Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Development of GC-HRMS procedures for determination of naturally occuring polar compounds in various environmental applications 
Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The overall objectives of this dissertation were to gain further understanding of the two following environmentally significant issues: (i) Determination of natural steroid hormones in blood plasma from perch (Perca fluviatilis) during a reproductive cycle and to evaluate the possibility of using the steroid composition as a biomarker for early signs of endocrine disruptive effects. (ii) Determination of dissolved free amino acids in size resolved airborne particles collected over the Arctic pack ice area (>80°N) in summer and to study their overall relationship with the ocean surface microlayer as a potential source.

 This was made possible by the development of two separate gas chromatographic–high resolution mass spectrometry methods. To enable separation with gas chromatography both steroids and amino acids had to be chemically modified to increase their volatility. The small sample volumes available and low concentrations of analytes required a multi-step clean-up procedure to enable determination.

 The results showed that the circulating levels of steroids in perch varied over the year and that the levels of some androgens were lower in female perch exposed to leachate from a refuse dump compare to unexposed perch, which may explain the decline in fertility observed for the former group. This also indicated that the steroid composition in the blood plasma may function as a sensitive biomarker.

 The levels of dissolved free amino acids were enriched in the submicrometer aerosol, peaking in sizes around 100nm aerodynamic diameter. These findings do support a previous assumption that the most likely source for these particles is the surface microlayer of the open water between the ice floes. The most likely exchange mechanism of biogenic matter between ocean and atmosphere is the bursting of bubbles at the surface of the leads. This mechanism would provide a very important and poorly understood link between cloud radiative properties and marine biochemistry in the summer high Arctic (>80°N) through the production of cloud condensation nuclei.

Place, publisher, year, edition, pages
Stockholm: Department of Applied Environmental Science (ITM), Stockholm University , 2009. , 57 p.
Keyword [en]
GC-HRMS, steroid hormones, amino acids, perch, size-resolved aerosol, Arctic
National Category
Natural Sciences
Research subject
Applied Environmental Science
Identifiers
URN: urn:nbn:se:su:diva-29283ISBN: 978-91-7155-907-4 (print)OAI: oai:DiVA.org:su-29283DiVA: diva2:232197
Public defence
2009-09-25, De Geer salen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Accepted. Paper 4: In progress. Paper 5: In progress.Available from: 2009-09-03 Created: 2009-08-20 Last updated: 2009-09-01Bibliographically approved
List of papers
1. Simultaneous determination of several natural steroids in blood plasma from perch (Perca fluviatilis) by GC-HRMS
Open this publication in new window or tab >>Simultaneous determination of several natural steroids in blood plasma from perch (Perca fluviatilis) by GC-HRMS
(English)Manuscript (preprint) (Other academic)
Abstract [en]

A gas chromatography–high resolution mass spectrometry (GC-HRMS) procedure for the simultaneous determination of 18 endogenous steroid hormones in blood plasma from teleost fish has been developed. Proteins were removed by precipitation in methanol and lipids were removed by a liquid-liquid extraction. The protein and lipid free extract was further purified by using two successive solid phase extraction (SPE) methods (C18 and NH2). The isolated steroid hormones were silylated with a mixture of N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA): iodotrimethylsilane (TMSI ):dithioerythritol (DTE) prior to determination with GC-HRMS working in selective ion recording mode. A volume of 200 mL blood plasma was sufficient for accurate determination of the steroid hormone levels, which enabled determination in individual fish. The detection limits ranged from 0.0003 to 0.2 ng/g blood plasma from perch (Perca fluviatilis), approximately 10 to 100 times lower then previously reported in this field. The recoveries for the entire procedure were in the range 58 to 150% with a variation, expressed as standard deviation (SD), below 10% with some exceptions. Despite the multi-step clean-up procedure, the intra-assay coefficient of variation, i.e. the within-day variation, for most steroid hormones was well below 14%. Finally, the procedure has been successfully applied to the determination of steroid hormones in blood plasma from female perch caught in two Swedish lakes.

