutive weeks with the uterus of the females examined at mid-pregnancy for signs of early embryonic death. Treatment did not alter mating capacity and fertility of the males. The administration of hexachlorophene had no influence on pre- or post-implantation losses. An increase in early resorptions among female mice bred to males treated with the reference compound, methyl methanesulfonate (MMS) given a single i.p. injection of 100 mg/kg, indicated the susceptibility of the mouse strain used to a known mutagen. It is concluded that hexachlorophene at maximally tolerated doses is not mutagenic in the dominant lethal test in mice.

Animals↗