نتایج جستجو برای: gc mass
تعداد نتایج: 504862 فیلتر نتایج به سال:
Gas chromatography/mass spectrometry (GC/MS) with negative ion chemical ionization permits detection of underivatized patulin in apple juice extracts while minimizing co-extractive responses. The technique has been used with a variety of capillary columns in quadrupole, ion trap, and magnetic sector GC/MS instruments to confirm presumptive findings of patulin in apple juice at concentrations ra...
Glyphosate is widely used in herbicides and is toxic to organism. Therefore accurate detection of glyphosate content is important for public health and food security. In this paper, methods such as gas chromatography (GC), high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC/MS), liquid chromatography-mass spectrometry (LC/MS), ion chromatography (IC), capilla...
The 2-, 3-, and 4-methoxyamphetamines and methoxymethamphetamines were prepared and analyzed by GC-MS. Regioisomerism at the aromatic ring in these compounds possess similar analytical properties. They show similar gas chromatographic retention properties on a column with phenylmethylsilicone (HP-5) stationary phase. The mass spectra for the underivatized amines are similar and fail to provide ...
Thyrotoxicosis is frequently associated with increased bone turnover and decreased bone mass. To investigate the role of thyroid hormone receptor-beta (TR beta) in mediating the osteopenic effects of triiodothyronine (T3), female adult rats were treated daily (64 days) with GC-1 (1.5 microg/100 g body wt), a TR beta-selective thyromimetic compound. Bone mass was studied by dual-energy X-ray abs...
Ifosfamtde, an oxazaphosphonne, IS thermally stable dunng elutton m gas chromatography (GC) at temperatures above 2OO”C, m contrast to tts structural Isomer cyclophosphamrde. Both 2.65~gm and 0.32~pm OV-1 columns were effrctent for GC of tfosfamtde wrthout derivatmation. Mass spectrometry (MS), showed that Intact tfosfamrde was eluted without interference from naturally occurring metabohtes in ...
A new data analysis software system (Ion Fingerprint DetectionTM) has been developed to provide fast mass spectral data analysis. Methods have been developed that can provide screening to quantitative gas chromatography/mass spectrometry (GC/MS) data in 30 s to minutes. Compound selectivity is provided through a unique set of algorithms rather than GC separation. The data quality produced for v...
Effective deoxygenation in catalytic fast pyrolysis (CFP) is crucial for bio-oil stabilization and its successful commercialization. Herein, we utilize a new analytical platform that couples gas chromatography (GC) to dopant-assisted atmospheric pressure chemical ionization (dAPCI) time-of-flight mass spectrometry (TOF MS) to evaluate catalytic deoxygenation of cellulose pyrolysis. Soft ionizat...
A method for the analysis of glufosinate ammonium (GLUF) and its metabolite 3-methylphosphinicopropionic acid (MPPA) in human serum by gas chromatography-mass spectrometry (GC-MS) was developed. Employing a mixed-mode cartridge with both anion exchange action and weak nonpolar interaction, we extracted GLUF and MPPA from the serum and carried out GC-MS analysis of their tert-butyldimethylsilyl ...
Concentrations of amino acids in a human plasma pool were determined using four independent quantification methods. Orthogonal separation schemes (LC, GC, or GC x GC) and detection systems (triple quadrupole or time-of-flight mass spectrometry) are shown to demonstrate excellent consistency among platforms for quantifying 18 amino acids in NIST Standard Reference Material (SRM) 1950 Metabolites...
آلکیل دار کردن فریدل-کرافتس یک واکنش مهم برای اتصال زنجیرهای آلکیل به حلقه های آروماتیک است. آلکیل دار کردن عموما بااستفاده از آلکیل هالیدها در حضور کاتالیزگر اسیدلوئیس مانند alcl3 و یا با استفاده از الکل ها در حضور کاتالیزگر اسید برونستد، عموماh2so4 ، انجام می شود. کاتالیزگرهای همگن به آسانی بعد از واکنش جدا نمی شوند و مقادیرزیادی فاضلاب اسیدی تولید می کنند. امروزه، تحقیقات وسیعی برای جایگزین ...
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