Comprehensive two-dimensional gas chromatography for fingerprint pattern recognition in cachaca production
Comprehensive two-dimensional gas chromatography for fingerprint pattern recognition in cachaca production
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DOI：
10.1016/j.talanta.2007.07.021
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发表时间：
2008-01-15
期刊：
影响因子：
6.1
通讯作者：
Marriott, P. J.
中科院分区：
文献类型：
--
作者：
Cardeal, Z. L.;de Souza, P. P.;Marriott, P. J.
采用全二维气相色谱-飞行时间质谱联用技术（GC x GC/TOFMS）研究了不同木质材料在发酵过程中和老化后的Cachaca样品。香气化合物的分析后进行顶空固相微萃取法（HS-SPME）使用85 μ m聚丙烯酸酯（PA）纤维。蒸馏过程的指纹监测可以轻松确定过程的转折点，并对cabeca（头部），coracao（核心）和cauda（尾部）馏分进行高分辨率比较。不同木材材料的老化过程通过指纹相似性观察得到了很好的表征;在没有合适的度量来表达整体相似性的情况下，我们使用视觉和保留时间比较来识别重合峰和样品之间不同的峰。为了质量控制的目的，对所获得的等高线图进行简单观察就可以识别老化过程中使用的木材类型和老化过程，而无需进一步的统计处理或峰值识别。以这种方式，很容易找到在所研究的不同混合物之间最能区分的峰，即在蒸馏过程的每个阶段中鉴定出独特的化合物。在GC x GC实验中的二维极性/非极性色谱柱组中计算这些已鉴别化合物的近似第一维线性保留指数（LRI），并与质谱库搜索结合使用，以进行初步鉴别。沿着蒸馏过程的进展，70种化合物似乎可以在样品之间进行视觉区分，并指出了它们的保留指数，与文献数据具有良好的相关性。(C)2007 Elsevier B. V.保留所有权利。
Cachaca samples were studied by means of comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC x GC/TOFMS) during the fermentation process and after ageing in different wood materials. The analyses of the aroma compounds were performed after headspace-solid phase microextraction method (HS-SPME) using an 85 mu m polyacrylate (PA) fibre. Fingerprint monitoring of the distillation process allowed the easy determination of the turning points of the process and high-resolution comparison of cabeca (head), coracao (core) and cauda (tail) fractions. The ageing process in different wood materials was well characterised through fingerprint similarity observations; in the absence of a suitable metric for expressing the overall similarity, here we use a visual and retention time comparison to identify co-incident peaks and those that differ between samples. For quality control purposes, a simple observation of the contour plots obtained can thus allow the identification of the type of wood used in the ageing process, and the process of ageing, without further statistical treatment or peak identifications. In this manner, peaks, which discriminated most between the different mixtures studied were readily found, i.e. unique compounds were identified in each stage of the distillation process. Approximate first dimension linear retention indices (LRI) for these identified compounds were calculated in a bi-dimensional polar/non-polar column set in the GC x GC experiment and were used in conjunction with mass spectral library searching for tentative identification. Along the progression of the distillation process, 70 compounds appear to visually discriminate between samples and their retention indices are indicated, presenting good correlation with literature data. (C) 2007 Elsevier B.V. All rights reserved.