Synthetic green copper-arsenic pigments include two pigments: shale green (CuHAsO3) and emerald green (3Cu(AsO2)2.Cu(CH3CO)2)
,which were common in Europe in the 18th and 19th centuries. During the Qajar period, these two pigments were introduced to Iran due to trade with the West, and due to their cheapness and transparency, they quickly replaced other green pigments such as verdigris and malachite. The purpose of this study is to investigate the presence of these pigments in Qajar period paintings and to choose the best method to identify these two pigments. For this purpose, green was sampled from a painting on glass, a painting on wood, a mural, and a manuscript, all of which belonged to the Qajar period. To identify the pigments, instrumental methods such as Fourier transform infrared spectroscopy (FTIR) equipped with an ATR reflection cell, X-ray diffractometry (XRD) and scanning electron microscopy equipped with an X-ray dispersive X-ray (SEM/EDX) were used . The results proved the presence of emerald green in the painting behind the glass of the Rashvand Khaneh in Qazvin, the wall painting of the Karimkhani Citadel in Shiraz and the decorations used in a Quranic manuscript and Shaileh green in the painting on the wood of the Saqanfar in Babylon. The results also showed that the best and fastest method for analyzing these two compounds is FTIR, which can identify these two pigments with a minimum sample and distinguish them from each other due to their structural differences.

Evaluation of the degradation and stability of soot ink made based on ancient texts under aging conditions. Soot ink is one of the inks that has been widely used in written works. Some of which are currently in our custody, so it is necessary to examine their degradation in order to prevent their further degradation. In this regard, in the present study, the degradation rate and stability of soot ink were investigated. The question of this study is what level of degradation and stability do the manufactured inks have? The purpose of this study was to examine soot ink, which was used in paper works, using laboratory instruments, pH meter, FTIR, optical microscope, colorimeter, and tensile strength meter.
To prepare the samples, the immersion method was used to impregnate the paper with ink, and an incubator was used to age the samples. The results of the acidity test (pH measurement) of the ink-impregnated papers show that the accelerated moisture-thermal aging process, especially after a period of 12 days, causes a decrease in pH compared to the samples before aging. The results of microscopic observations show that the aged sample has suffered from breakage in addition to the ink of the paper fibers. Analysis of the ATR-FTIR spectra in the carbon black sample indicates that cellulose undergoes structural changes during aging, but most of the changes are in the structure of the ink. According to the studies conducted, the results of this research indicate that the carbon black ink has relatively good stability during aging.