共查询到19条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
通过反相液相色谱(RPLC)与电喷雾电离质谱(ESI-MS)的联用技术,对镉诱导金属硫蛋白标准物质MT-1和MT-2的结构进行表征分析。采用Vydac C8 反相色谱柱(250 mm×2.1 mm i.d., 5 μm, 30 nm),流动相A为pH 6.0的5 mmol/L乙酸铵水溶液,流动相B为pH 6.0的5 mmol/L乙酸铵的甲醇-水(体积比为1∶1)溶液,流动相流速为0.20 mL/min,在40 min内流动相B的体积分数从10%增加到37.5%进行梯度洗脱。分别用紫外(UV)和ESI-M 相似文献
11.
12.
The mass spectra of twenty-nine sydnones were measured by using NII3 as a reagent gas. The [M + H + NH3]+ ions are the base peaks for the entire series. Very few fragment ions were observed except for the derivatives of 4-hydroxymethylenesydnones (XXI-XXIX). Only the relatively stable sydnonyl-methylene cations are formed. With consistent formation of [M + 18]+ ion as the base peaks with simple spectra, the NH3 CI-MS can be an excellent method for the molecular weight determination. 相似文献
13.
14.
15.
16.
《Analytical letters》2012,45(6):573-580
Abstract Steroids, including cortisone, Cortisol, aldosterone, cortol, preg-nanediol, androsterone and 4-androsten-3, 17-dione can be ionized directly, without derivative formation, by plasma desorption ionization to give characteristic mass spectra. The ion products, with isobutane as the reagent gas, indicate the nature of the functional groups and the molecular formula; the spectra are similar to those obtained by chemical ionization methods. 相似文献
17.
碘代烷烃在532 nm激光作用下多光子电离解离机理 总被引:3,自引:0,他引:3
利用532nm的激光对碘代烷烃(碘甲烷、碘乙烷、碘代正丙异丙烷)分子作了多光了电离解离(MPID)质谱(MS)研究,在532nm激光作用下,CH3I分子吸收532nm激光双光子的能量,进入A带的IA2态,继续吸收光子上泵浦至电离态形成母体离子CH3I,然后再形成碎片离子;而其它几个碘代烷烃吸收双光子的能量进入A带后均形成中性碎片,中性碎片再吸收光子经一系列电离解离形成碎片离子,此外,本文还通过对同 相似文献
18.
19.
Amino acid thiophosphoramidates of nucleoside were synthesized and determined by negative ion electrospray ionization mass spectrometry (ESI‐MS) in conjunction with tandem mass spectrometry (MS/MS). Hie fragmentation pathways were investigated. The results show that ESI‐MS is a useful tool for structural determination of amino acid thiophosphoramidates of nucleoside. 相似文献