Stage 2/Structure Idenification (NMR , LCMS) (8) 썸네일형 리스트형 Mass spectrometry introduction (GC/MS) GC/MS (EI 위주로…) 1. 검출기 선택시 고려 사항 가. Selectivity : 분석 대상 화합물에 적합한지? 나. Sensitivity : 분석 대상 화합물에 적합한 감도 (S/N ratio, MDL) 다. Linearity : 정량을 위한 검량선 작성시 직선성이 충분한가? (Linear range, overload) - 직선성 = 최대검출농도 / 최소검출농도 *** MDL 방법검출한계(MDL, method detection limit)란 시료와 비슷한 매질 중에서 시험분석 대상을 검출할 수 있는 최소한의 농도로서, 제시된 정량한계 부근의 농도를 포함하도록 준비한 n 개의 시료를 반복 측정하여 얻은 결과의 표준편차(s)에 99 % 신뢰도에서의 t-분포값을 곱한 것이다. 산출된 방법검출한계는 제.. Lactone In chemistry, a lactone is a cyclic ester[1] which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule. It is characterized by a closed ring consisting of two or more carbon atoms and a single oxygen atom, with a ketone group =O in one of the carbons adjacent to the other oxygen.Nomenclature Lactone nomenclature: α-acetolactone, .. Carbonyl In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, e.g. nickel carbonyl); in this situation, carbon is triple-bonded to oxygen: C≡O. Note that the most specific labels are usually employed. For examp.. HMBC ( Heteronuclear Multiple Bond Correlation ) 2D HMBC (Heteronuclear Multiple Bond Correlation) experiment correlates chemical shifts of two types of nuclei separated from each other with two or more chemical bonds. This is an improvement of the old COLOC experiment. For example 1H,13C-HMBC correlates chemical shifts of protons with carbons separated with two or three bonds, in some cases even with the more distant ones. The zero and double.. DEPT NMR DEPT is an acronym for Distortionless Enhancement by Polarization Transfer. This experiment allows to determine multiplicity of carbon atom substitution with hydrogens. For this purpose, three experiments need to be recorded, where pulse with φ3 has flip angle of 45o (a), 90o (b), and 135o (c). Signs of signals in these experiments will reveal the substitution of carbon atoms: in a (DEPT-45) all.. Advanced 2D NMR experiment [] TOCSY TOCSY (Total Correlation Spectroscopy) creates correlations between all protons within a given spin system, not just between geminal or vicinal protons as in COSY. Correlations are seen between distant protons as long as there are couplings between every intervening proton. This is extremely useful for identifying protons on sugar rings or amino acids: All protons on a given sugar rin.. NMR operation 일시 : 2010 5 26 일 장소 : 서울대 기초과학공동기기원 2일간의 이론교육을 끝내고 금일 실습기회를 가졌습니다. 친절한 조교님 덕에 사고(?) 없이 무사히 끝냈네요ㅋ [1] Sample 0.2mmol 농도의 Sample 준비 ( 시료를 녹인 검액은 tube bottom에서부터 상부 3Cm정도 이상으로 담아준다,shimming 일정하게 하기위함) [2] Operation 1. Computer On 2. Log-in , PW 입력 3. TOPSCAN 실행 4. lock signal window 실행 ( 창이 뜨지 않는 경우 상부 입력바의 버튼을 눌러준다) 5. File-New 6. Name ( folder name ) , EXPNO ( sub-folder , sample갯수로 지정하면 좋다 ) 입력 .. NMR solvent " chemical shift " 실험도 점점 막바지를 향해 가지만 아직도 갈 길은 멀게만 느껴진다... 최종 과정인 구조결정.. 잘 할수 있을까? --; 까다롭지만 마치 퍼즐을 푸는 것 같은 재미도 있다. 출처 : http://www.isotope.com/cil/products/images/nmrchart.pdf http://www.isotope.com/uploads/File/NMRUNpriced-proof.pdf 이전 1 다음
