نتایج جستجو برای: gc mass
تعداد نتایج: 504862 فیلتر نتایج به سال:
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...
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...
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...
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 ...
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...
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...
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 ...
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...
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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