List of abbreviations and symbols .............................. IV
List of publications ............................................ V
Summary ........................................................ VI
Zusammenfassung ................................................. X
1 Motivations and Objectives ................................... 1
2 Background ................................................... 3
2.1 Properties and occurrence of uranium .................... 3
2.2 Aqueous chemistry of uranium ............................ 4
2.2.1 Chemical speciation in solutions ................. 5
2.2.2 U(VI) species with inorganic ligands ............. 6
2.2.3 U(VI) species with organic ligands ............... 8
2.3 Uranium in natural waters .............................. 10
2.3.1 Guidelines limit for drinking water ............. 10
2.4 Human exposure ......................................... 11
2.5 Health effects of uranium .............................. 13
3 Fluorescence Spectroscopy of Uranium(VI) .................... 15
3.1 Principle of fluorescence .............................. 15
3.2 Fluorescence properties of uranium ..................... 20
3.2.1 U(VI) speciation by laser fluorescence
spectroscopy .................................... 22
3.3 Chemical quenching of uranyl luminescence .............. 25
3.4 Determination of the complex stability constant from
spectroscopic data ..................................... 27
3.5 Fluorescence properties at low temperatures ............ 28
4 Results and Discussion ...................................... 30
4.1 Investigation of U binding forms in environmentally
relevant waters ........................................ 30
4.1.1 U(VI) speciation in selected German mineral
waters .......................................... 30
4.1.1.1 Water samples and analytical data ...... 30
4.1.1.2 Speciation modeling of the mineral
waters ................................. 32
4.1.1.3 Luminescence characteristics of
uranium in mineral waters .............. 36
4.1.1.4 Uranium speciation in (STILL) water .... 37
4.1.1.5 Uranium speciation in (CLASSIC) water .. 39
4.1.2 U(VI) speciation in groundwater - Pofadder
case study ...................................... 42
4.1.2.1 Sampling and water parameters .......... 42
4.1.2.2 Speciation modeling of Pofadder
groundwater ............................ 42
4.1.2.3 Luminescence data of uranium in
Pofadder groundwater ................... 44
4.1.3 U(VI) speciation in acid drainage waters ........ 44
4.1.3.1 Samples locations and analytical data .. 44
4.1.3.2 Thermodynamic modeling of acid
drainage waters ........................ 45
4.1.3.3 Luminescence data of U(VI) in acid
drainage waters ........................ 46
4.1.4 Concluding remarks .............................. 47
4.2 Interaction of uranium(VI) with bioligands present in
human biological fluids: The case study of urea and
uric acid .............................................. 49
4.2.1 Relevance of the study .......................... 49
4.2.2 Bioligands under investigation .................. 49
4.2.3 Interaction of uranium(VI) with uric acid ....... 51
4.2.4 Interaction of uranium(VI) with urea ............ 55
4.2.4.1 Urea set 10-5 to 10-4 M ................. 55
4.2.4.2 Urea set 0.01 to 0.3 M ................. 57
4.2.5 U(VI) speciation calculations in human urine .... 60
4.2.6 Concluding remarks .............................. 63
4.3 Uranium(VT) binding forms in some human body fluids:
spectroscopy and modeling investigation ................ 65
4.3.1 Significance and aim of the study ............... 65
4.3.2 Specimens' collection/preparation ............... 66
4.3.3 Analytical data and uranium spiking
experiments ..................................... 66
4.3.4 U(VI) speciation in body fluids - modeling ...... 68
4.3.4.1 Speciation modeling of U(VI) in
saliva ................................. 68
4.3.4.2 Speciation modeling of U(VI) in sweat .. 70
4.3.4.3 Speciation modeling of U(VI) in urine .. 72
4.3.5 U(VI) speciation in body fluids - TRLFS ......... 75
4.3.5.1 Luminescence characteristics of U(VI)
in saliva .............................. 75
4.3.5.2 Luminescence characteristics of U(VI)
in sweat ............................... 79
4.3.5.3 Luminescence characteristics of U(VI)
in urine ............................... 80
4.3.6 Concluding remarks .............................. 83
4.4 Conclusion and Outlook ................................. 85
5 Experimental Details ........................................ 87
5.1 Chemicals and solutions ................................ 87
5.1.1 Uranium(VI) stock solution ...................... 87
5.1.2 Complexation experiments of U(VI) with urea
and uric acid ................................... 87
5.1.3 Preparation of artificial body fluids ........... 88
5.2 Methods ................................................ 89
5.2.1 SPECFIT ......................................... 89
5.2.2 Thermodynamic modeling .......................... 89
5.2.3 Elemental analysis .............................. 90
5.2.4 Determination of carbon ......................... 90
5.2.5 Measurement of pH and EC values ................. 90
5.3 Spectroscopy technique - TRLFS ......................... 90
5.3.1 TRLFS measurements of U(VI) complexes with
urea and uric acid .............................. 90
5.3.2 Cryo-TRLFS measurements for natural waters and
body fluids ..................................... 91
5.3.3 Sample preparation for cryo-TRLFS measurement ... 92
5.4 Data on mineral water samples .......................... 93
6 References .................................................. 95
Annexes .................................................... 110
Eidesstattliche Erklärung ................................... XV
| 
