TDS-GC/MS法检测黑色中性笔墨迹中挥发性溶剂的历时性变化

目的应用热脱附-气相色谱/质谱(TDS-GC/MS)分析,研究7支黑色中性笔墨迹中挥发性溶剂的历时性变化规律。方法选取7支不同品牌的黑色中性笔,分别在A4纸和笔记本上进行一次制样,然后在不同时间点取样,应用所建TDS-GC/MS方法分析墨迹中乙二醇、二甘醇和三甘醇在200余天内的含量变化。结果6支笔中的乙二醇、三甘醇的含量在2个月之内有明显的下降,另1支笔中二甘醇的含量在5个月内还能观察到较明显的下降。目标物的历时性变化趋势能拟合成幂函数或对数函数。不同的纸张、不同的墨水对检测结果均有影响。结论黑色中性笔墨迹中的挥发性溶剂的含量随时间增加而下降,应用所建TDS-GC/MS方法,能为判断需检墨迹是否处于溶剂含量明显变化的阶段提供依据。

Study of Diachronic Change of Solvents in Black Gel Ink Entries by TDS-GC/MS

Objective To study the diachronic change of volatile solvents in seven black gel ink entries by thermal desorption-gas chromatography/mass spectrometry(TDS-GC/MS).Methods Seven black gel ink pens of different brands were used to make ink samples on A4 paper and notebook.Then samples were taken at different time points,and analyted by the established TDS-GC/MS method for ethylence glycol,diethylene glycol and triethylene glycol in the ink for more than 200 days.Results The content of ethylene glycol and triethylene glycol in 6 gel ink pens decreased significantly within 2 months,while the content of diethylene glycol in the other pen decreased significantly within 5 months.The diachronic change of the analytes can be fitted into a power function or a logarithmic function.Different paper and ink formula have an impact on the results.Conclusion The content of volatile solvents in black gel ink entries decreases with time.The established TDS-GC/MS method can provide a basis for judging whether the questioned ink sample is at a stage where the solvent changes significantly.