[Detection of TVOC and odor in industrial park using electronic nose].

The main volatile compounds belong to TVOC or odor which may generate from industrial park,special sensors were adopted to build electronic nose for detecting those compounds. TVOC pollution index (TPI) and odor pollution index (OPI) were designed as well as detecting method based on electronic nose in the field. On this basis, considering the pollution situation of chemical industrial of Zhapu port in Jiaxing, six detecting points were selected to be tested by electronic nose on site. Each sensor responses processed by principal components analysis (PCA), two principal components were extracted, that is, eight sensors can be divided into two groups including the types of TVOC (S1) and odor (S2-S8). Meanwhile, the on site collected samples were qualitatively analyzed with GC/ MS. At each testing point, integral area percentage of the compounds being a part of TVOC accumulated mostly over 90% and to odor, mostly was below 10%. Results show: (1) Choosing appropriate sensors combining PCA can preliminarily reflect the pollution condition of TVOC and odor in industrial park; (2) Combining pollution indexes measured with electronic nose and results of qualitative analysis with GC/MS can generally concluded the overall pollution situation of TVOC and odor in industrial park and distribution of each pollutant; (3) Application of electronic noses and GIS to detect TVOC and odor in industrial park can preliminary assess space pollution situation in industrial park.

[Applied study on clustering of variables around latent components method in wavelength region selection with near-infrared spectroscopy].

The present paper introduced the principle of clustering of variables around latent components method, and used this method in selecting spectrum range of the NIR quantitative analysis models. Taking tobacco samples as experiment materials, we dealed with 107 sample spectra, divided the spectra into 5 clusters, and explained the information reflected by each of these 5 clusters in terms of chemistry. On this basis, we chose the corresponding wavelength range to set up the quantitative models of the total sugar, reducing sugar and nicotine by PLS method. Compared with the model based on the full NIR spectral range, Rtraining of the models based on the chosen spectral range rose from 0.977 1, 0.917 2 and 0.987 4 to 0.995 5, 0.975 1 and 0.994 4; Rtest rose from 0.977 8, 0.941 2 and 0.993 2 to 0.992 7, 0.967 9 and 0.994 0; RMSECV dropped from 1.09, 1.43, 0.14 to 1.05, 1.05 and 0.13, RMSEP dropped from 0.92, 1.17 and 0.16 to 0.39, 0.63 and 0.11 and the D value dropped from 1.274%, 1.972% and 0.829% to 0.711%, 0.843% and 0.768% for the total sugar, reducing sugar and nicotine, respectively. These data indicated that this method can improve the forecasting precision and stability of the model, so offers certain guidance on practical application.