Development and application of a photoionization induced chemical ionization miniature ITMS for rapid and on-site analysis of odorous organic gases.

Odorous organic gases not only diminish psychological comfort but also impair public health and environmental ecosystems. Rapid detection of these gases is crucial for pollution source tracing, early warning, and health risk prevention. In this study, a newly developed miniature photoionization-induced chemical ionization ion trap mass spectrometer (PICI-ITMS) was adopted for rapid on-site detection of odorous organic gases. The integrated segmented quadrupole in the miniature PICI-ITMS synchronously and effectively improved the ionization efficiency and transmission efficiency over a broad mass range of 33-361 Da and a full width at half maximum of 0.354 @ m/z = 78. In addition, compared to the typical full scan mode, the pseudo-multiple ions monitoring mode demonstrated 10-fold and 16-fold sensitivity enhancement for benzene and toluene, respectively. Consequently, a high signal-to-noise ratio of 28.37 for 0.5 ppbv benzene was achieved within 1.5 s. Under the optimized condition, linear calibration curves ranging from 5 to 100 ppbv for the odorous organic gases (benzene, toluene, ethyl sulfide, ethyl acrylate and methyl sulfide) were obtained with R2 > 0.99. A good stability with the relative standard deviation of 6.00 % was obtained. The limits of detection (S/N = 3) for the investigated five odorous organic gases ranged from 0.32 to 0.85 ppbv. Ultimately, the performance of the miniature PICI-ITMS was demonstrated by rapid and on-site detecting the odorous organic gases released during garbage collection at bin sites by garbage truck and correction fluid usage.