نتایج جستجو برای: gc mass

تعداد نتایج: 504862  

Journal: :Drug testing and analysis 2016
Adam T Cawley Karen Blakey Christopher C Waller Malcolm D McLeod Sue Boyd Alison Heather Kristine C McGrath David J Handelsman Anthony C Willis

In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid-related compounds. Subsequent gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α- and 3β- isomers of the novel compound; 3-chloro-17α-methyl-5α-androstan-17β-ol. Synthesis of authentic reference materials followed by comp...

2004
Daniel M. White D. Sarah Garland Lothar Beyer Kenji Yoshikawa

This paper describes four recent applications of analytical pyrolysis in environmental science and engineering. In all applications, samples were analyzed in order to provide information about the origin of organic matter or changes to an organic matrix. In the first application, pyrolysis-gas chromatography/mass spectrometry (GC/MS) and pyrolysis-GC/flame ionization detection (FID) were used t...

2014
Yong-Gang Xia Bing-You Yang Jun Liang Qi Yang Di Wang Hai-Xue Kuang

This paper describes a simple, rapid, and effective quality assessment method for Fructus Schisandrae by gas chromatography-mass spectrum (GC-MS). The method was established by using specific lignan fingerprint profiles and quantitation of characteristic compounds in this herbal medicine. The GC-MS fingerprints of 15 batches of Schisandra samples from different regions of China showed similar l...

Journal: :Journal of nutritional science and vitaminology 2006
Jun Iwamoto Azusa Seki Tsuyoshi Takeda Yoshihiro Sato Harumoto Yamada Chwan-Li Shen James K Yeh

OBJECTIVES To compared the effects of risedronate (Ris) and calcitriol (Cal) on cancellous bone in rats with glucocorticoid (GC)-induced osteopenia. MATERIALS AND METHODS Thirty female Sprague-Dawley rats, 4 mo of age, were randomly divided by the stratified weight method into three groups of 10 rats each according to the following treatment schedule: 8-wk GC administration with 4-wk vehicle ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - پژوهشکده علوم 1393

هدف اصلی در این مطالعه بررسی اثرغلظت های مختلف هورمون های iaa و naa و3 ga براسانس گیاه جعفری می باشد . دراین روش ابتدا بااستفاده از مطالعات کتابخانه ای از کارها و هورمونتراپی های مشابه اطلاع پیدا کردیم ،سپس بذراصلاح شده گیاه راتهیه کردیم وتحت مراقبت بذرها کاشته شدند . پس ازکامل شدن دوره رشدگیاه اقدام به هورمونتراپی به وسیله هورمون های فوق کردیم . گیاهان جمع آوری شده ودر سایه ودور از نورخورشید و...

2014
Elena Stashenko Jairo René Martínez

Gas chromatography (GC) is a widely applied technique in many branches of science and technology. For over half a century, GC has played a fundamental role in determining how many components and in what proportion they exist in a mixture. However, the ability to establish the nature and chemical structure of these separated and quantified compounds is ambiguous and reduced, and requires a spect...

Journal: :Environmental science & technology 2009
Eunha Hoh Steven J Lehotay Katerina Mastovska Helen L Ngo Walter Vetter Kristin C Pangallo Christopher M Reddy

Most analytical methods for persistent organic pollutants (POPs) focus on individual groups of targeted analytes. Therefore, analysis of multiple classes of POPs typically entails several sample preparations, fractionations, and injections, whereas other chemicals of possible interest are neglected or lost. To analyze a wider scope of organic contaminants in fish oil, we developed an approach t...

استفاده از گیاهان آبزی و جلبک‌ها به واسطه داشتن ترکیب‌های مختلف در پیشگیری و درمان بیماری‌ها از سالها پیش رایج بوده است. جلبک قرمز Gracilaria salicornia با داشتن ترکیبهایی با ساختار شیمیایی خاص میتواند اکسیژن تکی را دفع و جاذب رادیکالها باشند. هدف از این مطالعه بررسی اثر کشندگی عصاره و فراکشن‌های این جلبک بر رده سلولی سرطان پستان(MCF7) و نرمال فیبروبلاست ریه جنین (MRC5)  با استفاده از ...

Journal: :Anticancer research 2011
Yasuyoshi Miyata Yuji Sagara Tomohiro Matsuo Kojiro Ohba Hajime Takahashi Hideki Sakai Hiroshi Kanetake

Urachal cancer is a rare malignancy and the standard treatment is surgical resection. The prognosis of recurrent and metastatic urachal cancer is extremely poor because there is no established chemotherapy regimen. Here, the response of one patient with recurrent urachal cancer to combination chemotherapy of gemcitabine (GEM) and cisplatin (CDDP) (GC) is described. And the chemo- and radiothera...

2012
Shuifu Li Shouzhi Hu Jian Cao Ming Wu Dongmei Zhang

Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from t...

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