Rapid hydrocarbon analysis using a miniature rectilinear ion trap mass spectrometer

Abstract

A miniature ion trap mass analyzer was applied to the analysis of traces of hydrocarbons and simple heteroatomics in the vapor phase and in aqueous solution. Vapors of acetone, acetic acid, acetonitrile, benzene, butanethiol, carbon disulfide, hexane, dichloromethane, naphthalene, toluene and xylenes were detected and quantified using solid sorbent trapping and, in some cases, by passage through a membrane interface. Aqueous solutions of benzene, toluene, xylenes, hexane and a petroleum naphtha distillate were examined using the membrane interface. Sampling, detection and identification of all compounds was completed in times of less than one minute. The gas-phase samples of toluene and benzene were detected at 200 ppt (limit of detection, LOD) for toluene and 600 ppt for benzene. Identification of benzene and xylene in aqueous solutions was readily achieved with LODs of 200 and 400 ppb, respectively. Quantification over a linear dynamic range of two orders of magnitude for the aqueous samples and three orders of magnitude for the vapor-phase samples was demonstrated.

Direct detection of benzene, toluene, and ethylbenzene at trace levels in ambient air by atmospheric pressure chemical ionization using a handheld mass spectrometer

“…Several versions of portable mass spectrometers have been used for in situ gasphase chemical analysis [20,21] based on selective membrane sampling [22][23][24][25]. A related sorbent introduction system using preconcentration in a solid matrix and thermal release was employed to achieve trace level detection of benzene with the handheld Mini 10.5 [26]. These successful methods still require some time (usually tens of seconds) for preconcentration but the emergence of simple ambient ionization methods [27,28] could avoid the necessity for any sample pretreatment; when coupled with a miniature mass spectrometer, this combination should allow in situ, and virtually instantaneous, analysis.…”

In Situ Analysis of Organic Material with a Portable Mass Spectrometer

“…A similar sorbent based sample introduction system had been demonstrated in the lab setting with a miniature instrument for the detection of toxic chemicals (Keil et al 2008) and volatiles from gasoline (Sokol et al 2008). …”

Ion isolation and collision-induced dissociation in a 0.5mm ro cylindrical ion trap

“…This geometry can be manufactured with precision using silicone-on-insulator (SOI) deep reactive ion etching (DRIE) [8]. A miniature CIT has the advantage of reduced power and voltage requirements as the trap size is decreased [22]. Currently, the CIT is the most favorable choice for miniaturization due to its independence from the length parameter and potential for expanding analysis via MS n experiments.…”