小型两级腔光电离四极杆质谱仪的研制OA

Volatile organic compounds(VOCs)are major atmospheric pollutants,and developing rapid,accurate detection methods is crucial for environmental quality monitoring.To address the detection requirements of airborne VOCs,a new photoionization(PI)quadrupole mass spectrometry(QMS)system was developed in this study.In the initial design with a single chamber,a mismatch in operating pressure existed between the PI source and the quadrupole analyzer.Therefore,a novel two-stage chamber PI-QMS platform was developed and characterized.Specifically,the PI source operated in a higher-pressure front chamber to maximize ion yield,while the quadrupole analyzer functioned in a high-vacuum secondary chamber to ensure mass resolution.Furthermore,a segmented radio frequency(RF)quadrupole,optimized via simulation,was introduced into the front chamber to mitigate ion transmission losses under high-pressure conditions.An axial electric field was established by applying a gradient DC voltage,effectively enhancing the directional migration efficiency of the ions.Experimental results demonstrated that,compared to the single-chamber system,the two-stage design significantly reduced background noise and improved detection sensitivity by a factor of 40,achieving a limit of detection of 0.07 μL/L.The practical effectiveness of the platform was validated by analyzing air samples from a laboratory chemical cabinet,successfully identifying various VOCs such as toluene,trimethylbenzene,anisole,and acetone.This study provided a viable technical solution for the development of PI-QMS systems and the online monitoring of VOCs.