Analysis of transient response of single quartz crystal nanobalance for determination of volatile organic compounds

Quartz crystal nanobalance (QCN) sensors are considered as powerful mass sensitive sensors. In this study, a single quartz crystal nanobalance modified with polystyrene has been employed to determine benzene, toluene, ethylbenzene and xylene (BTEX compounds). The frequency shift of QCN sensor was found to be linear against the BTEX compound concentrations in the range about 0–27 mg l−1. The correlation coefficients for benzene, toluene, ethylbenzene, and xylene were 0.9917, 0.9904, 0.9904 and 0.9925, respectively. The principal component analysis was also utilized to process the transient response data of the single quartz crystal, considering to the different adsorption–desorption dynamics of BTEX compounds. Using principal component analysis, it was found that over 75% of the data variance could still be explained by use of three principal components (PC1, PC2 and PC3). The score plot of the three first PCs data were used to classify and identify organic vapors. The results showed that the polystyrene modified QCN had favorable identification and quantification performances for the BTEX compounds.