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- Bewitterung (1)
- Brominated flame retardants (1)
- Mass spectrometry (1)
- Polyurethanes (1)
- Pressurized liquid extraction (1)
- Schadstoffaustrag (1)
- Sediment and fish samples (1)
- TDBP-TAZTO (1)
- TTBP-TAZ (1)
- Thermal degradation (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (3) (entfernen)
Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was
found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism.
In the present study, a novel and reliable analytical method was developed and validated for the simultaneous determination of 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TDBP-TAZTO) and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ) in environmental samples using high-performance liquid chromatography coupled to a tandem mass spectrometer.
Firstly, for optimization of the liquid chromatography separation, mobile phases, oven temperatures, modifiers, and buffers were varied. Afterwards, the extraction efficiency of sediment and fish samples was tested with different techniques (pressurized liquid, solid-liquid, ultrasound-assisted, and Soxhlet extraction). Additionally, cleanup using modified multilayer silica gel (sediment) and gel permeation chromatography as well as Florisil® columns (fish) with several solvent mixtures were performed. The best results were obtained with the pressurized liquid extraction (optimal conditions: extraction solvent 100% toluene, extraction time 20 min, cycles two, extraction temperature 100 °C, and flushing volume 60%) compared to other solvent extraction methods. On the basis of this optimized analytical procedure, the method was validated with satisfactory values of correlation coefficient (R2) between 0.998 and 0.999 for both matrices in the calibration range of 2.0–502.0 μg kg−1 for TDBP-TAZTO and 16.6–770.6 μg kg−1 for TTBP-TAZ in sediment samples as well as 4.8–303.5 μg kg−1 and 47.4–742.5 μg kg−1 in fish samples (bream), respectively.Mean recoveries (n=5) were calculated for both analytes with spiked matrices at one concentration level (100 μg kg−1) between 98 and 114% with intra-day relative standard deviations less than 11%. The inter-day precision (n = 15) was also acceptable for both compounds < 11%. It was found that the limit of detection and limit of quantification were in the range of 0.4–1.3 μg kg−1 for TDBP-TAZTO and 10–28 μg kg−1 for TTBP-TAZ in surface sediment samples and 7–25 μg kg−1 and 22–80 μg kg−1 in fish samples (bream), respectively. The results indicated that these analytical methods could provide reliable and efficient approaches for quantification of TDBP-TAZTO and TTBPTAZ in sediment and fish samples.
Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden.