山核桃外蒲壳化学成分初步分析及总黄酮含量测定

目的初步确定山核桃外蒲壳主要化学成分并测定总黄酮的含量。方法将山核桃外蒲壳分别用热水、950ml／L乙醇、石油醚提取后，经试管预试法、薄层层析色谱法和纸层析色谱法初步确定山核桃外蒲壳主要化学成分；用硝酸铝-亚硝酸钠显色，采用紫外分光光度法测定山核桃外蒲壳总黄酮含量。结果浓度在4．99～99．80μg／ml时与吸收度呈良好的线性关系，回归方程：A=0．01117c-0．022，r=0．9995；回收率为106．37％，RSD=2．47％。结论该方法操作简单，重复性好，结果准确可靠，可用于山核桃外蒲壳化学成分初步分析和总黄酮的含量测定。     

The effects of four different solvent vapours on the restoration of obliterated stamp markings from five different wooden surfaces

The stamp markings on wooden surfaces, which are placed on trees and products including antiques, indicate the status of trees and involve identifying data regarding the products. Such markings are obliterated either to facilitate illegal logging or to conceal product information. Despite the wide literature on the restoration of obliterated characters on metal and polymer surfaces, the recovery of defaced characters on wooden surfaces appears to be understudied. Several reference texts in the forensic marks’ examination literature suggest that water, water vapor, and alkaline solutions are useful in restoring the abraded markings on the wood. Since there does not seem to be any experimental study proving such success, this study aimed to fill this gap. This study conducted experimental research by using water, ethanol, ammonia, and chloroform to recover the scraped characters on samples obtained from walnut, beech, spruce, oak, and cedar trees. The cold-stamped characters, which were defaced at varying depths, were restored using vapor and liquid phases of four solvents. While the vapor phases of water, ethanol, and ammonia yielded good outcomes on all types of wooden surfaces, the liquid phases did not seem to be useful in the revisualization process. The response of the vapors, which varied between 62 and 220 s, depended on the type of wood. The restoration technique developed in this research offers the possibility of on-site usage, easy application, utilization of low-cost solvents, rapid recovery, and effectiveness on various wooden surfaces. Overall, the restoration methodology used in this research appears to be fruitful in retrieving identifying information on wooden samples.