Koenig Agnès, Weyermann Céline
Ecole des Sciences Criminelles, Université de Lausanne, Batochime, 1015 Lausanne-Dorigny, Switzerland.
Ecole des Sciences Criminelles, Université de Lausanne, Batochime, 1015 Lausanne-Dorigny, Switzerland.
Sci Justice. 2018 Jan;58(1):17-30. doi: 10.1016/j.scijus.2017.08.002. Epub 2017 Aug 8.
The development of ink dating methods requires an important amount of work in order to be reliably applicable in practice. Major tasks include the definition of ageing parameters to monitor ink ageing. An adequate parameter should ideally fulfil the following criteria: it should evolve as a function of time in a monotonic way, be measurable in a majority of ink entries, be as accurate and reproducible as possible, and finally it should not be influenced too much by transfer and storage conditions. This work aimed at evaluating the potential of seven ageing parameters for ink dating purposes: the phenoxyethanol quantity, relative peak areas (RPA), three solvent loss ratios (R%, R%*, NR%) and two solvent loss parameters (R NR). These were calculated over approximately one year for 25 inks selected from a large database to represent different ageing behaviours. Ink entries were analysed using liquid extraction followed by GC/MS analysis. Results showed that natural ageing parameters (NR% and NR) were not suitable ageing parameters for ink entries older than a few weeks. RPA used other compounds present in ink formulations in combination to PE in order to normalise the results. However, it presented particular difficulties as they could not be defined for all inks and were thus applicable only for 64% of the studied inks. Finally, the PE quantity, R% and R allowed to follow the ageing of the selected inks over the whole time frame and were identified as the most promising. These were thus selected to test three different interpretation models in the second part of this article. The possibilities and limitations of ink dating methods will be discussed in a legal perspective.
墨水年代测定方法的发展需要大量工作，以便在实践中可靠应用。主要任务包括定义用于监测墨水老化的老化参数。理想情况下，一个合适的参数应满足以下标准：它应随时间单调变化，在大多数墨水样本中可测量，尽可能准确且可重复，最后它不应受转移和储存条件的太大影响。这项工作旨在评估七个老化参数用于墨水年代测定的潜力：苯氧乙醇含量、相对峰面积（RPA）、三个溶剂损失率（R%、R%*、NR%）和两个溶剂损失参数（R NR）。从一个大型数据库中选取了25种墨水，代表不同的老化行为，对其进行了大约一年的这些参数计算。通过液液萃取后进行GC/MS分析来分析墨水样本。结果表明，对于存放几周以上的墨水样本，自然老化参数（NR%和NR）不是合适的老化参数。RPA结合墨水中存在的其他化合物与苯氧乙醇一起使用，以便使结果标准化。然而，它存在特殊困难，因为并非所有墨水都能定义这些参数，因此仅适用于64%的研究墨水。最后，苯氧乙醇含量、R%和R能够在整个时间范围内跟踪所选墨水的老化情况，并被确定为最有前景的参数。因此在本文的第二部分选择这些参数来测试三种不同的解释模型。将从法律角度讨论墨水年代测定方法的可能性和局限性。
