Quantification of low molecular weight fatty acids in cave drip water and speleothems using HPLC-ESI-IT/MS — development and validation of a selective method
Quantification of low molecular weight fatty acids in cave drip water and speleothems using HPLC-ESI-IT/MS — development and validation of a selective method
复制标题
DOI：
10.1007/s00216-014-7743-6
复制
发表时间：
2014-03
影响因子：
4.3
通讯作者：
Janine Bosle;Simon A Mischel;A. Schulze;D. Scholz;T. Hoffmann
中科院分区：
文献类型：
--
作者：
Janine Bosle;Simon A Mischel;A. Schulze;D. Scholz;T. Hoffmann
本研究提出了一种分析洞穴滴水和洞穴中低分子量脂肪酸的新方法。该方法的开发包括样品制备过程的优化，例如空白还原、固相萃取、提取物浓度以及液相色谱-电喷雾离子阱质谱（HPLC-ESI-IT/MS）测量参数。五种分析物（月桂酸、肉豆蔻酸、棕榈酸、硬脂酸和花生酸）的保留时间在5 ~ 13.5 min之间。进行了添加实验以完成外部校准，其范围从12.5到75 ng每个添加水样。相关系数为0.9558 ~ 0.9989。批间精密度（以三个重复的相对标准偏差表示）< 7%。不同分析物的检出限为0.77 ~ 55.97 ng；回收率从30%到103%不等。首次应用时，对Herbstlabyrinth-Adventhöhle洞穴系统的洞穴滴水和石笋样品进行了分析。水样的浓度范围为38.37至9,982.54 ng L - 1，石笋的浓度范围为2.52至1,344.96 ng g - 1。因此，不同的脂肪酸表现出明显的差异。短链脂肪酸表现出相似性，而花生酸表现出相反的趋势。发现了不同的相关性，可以提高对水滴运输和洞穴中保存的脂质的不同有机来源的认识。这种新方法提供了一个更具选择性的提取过程，特别是调整到低分子量脂肪酸，因此减少了所需的样本量。该方法不仅适用于石笋样品，也适用于洞穴滴水样品。
This study presents a novel method for the analysis of low molecular weight (LMW) fatty acids in cave drip water and speleothems. The method development included optimization of sample preparation procedures, e.g., blank reduction, solid phase extraction, concentration of extracts as well as liquid chromatography coupled to electrospray ion-trap mass spectrometry (HPLC-ESI-IT/MS) measurement parameters. Retention times for five analytes (lauric acid, myristic acid, palmitic acid, stearic acid and arachidic acid) were between 5 and 13.5 min. Spiking experiments were performed to accomplish external calibrations which ranged from 12.5 to 75 ng per spiked water sample. The correlation coefficient ranged from 0.9558 to 0.9989. Inter-batch precision, expressed as the relative standard deviation of three replicates, was <7 %. Limits of detection ranged from 0.77 to 55.97 ng for the diverse analytes; obtained recoveries varied from 30 to 103 %. For a first application, cave drip water and stalagmite samples from Herbstlabyrinth-Adventhöhle cave system were analyzed. Concentrations ranged from 38.37 to 9,982.54 ng L−1for water samples and 2.52 to 1,344.96 ng g−1for the stalagmite. Thereby, the different fatty acids showed a distinctive variation. Whereas shorter-chained fatty acids exhibited similarities, arachidic acid showed opposite trends. Diverse correlations were found, which could improve the understanding of different organic sources of the lipids transported by drip water and preserved in speleothems. This new method provides a more selective extraction process, particularly adjusted to LMW fatty acids and therefore reduces the required sample size. Furthermore, it is applicable to stalagmite as well as cave drip water samples.