scholarly journals Low Temperature Decomposition of Polystyrene

2020 ◽  
Vol 10 (15) ◽  
pp. 5100
Author(s):  
Hideki Kimukai ◽  
Yoichi Kodera ◽  
Koushirou Koizumi ◽  
Masaki Okada ◽  
Kazunori Yamada ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Decomposition ◽  
Quantitative Analysis ◽  
Main Product ◽  
Basic Structure ◽  
Industrial Area ◽  
Decomposition Kinetics ◽  
Natural Environments ◽  
Selected Ion Monitoring ◽  
Temperature Decomposition

Styrene oligomers (SOs), of styrene (styrene monomer, SM), 1,3-diphenylpropane (styrene dimer, SD1), 2,4-diphenyl-1-butene (styrene dimer, SD2) and 2,4,6-triphenyl-1-hexene (styrene trimer, ST), had been detected in the natural environments far from industrial area. To confirm SOs formation through thermal decomposition of polystyrene (PS) wastes in the nature, purified polystyrene (SO-free PS) has been shown to decompose at 30 to 150 °C. The SO ratio of SM:SD:ST was about 1:1:5 with ST as the main product. Mass spectrometry with selected ion monitoring was used for the quantitative analysis of the trace amounts of SOs. The rate of PS decomposition was obtained as k(year−1)=5.177 exp(−5029/T(K)) based on the amount of ST. Decomposition kinetics indicated that not only does drifting lump PS break up into micro/nano pieces in the ocean, but that it also subsequently undergoes degradation into basic structure units SO. According to the simulation at 30 °C, the amounts of SOs in the ocean will be over 400 MT in 2050.

scholarly journals Determination of dimethoxyphenethylamine derivatives in urine by deuterium labeled internal standards

2008 ◽  
Vol 73 (12) ◽  
pp. 1223-1233 ◽  
Author(s):  
Ya-Zhu Xu ◽  
Huei-Ru Lin ◽  
Ahai-Chang Lua ◽  
Chinpiao Chen
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Forensic Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Internal Standards ◽  
Chromatography Mass Spectrometry ◽  
Accuracy And Precision

The use of gas chromatography-mass spectrometry (GC-MS) in forensic analysis is increasing. To exploit fully the capabilities of MS, labeled standards, that can be used to improve the performance of the quantitative analysis, and to increase accuracy and precision, are required. A series of deuterated internal standards, corresponding to the 2C-series of phenethylamine derivatives, including 4-bromo-2,5-dimethoxyphenethylamine-d6 (2C-B), 4-chloro- 2,5-dimethoxyphenethylamine-d6 (2C-C), 4-iodo-2,5-dimethoxy-phenethylamine-d6 (2C-I), 4-ethylthio-2,5-dimethoxy-phenethylamine-d6 (2C-T-2) and 2,5-dimethoxy-4-n-propylthiophenethylamine-d6 (2C-T-7), were synthesized. These deuterated compounds were used to analyze for the corresponding unlabeled compounds in urine. The analysis was performed using GC-MS, with the selected ion monitoring (SIM) technique, whereby good results were achieved.

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