Continuous water infusion enhances atmospheric pressure chemical ionization of methyl chloroformate derivatives in gas chromatography coupled to time-of-flight mass spectrometry-based metabolomics.
Continuous water infusion enhances atmospheric pressure chemical ionization of methyl chloroformate derivatives in gas chromatography coupled to time-of-flight mass spectrometry-based metabolomics.
复制标题
DOI：
10.1021/ac502133r
复制
发表时间：
2014-09
影响因子：
7.4
通讯作者：
Christian J. Wachsmuth;K. Dettmer;S. Lang;M. Mycielska;P. Oefner
中科院分区：
文献类型：
--
作者：
Christian J. Wachsmuth;K. Dettmer;S. Lang;M. Mycielska;P. Oefner
采用气相色谱-飞行时间质谱法研究了连续输水对代谢物中氯甲酸甲酯（MCF）和甲氧肟-三甲基硅基（MO-TMS）衍生物常压化学电离效率和可重复性的影响。以0.4 mL/h的流速输水，通过抑制源内破碎，不仅使20种mcf衍生代谢物标准品的准分子离子强度平均增加16.6倍，而且获得了最可重复的峰面积积分。水分对二羧酸的影响最大，对（杂）芳香化合物的影响最小。在人血清提取物中加入相同的20种mcf衍生代谢物标准物，水灌注也提高了可靠检测折叠变化的能力，小至1.33倍。另一方面，MO-TMS衍生物没有受到水灌注的显著影响，无论是在它们的碎片模式上，还是在检测差异调节化合物方面。作为原理证明，我们应用MCF衍生化和GC-APCI-TOFMS检测17-DMAG治疗后胰腺癌细胞中代谢物丰度的变化。注水不仅增加了通过准分子离子鉴定的代谢物数量，而且提高了峰面积的重现性，从而使显著调节代谢物的数量几乎增加了一倍（假发现率< 0.05），达到23个。
The effects of continuous water infusion on efficiency and repeatability of atmospheric pressure chemical ionization of both methyl chloroformate (MCF) and methoxime-trimethylsilyl (MO-TMS) derivatives of metabolites were evaluated using gas chromatography-time-of-flight mass spectrometry. Water infusion at a flow-rate of 0.4 mL/h yielded not only an average 16.6-fold increase in intensity of the quasimolecular ion for 20 MCF-derivatized metabolite standards through suppression of in-source fragmentation but also the most repeatable peak area integrals. The impact of water infusion was the greatest for dicarboxylic acids and the least for (hetero-) aromatic compounds. Water infusion also improved the ability to detect reliably fold changes as small as 1.33-fold for the same 20 MCF-derivatized metabolite standards spiked into a human serum extract. On the other hand, MO-TMS derivatives were not significantly affected by water infusion, neither in their fragmentation patterns nor with regard to the detection of differentially regulated compounds. As a proof of principle, we applied MCF derivatization and GC-APCI-TOFMS to the detection of changes in abundance of metabolites in pancreatic cancer cells upon treatment with 17-DMAG. Water infusion increased not only the number of metabolites identified via their quasimolecular ion but also the reproducibility of peak areas, thereby almost doubling the number of significantly regulated metabolites (false discovery rate < 0.05) to a total of 23.