Keyword
endocrine disruption, testosterone, GC-HRMS, silylation
National Category
Environmental Sciences
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-29472 (URN)
Available from: 2009-09-01 Created: 2009-09-01 Last updated: 2010-01-14Bibliographically approved
2. Gonad development and plasma steroid profiles by HRGC/HRMS during one reproductive cycle in reference and leachate-exposed female perch (Perca fluviatilis)
Open this publication in new window or tab >>Gonad development and plasma steroid profiles by HRGC/HRMS during one reproductive cycle in reference and leachate-exposed female perch (Perca fluviatilis)
Show others...
2004 (English)In: Toxicology and Applied Pharmacology, ISSN 0041-008X, E-ISSN 1096-0333, Vol. 195, no 2, 247-261 p.Article in journal (Refereed) Published
Abstract [en]

Endocrine processes were studied in reference female perch (Perca fluviatilis) from Lake Djursjön and in leachate-exposed females from Lake Molnbyggen during one reproductive cycle. A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) technique enabled the analysis of circulating sex steroids [progesterone (P), 17α-hydroxyprogesterone (17α-OHP), androstenedione (A), testosterone (T), estrone (E1), and 17β-estradiol (E2)], the maturation-inducing hormone (MIH) 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-P), and glucocorticoids [11-deoxycortisol (11-DC) and cortisol]. Body and organ measurements, ratio of sexually mature (SM) females, and frequencies of body lesions, were also recorded. High frequencies of body lesions and a low ratio of SM females were generally found in Molnbyggen. These females also had lower gonadosomatic index (GSI) and liver-somatic index (LSI) in the early stages of vitellogenesis, indicating either a delayed onset of oogenesis or an impaired vitellogenesis. Non-reproducing females from both lakes showed a similar LSI cycle as SM females. Increasing T and A levels in SM females from Djursjön coincided with the GSI peak at the time of spawning. These two androgens were on several occasions lower in SM females from Molnbyggen, possibly the result of a disrupted 17,20-lyase activity of the P450 17α enzyme because only minor effects were observed on circulating P and 17α-OHP levels. E2 and E1 levels increased during vitellogenesis in females from both lakes, with E1 levels more closely resembling the peaks of A and GSI. Peak levels of 17α,20β-P at the time of spawning confirmed its function as the MIH in perch, while the simultaneous peak of 11-DC suggests that it also may be involved in final maturation of the oocytes.

Keyword
Reproductive cycle; Gonad development; Sexual immaturity; Steroid profiles; Endocrine disruption; HRGC/HRMS; Refuse dump leachate; Perch (Perca fluviatilis)
National Category
Environmental Sciences
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-29475 (URN)10.1016/j.taap.2003.11.017 (DOI)
Available from: 2009-09-01 Created: 2009-09-01 Last updated: 2017-12-13Bibliographically approved
3. Reproductive status in female perch (Perca fluviatilis) outside a sewage treatment plant processing leachate from a refuse dump
Open this publication in new window or tab >>Reproductive status in female perch (Perca fluviatilis) outside a sewage treatment plant processing leachate from a refuse dump
Show others...
2005 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 340, no 1-3, 97-112 p.Article in journal (Refereed) Published
Abstract [en]

Reproductive failure and endocrine disruption in female perch (Perca fluviatilis) and female brook trout (Salvelinus fontinalis), naturally exposed to toxic leachate from a municipal refuse dump, has raised concerns about the reproductive status in female fish outside the sewage treatment plant (STP), which now treats the same leachate. Female perch from the receiving water, Lake Siljan, were therefore sampled in a gradient from the STP in Fornby and Österviken and compared with reference females from Isunda or Sollerön. A high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) technique enabled the analysis of circulating steroids in blood plasma: the sex steroids progesterone (P), 17α-hydroxyprogesterone (17α-OHP), androstenedione (A), testosterone (T), estrone (E1), and 17β-oestradiol (E2), the maturation-inducing hormone (MIH) 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-P), and the glucocorticoids 11-deoxycortisol (11-DC) and cortisol (C). Body and organ measurements, ratio of sexually mature (SM) females, and frequencies of body lesions, were also recorded. The percentages of SM females found in Fornby on Oct 23 (83.8%) and in Österviken on May 14 (54.0%) were lower compared with Isunda (100%). The lack of differences in gonadosomatic index (GSI) and liver-somatic index (LSI) indicated a normal vitellogenesis in SM females from Fornby and Österviken. No differences in circulating levels of steroids were observed between the sites, except at the time of spawning, when elevated P and 17α-OHP levels in females from Österviken indicated a steroidogenic shift from the synthesis of sex steroids towards the production of the MIH 17α,20β-P. The significant peak-levels of both 17α,20β-P and 11-DC in female perch from Österviken at the same time suggest that both are involved in controlling final oocyte maturation in perch. The elevated levels of androgens (A and T) in females caught on the same occasion in Fornby implied that these females were at an earlier stage of oocyte maturation, prior to the steroidogenic shift towards MIH-production. This study confirms the results of an earlier study revealing low numbers of SM female perch outside the STP in Fornby. The lack of associated effects on organ indexes and circulating levels of steroids does not indicate exposure to endocrine disrupting substances (EDSs) from the treated sewage. The consistently high numbers of SM females in the northern part of Siljan suggest, however, that natural factors are not responsible for the reproductive failures in the southern part of the lake.

