Analysis of Organic Acids in Human Dental Plaque by Means of Gas Chromatography/Mass Spectrometry
牙菌斑有机酸的气相色谱-质谱分析

The purpose of this study was to investigate the composition of plaque fatty acids in the healthy population. The study was made on 10 volunteers over the age of 18 who were divided into three sub-groups (3-4 individuals). Neither subject exhibited clinical evidence of salivary gland disorder and any medication affecting salivary functions were not used. A sensitive GC/MS method with VG7070E mass spectrometer was developed in our study. The sample separation was carried out on a fused silica capillary column with OV-1. The column size was 23 m x 0.23 mm. The temperature program was as follows: from 40 degrees C to 120 degrees C fast, then from 120 degrees C to 240 degrees C at 6 degrees C/min. The results showed that there were 14 organic acids and isomers present in plaque. They were C12:0, C14:0, C15:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:0 and phenylacetic acid, phenylpropionic acid. The higher content of fatty acids in the sample were C16:0, C18:0, and C18:1. The aromatic acids were detected only in some samples. The odd-numbers fatty acids and aromatic acids were for the first time detected. The origin of organic acids in plaque is an ongoing area of research. Our data clearly identify the bacterial contribution to the organic acids of plaque matrix, which may have a special relationship with bacteria metabolism. The research will help us to understand fatty acids metabolism of dental plaque and to determine their role in the microbial homeostasis of dental plaque.