نتایج جستجو برای: mass spectrometry gc ms also

تعداد نتایج: 2862344  

2016
Ronda F. Greaves

Since the latter half of the 20th century mass spectrometry (MS) applications, associated with gas chromatography (GC) separation (i.e. GC-MS), have been the “gold standard” in specialised clinical laboratories for the quantitation of drugs, organic acids and steroids [1]. This status quo remained unchallenged until just over a decade ago when liquid chromatography coupled with tandem mass spec...

2013
Sandra E. Rodriguez-Cruz

The analysis and characterization of 12 “designer” tryptamines by electrospray ionization mass spectrometry (ESI-MS) are presented. Molecular weights were confirmed based on the experimental observation of protonated and deprotonated pseudo-molecular ions in the positive and negative ion modes, respectively. Standard tandem mass spectrometry (MS) experiments were also performed, and the results...

2017
Torben Breindahl Andreas Kimergård Mette Findal Andreasen Daniel Sejer Pedersen

Among the new psychoactive substances (NPS) that have recently emerged on the market, many of the new synthetic opioids have shown to be particularly harmful. A new synthetic analogue of fentanyl, N-phenyl-N-[1-(2-phenethyl)piperidin-4-yl]prop-2-enamide (acrylfentanyl), was identified in powder from a seized capsule found at a forensic psychiatric ward in Denmark. Gas chromatography with mass s...

Journal: :Journal of chromatography. A 2016
Sebastian Naeher Sabine K Lengger Kliti Grice

Maleimides (1H-Pyrrole-2,5-diones) are monopyrrolic pigment derivatives with specific alkyl side chains that can be directly linked to their tetrapyrrole precursors, most notably chlorophylls and bacteriochlorophylls. These compounds can be used as palaeoenvironmental indicators such as algal productivity and redox conditions in ancient and modern aquatic systems. Here, we present a new method ...

2013
Seongho Kim Xiang Zhang

Peak alignment is a critical procedure in mass spectrometry-based biomarker discovery in metabolomics. One of peak alignment approaches to comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-MS) data is peak matching-based alignment. A key to the peak matching-based alignment is the calculation of mass spectral similarity scores. Various mass spectral similarity measures h...

Journal: :Journal of chromatography. A 2005
Shukui Zhu Xin Lu Li Dong Jun Xing Xueli Su Hongwei Kong Guowang Xu Caiying Wu

A quantitative analysis of the individual compounds in tobacco essential oils is performed by comprehensive two-dimensional gas chromatography (GC x GC) combined with flame ionization detector (FID). A time-of-flight mass spectrometer (TOF/MS) was coupled to GC x GC for the identification of the resolved peaks. The response of a flame ionization detector to different compound classes was calibr...

2017
Yunshuang Fan Yamei Li Yuanyuan Wu Lixin Li Yuming Wang Yubo Li

Simiao Wan (SMW), an important multiherbal formula used in traditional Chinese medicine, is extensively used to treat rheumatoid arthritis. However, the knowledge of the bioactive components of SMW remains unclear. Thus, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were used to analyze the chemical constituents of volatile and nonvolatile extr...

2004
Scott D. Hanton

From a traditional perspective, mass spectrometry and polymer analysis appear to be incompatible. Mass spectrometry requires gas-phase ions for a successful analysis and polymers are composed of large, often entangled macromolecules that are not readily converted to gas-phase species. Despite these natural difficulties, mass spectrometry techniques have been developed to characterize the chemic...

2012
Bei Liu You-Ming Li Shu-Bin Wu Yan-Heng Li Shan-Shan Deng Zheng-Lin Xia

Pyrolysis characteristics and mechanism of tobacco stem were studied by pyrolysis coupled with gas chromatography/mass spectrometry (PyGC/MS), thermogravimetric analyzer coupled with Fourier transform infrared spectrometry, and mass spectrometry (TG-FTIR and TG-MS) techniques. The composition of evolved volatiles from fast pyrolysis of tobacco stem was determined by Py-GC/MS analysis, and the e...

Journal: :Clinical chemistry and laboratory medicine 2013
Jennifer L Shea

Abstract Levamisole is an anthelminthic that was first used as a de-worming agent in humans and animals. It has also been used to treat inflammatory conditions as well as certain types of cancer. Levamisole was discontinued for human use in the early 21st century due to toxic side effects including agranulocytosis and vasculitis. Recently, levamisole was discovered as a cocaine adulterant after...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید