氯霉胺及其衍生物的质谱特征

利用气相色谱 -电子电离质谱 ( GC/EIMS)研究了手性 N ,N -二甲基氯霉胺及其两种衍生物的特征质谱。氯霉胺属于叔胺 (化合物 ) ,两种衍生物属于季铵盐 (化合物 , )。化合物 出现分子离子 M]+和准分子离子 M+H]+ ,化合物 、 只出现丢失碘和溴的碎片离子 M-I]+ 和 M-Br]+ 。数据显示 ,它们在高质量区都有共同的 m/z 2 41和 m/z 2 0 9;在低质量区具有相似的子离子群 m/z 88、m/z 77、m/z 5 8、m/z 45、m/z44等 ,尤其共同的基峰 m/z88成为检测该类化合物的质谱标志。质谱裂解机理分析表明 ,二甲氨基的存在是这些基本特征在分子结构上的内在原因

Mass Spectra Characterstics of Chiral Tertiary Amines and Quarternary Ammonium Salts Derivated From Chloamphenicol

The characteristic mass spectra of chiral tertiary amine (Compound Ⅰ) and two kinds of quarternary ammonium salts derivated (compound Ⅱ,Ⅲ) were determined by gas chromatography electron ionization mass spectrometry (GC/EIMS). The molecular ion (M +) and quasimolecular ion (M+H] +) was detected from compound Ⅰ, but only iodineloss ion (M I] +) and bromineloss ion (M Br] +) from compound Ⅱ, Ⅲ. The common fragementations m/z 241, m/z 209, m/z 88(base peak ion), m/z 77, m/z 58, m/z 45, m/z 44 and m/z 42 can be measured from compound Ⅰ, Ⅱ, Ⅲ. Their base peak ion m/z 88 can be used as symbol to go to the mass spectrometric analysis. The analysis of the fragemetation mechanism shows the privious cheracteristic mass spectra present because the molecular formula of chiral tertiary amine and quaternary ammonium salts derivated containe the dimethylamino.