摘要
目的考察光照、温度和湿度对于中性笔墨迹中PEG低聚物降解变化的影响。方法选用PEG分布不同的6支黑色中性笔平行制样,分别放置在250 W/m2辐照强度(40℃)的光照环境、80%RH(25℃)的高湿度环境和40℃高温环境下老化,应用液相色谱-高分辨质谱(LC-HRMS)定期检测样品中PEG各低聚物的相对含量比值R。结果 6支中性笔墨迹中R值变化趋势相同。有光照老化条件下,PEG降解最快。在同样避光的情况下,高温环境下PEG的降解速度比高湿度环境下快。高湿度环境下PEG的降解主要是微生物引起的生物降解。结论在实际文件保存环境中,光照和温度将是影响中性笔墨迹中PEG低聚物降解的主要因素。
Objective To investigate the effects of environmental parameters on the degradation of PEG oligomers in black gel ink entries.Method Six black gel inks with different distribution of PEG oligomers were used to draw ink entry samples.Then they were kept in three environments for artificial ageing:light exposure(250W/m2,40℃),high humidity(80Y RH,25℃)and high temperature(40℃).The aged samples were analyzed at different time by LC-HRMS to calculate the relative peak intensity of PEG oligomers(R).Results Six gel inks with different PEG distributions showed the same decreasing trend of R.In the ink samples that were exposed to light with the presence of air flow,PEG oligomers degraded fastest.On the other hand,both in dark environment,the degradation rate of PEG oligomers in the high temperature environment was faster than that in the high humidity environment.For the latter,the degradation of PEG oligomers was mainly caused by microorganisms.Conclusion Since a high humidity environment is rare for file preservation,light and temperature will be the main factors that affect the degradation of PEG oligomers in gel ink entries.
作者
孙其然
张清华
王雅晨
杨旭
SUN Qi-ran;ZHANG Qing-hua;WANG Ya-chen;YANG Xu(Shanghai Forensic Service Platform,Academy of Forensic Science,Shanghai 200063,China)
出处
《中国司法鉴定》
2018年第2期37-41,共5页
Chinese Journal of Forensic Sciences
基金
十三五国家重点研发计划(2016YFC0800705)
中央科研院所公益项目(GY2014G-3)
上海市司法鉴定专业技术服务平台(16DZ2290900)