采用傅里叶变换红外光谱法对不同产地、不同牌号及同一牌号不同型号的122种黑色签字笔字迹进行了种类鉴别.以乙腈-水以体积比60比40作为提取剂,分别对122种黑色签字笔字迹进行了提取,根据提取效果的不同,分为可溶(63种)和不可溶(59种)两大类.然后对黑色签字笔字迹进行了傅里叶变换红外光谱测定,根据红外光谱图中特征峰数目的不同,吸收峰的峰位及峰面积比或峰高比的异同进一步进行区分,从而达到对黑色签字笔字迹油墨进行种类鉴别.对红外光谱测定的有关因素如:与溴化钾混合及压片的试样制备,写有字迹纸张的质量,以及不同波长及时间的紫外光照等也作了试验.

FT-IR-spectrometry was applied to the identification and differentiation of gel pen ink of different catagories extracted from handwriting with the solvent mixture of acetonitrile and water mixed in the ratio of 60 to 40 by volume.A total of 122 kinds of ink of different categories were taken as testing samples,and based on their efficiency of extraction,the ink samples were divided into 2 groups,i.e.,the solubles (63 kinds) and the insolubles (59 kinds).Further identification of the ink samples was performed by the FT-IR-spectrometry through inspection of number of characteristic peaks,position of the peaks and ratio of peak heights obtained from the IR-spectra,and informatoins about constituents of the ink sample,including the solvents,surfactants,resins and colorants used in making the ink,were obtained.Various influential factors to the IR-spectrometry,i.e.the sample preparation by grinding with KBr and pressing into pellets,the quality of paper on which handwritings were made and the UV-radiation at different wavelengths and for different time,were also studied.