Simple method for adiabatically sampling reactive gaseous systems for mass spectrometric analysis

Abstract

An accurate and simple method of measuring relative mass spectrometric sensitivities An ~nderstanding of the nature of the chemical processes occuring in dynamic, reactlve, gaseous systems, such as hydrocarbon flames and chemical lasers requires knowledge of the chemical species that actually exist· in these sys~ems.This paper reports th~ design and use of a flow-type reactor tube which is passed thro~gh the ion source of a mass spectrometer permitting the components of a reactlDg gas phase system to be extracted adiabatically through a 10 ,." orifice into the ion source for analysis. The procedure for drilling this orifice with a focused CO 2 laser is presented, together with data which indicate that the reactive species extracted from a flame zone are representative of those existing within the reactive system.

Direct Determination of Product Branching for the NH2 + NO Reaction at Temperatures between 302 and 1060 K

“…14,15 The sampling technique had been extensively applied by Gutman, Slagle, and collaborators [16][17][18] in conjunction with the excimer-laser generation of radical reactants. NH 2 radical was produced by photolysis of NH 3 at 193 mm.…”

Kinetics of C6H5 radical reactions with 2-methylpropane, 2,3-dimethylbutane and 2,3,4-trimethylpentane

“…NO titration revealed that on average about 62 -69% of the dissociated acetophenone produced the C 6 H 5 radical. C 6 H 5 COCH 3 carried by an excess amount of He was premixed in corrugated stainless steel tubing with C 4 H 10 before being introduced into the Saalfeld-type quartz reactor [17,18] and the products of the photoinitiated reaction were supersonically sampled and ionized by electron-impact ionization. The mole fractions of C 6 H 5 COCH 3 and 2-methylpropane were typically Ͻ 0.1% and ϳ33%, respectively.…”

Mass-spectrometric determination of product branching probabilities for the NH2 + NO2 reaction at temperatures between 300 and 990 K

“…In this communication, we report the result of the first comprehensive product measurement for the NH, + NO, reaction using the laser photolysis/high-pressure sampling mass-spectrometric technique developed by Saalfeld [25,26], Gutman [27,28], and their collaborators.…”