[Studies of black roller pen inks by NIR FT-Raman spectrometry]

36 kinds of black roller pen inks collected from Chinese market were analyzed by NIR FT-Raman spectroscopic technique and they were divided into 10 groups (from A to J group) according to their characteristic Raman spectra. Based on studying main component of roller pen inks and peculiarity of Raman spectrum by documents, the main Raman peaks of each group of roller ball inks were interpreted particularly. It have also been investigated that the influence factors from paper matrix, humidity of the samples, laser power and writing time, especially the forth item showed some relationships of the peak intensity ratio with the relative age of inks. This method is speediness, convenience, high sensitivity and no ink-extraction process. The insufficiency of the method is that fluorescence and heat background comes forth when a few samples were irradiated by laser.