Abstract: The modified WQF-500 FTIR spectrometer from the Second Optical Instrumental Factory and an accessory(SpecTech)of mid-IR fiber optics with an ATR probe were used to detect the skin covering a parotid gland using. In this investigation, forty patients with tumor of salivary gland were performed with FTIR fiber optics measurement. The differential diagnosis from the obtained FTIR spectra of benign and malignant tumors of salivary gland was compared with pathological diagnosis, which is considered as the standard. Good agreements were found between the results of pathological diagnosis and those of spectral detection. The results show that the difference lied in the obtained FTIR spectra of the skin covering benign and malignant tumors of salivary gland and normal parotid gland. And the difference can be characterized by the band width, peak position and peak intensity. Based on the difference of the bands in the range of 1500—1000 cm^-1, malignant tumor can be classified into two types. The first type of tumor(for example acinic cell carcinoma, oxyphilic cell adenocarcinoma, adenoid cystic carcinoma and so on) possesses the above spectra feature. Along with the variation of species(for example malignant lymphoma, lympho-epithelial carcinoma and so on), great changes take place in band width, peak position and relative intensity of the bands between 1500 and 1000 cm^-1 in spectra of the other kind of malignant tumor. So the FT-mid-IR spectroscopy is a promising technique which will become a non-invasive, quick, accurate and convenient method to diagnose malignant and benign tumor of salivary gland early.

Key words: FT-mid-IR fiber optics spectroscopy, Attenuate total reflection(ATR), Parotid gland, Mid-IR fiber optics