Scientific paper
Scientific paper
Optimization of a preparative capillary gas chromatography – mass spectrometry system for isolation and harvesting of individual PAHs.
Scientific paper
Induction of micronuclei in mouse and rat by glycidamide, genotoxic metabolite of acrylamide
Scientific paper
Nanoinjection as a tool to mimic vertical transmission of Flavobacterium psychrophilum in rainbow trout Oncorhynchus mykiss
egg
,
flavobacterium psychrophilum
,
nanoinjection
,
rainbow trout
,
rtfs
Newly fertilised eggs of rainbow trout Oncorhynchus mykiss were nanoinjected with Flavobacterium psychrophilum in order to mimic vertical transmission. Two bacterial isolates with different elastin-degrading capacity were used. All infected groups (10, 100 and 1000 colony forming units egg(-1)) showed significantly higher cumulative mortalities than the control groups at the end of the experiment, 70 d post-hatching. The total mortalities in the control groups were below 2.5%. In the high-dose groups, 95 to 100% of the eggs died during the eyed stage. In the intermediate group infected with the elastin-negative isolate, the major mortality occurred during the eyed stage of the egg, with a total cumulative mortality of 83% at the end of the experiment. In the intermediate group infected with the elastin-positive isolate, a total mortality of 63% was recorded. In this group, diseased fry showed clinical signs of disease and morphological changes similar to those described in connection with rainbow trout fry syndrome (RTFS) shortly after the beginning of feeding, In the low dose groups, the mortality in the elastin-negative group was 14% and in the elastin-positive group 11%. The bacterium was isolated from dead eggs and fry in infected groups and demonstrated in internal organs of dead and moribund fry by immunohistochemistry. The nanoinjection method used in this study may be a useful method to study pathogens, like F psychrophilum, that can be vertically transmitted.
Scientific paper
Evaluation of gas chromatographic injection techniques for PBDE
During the last years there has been an increasing concern for polybrominated diphenyl ethers (PBDEs) as environmental pollutants. These compounds are used as additive flame retardants in a wide range of materials1 and have been found in sediments, sewage sludge and marine biota as well as in human blood and mothers milk2. The use of the fully brominated BDE-209 has been increasing while the use of the less brominated congeners is decreasing. Even though the BDE-209 is one of the most commonly used PBDE commercially only a few number of determinations have been reported, for instance in human blood3 and in air4, 5.
Gas chromatography is today the method of choice for the separation of PBDE due to high resolution and low detection limits using either the electron capture detector (ECD) or mass spectrometry (MS). Splitless is the most commonly used injection technique for GC separation of PBDE6. However, both the septum equipped temperature programmable injector (SPI) and the programmable temperature vaporising (PTV), injector as well as on-column has been successfully used6. Large volume injections (LVI) using either the PTV in solvent elimination mode or the loop type interface have also been used4, 7, 8. The injection of PBDE into the GC system is a critical and important part of the chromatographic analysis. Thus, a careful selection and optimization the injection techniques have to be performed in order to reduce the discrimination of theses compounds. In this paper we present an evaluation and optimisation of the most commonly used injection techniques for PBDE.
Technical report
Interlaboratory trial for validation of ISO/DIS 15586. Water quality – Determination of trace elements by atomic absorption spectrometry with graphite furnace.
atomic absorption
,
graphite furnace
,
interlaboratory trial
,
metals
,
standard
,
trace elements
Technical report
Emissioner av partiklar till luften i Stockholm.
eddy kovarians
,
ultrafina partiklar
Presentation abstract
Transformations of organic carbon in oxic and anoxic lake water – implications for pollutant bioavailability.
Presentation abstract
Biomarker studies of female perch (Perca fluviatilis) in a chronically polluted gradient through the Stockholm archipelago
Adult female perch (Perca fluviatilis) were investigated at several stations in the Stockholm archipelago in a gradient from Stockholm’s central waterways, through the archipelago to the open Baltic Sea. Various large-scale anthropogenic activities in and around the central part of the city have continuously contaminated especially the inner part of the approximately 80 km long gradient during the past 40 years.
The somatic condition factor, average yearly growth and percentage of sexually maturating females were recorded. Other physiological biomarkers, such as the somatic indices of visceral fat weight, spleen weight, liver weight and gonad weight (GSI) were also included in the study. The biochemical variables investigated were whole blood glucose and haemoglobin, as well as DNA adducts (nuclease P1 version of the 32P-postlabeling methodology), enzymatic activities of CYP1A (ethoxyresorufin O-deethylase), glutathione reductase, glutathione-S-transferase, catalase and glucose-6-phosphate dehydrogenase in the liver and acethylcholinesterase in muscle tissue. Finally, P450arom activity was analyzed in brain tissue.
Our results clearly suggest adverse effects on fish from the stations located within 20-30 km from Stockholm. The GSI and the ratios of sexually mature fish were decreased. The response of many of the biochemical biomarkers indicated an increase in pollution levels as the city is approached. Some of the biomarkers, such as EROD activity and DNA adducts showed, however, surprisingly low responses. Our interpretation of these results is that high chronic exposure has caused physiological and/or genetic resistance to normal biomarker response. In fact, supplementary laboratory studies indicate that this indeed could be the case. In one study, fish from the vicinity of Stockholm did not respond to pure benzo(a)pyrene exposure; in another study, control fish exposed to water/sediment from the area showed a greater response than the feral fish.
Scientific paper
Phthalate Esters: Physical-chemical properties and evaluative modelling.
Scientific paper
Inhibition of larval development of the marine copepod Acartia tonsa by four synthetic musk substances.
copepod
,
nitro musks
,
polycyclic musks
,
subchronic
,
toxicity