Keyword
Reproductive failure; Steroid profiles; HRGC/HRMS; Refuse dump leachate; Sewage treatment plant; Perch (Perca fluviatilis)
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-29476 (URN)10.1016/j.scitotenv.2004.08.010 (DOI)
Available from: 2009-09-01 Created: 2009-09-01 Last updated: 2017-12-13Bibliographically approved
4. Determination of amino acids in size-segregated airborne particles using GC-HRMS
Open this publication in new window or tab >>Determination of amino acids in size-segregated airborne particles using GC-HRMS
(English)Manuscript (preprint) (Other academic)
Abstract [en]

A gas chromatography–high resolution mass spectrometry methodology for the simultaneous determination of 14 amino acids in size-segregated airborne particles has been developed. A five-stage high-volume low-pressure Berner Cascade Impactor was used to collect the particles on Tedlar® substrates and Millipore Fluoropore filters. The substrates and filters were extracted with methanol and the extract was treated with a cation exchanger to concentrate the amino acids. N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide (MTBSTFA)+1% t-butyldimethyl-chlorosilane (TBDMCS) and acetonitril were added to silylate the amino acids before determination with gas chromatography-high resolution mass spectrometry working in selective ion recording mode. The detection limits (S/N ³ 3) for most of the amino acids ranged from 1 to 3 pg amino acid injected. The recoveries for the entire procedure were in the range of 61 to 104% and the variations obtained were approximately 10% for all amino acids. The procedure has been applied to ambient atmospheric samples collected during the Arctic Ocean Expedition (AOE-2001) from July through August 2001, 71 to 90°N.

National Category
Environmental Sciences
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-29473 (URN)
Available from: 2009-09-01 Created: 2009-09-01 Last updated: 2010-01-14Bibliographically approved
5. Free amino acids in aerosol samples collected over the central Arctic Ocean in summer 
Open this publication in new window or tab >>Free amino acids in aerosol samples collected over the central Arctic Ocean in summer 
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Size-resolved airborne particle samples collected over the central Arctic Ocean in summer, during the Arctic Ocean expedition (AOE)-2001, have with regard to dissolved free amino acids (DFAAs) been analysed. Serine, alanine, aspartic acid followed by glutamatic acid was the dominating amino acids in the DFAA fraction. The high concentrations of serine found in all blanks must be taken into consider discussing its contribution. The total concentration of DFAAs in the bulk aerosols, with serine excluded ranged from 13-89 pmol/m3, which agree well with previous less size-resolved data reported for remote areas. The DFAA fraction was shown to explain <0.7% of the total particle mass collected on the substrate. The size distribution of the DFAAs showed enrichment towards the submicron mode with a factor of 2-3 compare to the coarse mode. As the DFAAs were found in sizes corresponding to either film or jet drops, or to both, the surface micro layer was suggested to be their source. A comparison of the reported DFAA composition with amino acid data obtained for simultaneously collected micro layer samples, showed no clear relation. Ongoing oxidation of proteins and peptides on the sampling substrate combined with the considerable variation of the amino acid composition in the microlayer over time and sampling site may explain the obtained differences.

National Category
Meteorology and Atmospheric Sciences
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-29474 (URN)
Available from: 2009-09-01 Created: 2009-09-01 Last updated: 2010-01-14Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Widell, Bodil
By organisation
Department of Applied Environmental Science (ITM)
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 404 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf