Novel analytical method based on Fourier Transform assisted Ultraviolet-Infrared dual resonance spectroscopy for aerosol speciation

Abstract

Detecting aerosols have been treated as one of the most important environmental challenges among the scientists. However, the current existing methods for aerosl detection and recongition (such as spectroscopy) cannot often be considered as favorable detection system, mostly attributed to their low recovery detection limitations, high cost, not-real time, etc. So, in the current study an optical detection device with three main parts (light sources, a 20-membered optical detection array and a digital versatile disc) has been introduced by fourier transform assisted ultraviolet-infrared dual (double) uresonance spectroscopy. For this purpose, a square matrix 10 × 10 dimension with five independent 4 × 4 sub-matrices (D1-D5) was defined as the responsoble model. This selection was based on the selective classification (clustering) of the measured results at the molecular levels of the tested aerosols. Then, the middle infrared (Middle-IR) region was divided into nine parts with 13.33 nm resolution. About the SiO2 and water aerosols, determinant percentages of D3 and D1 matrixes pocessed partially high and significant values. Besides, correlation between the determinant percentages of D1 and D4 as well as D2 and D5 revealed the reproducibility of the introduced detection system and the suggested model. The reliability of the detection system was also evaluated via introducing different two-mixture standard samples of the areoles and predication of the types of the introduced samples into the detection system. Capability determination and selective probes of this method have also been investigated for different analytical concentrations of CH3COOH in water samples at the mid-IR region under similar conditions (Average population: 200 ± 5 particles per each m3 sample). Further, its behavior was evaluated by analysis of different volatile homologs such as HCOOH, CH3COOH and C2H5COOH with acceptable response times and correlation coefficents.