Hydrogen, carbon monoxide, and methane in the marine environment

EXTRACT (SEE PDF FOR FULL ABSTRACT): The horizontal and vertical distribution of three dissolved trace gases, namely molecular hydrogen, carbon monoxide, and methane, was measured in coastal and oceanic areas. Atmospheric concentrations of these gases were measured both at locations influenced by nearby human activity, and in areas far removed from these inputs.

Entwicklung einer einfachen und schnellen Analysenmethode für Kohlenmonoxid in Fisch und Durchführung orientierender Untersuchungen

Treatment with gases containing CO, misleadingly called “tasteless smoke” or “clear smoke”, prior to freezing of fish like tuna, tilapia and swordfish (to name only a few of these species that are characterised by an intensive coloration of flesh) stabilise the fresh red colour of muscle also after thawing and suggest consumers non-existing freshness. In the European Union, carbon monoxide is excluded from being a permitted additive and therefore this handling is not allowed. Notwithstanding of the clear legal position, producers and traders are trying to establish CO treated fish on the market. In the case of taking legal measures the food control laboratories have to provide evidence that fish has been treated by CO and therefore a respective method is necessary. The method of determination of carbon monoxide in fish flesh presently applied requires considerable material and mechanistic effort to detect CO by GC after catalytic transformation into methane. The aim of our work was a direct detection of CO using suitable sensor technology. Mechanistic requirements and results of preliminary investigations to detect carbon monoxide in fish flesh will be described.

Entwicklung einer einfachen und schnellen Analysenmethode für Kohlenmonoxid in Fisch – Teil 2: Methodenoptimierung

After having described in our first paper (Haase et al. 2005) the main features of an easy and fast method for determination of carbon monoxide in fish and the equipment and chemicals necessary as well as first results measured on fish samples, this part deals with the influence of sample preparation, variation of the size of samples, type of solvent, duration of extraction and further conditions on the result of analyses. Both variants of the method are evaluated with regard to measuring expected errors. The single components of the equipment, including prises, are listed to allow a reliable assessment of costs. Additional instrumental colour and DSC measurements on both untreated and CO-treated tuna illustrate the effects.

Organic carbon in the sediments of the lower reaches of Periar River

Sediments are indicators of the quality of water overlying them and hence, useful in the assessment of environmental pollution. Temporal and spatial variations in sediment characteristics and organic carbon content from 9 stations in the lower reaches of Periyar River an area in Cochin Backwater, India which is polluted from different sources were studied for one year during 1981. Variations in colour and texture of sediments were brought about by changes in the grain size and state of oxidation of organic matter. The colour of the sediment varied from greyish black at stations 1 and 2, brownish at station 3, black at stations 4 to 8 and reddish at station 9. Organic carbon and sediment texture showed a direct relationship at all stations except at station 9 where organic carbon content showed an irregular pattern. Overall range of organic carbon content was between 1.19 and 29.6 mg.g super(-1). The mean organic carbon of the stations ranged between 6.8 mg.g super(-1) (station 5) and 20.8 mg.g super(-1) (station 9). On the whole temporal variations were considerable with high values at station 9 and low values at station 5. Fluctuations were more at stations 6, 7 and 8.