Fast detection of chemical warfare agent simulants by photoacoustic spectroscopy

Photoacoustic spectroscopy (PAS) is a highly sensitive sensor for trace gases and is widely used. It is a research hotspot for detecting chemical poisons and toxic gases. A spectrum measurement platform based on quantum cascade laser (QCL) and a temperature-controlled photoacoustic cell were designed and constructed. Based on this, the photoacoustic spectroscopy method was established to test objects with distinct physical and chemical properties, using dimethyl methyl phosphate (DMMP) and dichloromethane (CH₂Cl₂) as research subjects. Photoacoustic spectroscopy has been successfully used to detect chemical agents in a wide concentration range of DMMP. The concentration range of 40 mg/m3 ~ 787.05 mg/m³ exhibits strong absorption and spectral characteristics. The test results confirm that photoacoustic spectroscopy detection technology is not dependent on detection wavelength, unlike traditional spectroscopy detection technology. This demonstrates the extensive application of this detection technology and provides a technical way for rapid on-site screening.