Szopa C, Sternberg R, Coscia D, Cottin H, Raulin F, Goesmann F, Rosenbauer H
Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR 7583 CNRS, Université Paris 7, Créteil, France.
J Chromatogr A. 1999 Nov 26;863(2):157-69. doi: 10.1016/s0021-9673(99)00988-7.
The development of a gas chromatograph for the cometary sampling and composition (COSAC) experiment is described in the context of the preparation for the European Space Agency (ESA) Mission Rosetta for investigation of a cometary nucleus. COSAC is one out of ten experiments on the Rosetta Lander. Its scientific goal is to analyze in situ the chemical composition of the volatile constituents of the nucleus of the target comet P/Wirtanen. Constituted of several (up to eight) capillary wall-coated and porous-layer open tubular columns operating in parallel, the GC system is designed to separate and identify both organic and inorganic compounds which evolve from the comet naturally or are obtained from cometary samples through stepwise heating in a miniaturized pyrolizer. In this first part of our study, dimethylpolysiloxane (DMPS) stationary phases with increasing percentages of diphenyl substituted group (DP) have been investigated. A coupled experimental and theoretical approach has been taken in order to predict chromatographic data. By the use of a four-point experimental calibration (0 to 65% diphenyl group) in conjunction with Pro ezGC modeling software, results in prediction of multicomponent chromatograms with a mean error less than 5% for each compound retention time were obtained, irrespective of the stationary phase's diphenyl content and column physical parameters. The possibility to associate such phases is illustrated by the evolution of coelutions obtained on a non-polar (100% DMPS) and a medium polar (65% DP-DMPS) stationary phase, respectively. This study showed that with a small number of well tuned DP-DMPS columns, the separation and identification of most of the targeted compounds can be achieved with a minimum amount of coelutions and within the experiment requirements.
本文在欧洲航天局（ESA）罗塞塔号彗星核研究任务的准备工作背景下，描述了用于彗星采样与成分分析（COSAC）实验的气相色谱仪的研制情况。COSAC是罗塞塔号着陆器上的十个实验之一。其科学目标是对目标彗星46P/维尔特宁核的挥发性成分进行现场化学成分分析。该气相色谱系统由几根（最多八根）并行运行的涂壁多孔层开管柱组成，旨在分离和识别从彗星自然逸出或通过小型热解器逐步加热从彗星样本中获得的有机和无机化合物。在我们研究的第一部分，研究了二苯基取代基（DP）百分比不断增加的二甲基聚硅氧烷（DMPS）固定相。为了预测色谱数据，采用了实验与理论相结合的方法。通过使用四点实验校准（0至65%二苯基）并结合Pro ezGC建模软件，得到了多组分色谱图的预测结果，每种化合物保留时间的平均误差小于5%，与固定相的二苯基含量和柱物理参数无关。分别在非极性（100%DMPS）和中极性（65%DP-DMPS）固定相上获得的共洗脱情况的演变说明了关联这些固定相的可能性。这项研究表明，使用少量经过良好调整的DP-DMPS柱，在共洗脱最少且符合实验要求的情况下，能够实现对大多数目标化合物的分离和鉴定。
