ABSTRACT
Technetium is a man-made element produced in increasing amounts during the last decades. The chemical and physical properties of some technetium compounds are considered, and a discussion of possible source terms is included. Literature on the environmental behavior of technetium is reviewed to evaluate its transfer and equilibrium distribution in aquatic and terrestrial ecosystems. Considerable effort has been expended in the last years in order to understand the biogeochemical processes responsible for the long-term behavior of technetium in the environment and its transfer through food chains as well as to identify critical pathways of the long-lived radioisotope Tc-99 from the environment to man.
Subject(s)
Environmental Pollution , Technetium , Food Contamination, Radioactive , Humans , Nuclear Medicine , Nuclear Reactors , Nuclear Warfare , Soil Pollutants, Radioactive , Water Pollution, RadioactiveABSTRACT
A simple procedure is described for separation and analysis of adenine nucleotides in tissue extracts, utilizing anion exchange HPLC. Determination of AMP, ADP, and ATP takes 10 min per sample.
Subject(s)
Adenosine Diphosphate/isolation & purification , Adenosine Monophosphate/isolation & purification , Adenosine Triphosphate/isolation & purification , Animals , Bivalvia , Chromatography, High Pressure Liquid/methods , Energy Metabolism , MolluscaABSTRACT
The prawn Palaemon elegans, when exposed to seawater containing 95mTc0-4, accumulates technetium to a low extent (concentration factor less than 10). Release occurs following biphasic kinetics, most of the radioactivity being eliminated at a fast rate. Biological half-lives have been calculated for water temperatures of 10 degrees and 20 degrees C.
Subject(s)
Palaemonidae/metabolism , Technetium/metabolism , Animals , Half-Life , KineticsABSTRACT
Reversible binding of pertechnetate (95mTcO-4) by human serum albumin (HSA) has been investigated by "wash-in" experiments, in the presence of a large excess of HSA. Equilibrium constants have been determined in the range of temperature between 5 and 37 C. Thermodynamic parameters of the process have been calculated. The marked influence of temperature on the association reaction should be taken into consideration when carrying out investigations on the metabolism of technetium in poikilotherms.
Subject(s)
Serum Albumin/metabolism , Technetium/metabolism , Filtration/methods , Humans , Sodium Pertechnetate Tc 99m , TemperatureABSTRACT
The complexation of cadmium by isocitrate has been studied at 25 degrees C and pH 7.5 in a range of ionic strength from 0.01 to 0.16. The formation constant of the complex between cadmium and tribasic isocitrate varies from 860 M-1 at mu=0.16 to approximately 24,500 M-1 at infinite dilution. These data allow the distribution of the chemical forms of cadmium added to the incubation mixtures for tha assay of NAD-dependent isocitrate dehydrogenase to be calculated.
