Abstract: Methods and apparatus for liquid sample introduction into chemical detectors that require the sample to be transformed from a flowing stream into either gaseous or particulate states. The effluent from either a process stream or a liquid chromatograph is nebulized by combined thermal and pneumatic processes within an inner fused silicon capillary tube heated by conduction from a surrounding electrical resistance heated outer capillary tube composed of a pure metal having a comparatively high linear relationship between temperature and electrical resistance to provide a uniform conduction of heat energy to the inner tube to form a well-collimated, partially or completely desolvated aerosol, with the less volatile solute components of the sample stream remaining in the particulate state. The gaseous components of the aerosol are separated from the solvent-depleted solute particles using either cryotrapping or momentum separation.

Abstract: Fluids entrapped in small confined within spaces of an object are analyzed by securing the object containing the confined space by epoxy to a small fitting over a notch applied on the object's surface adjacent to the confined space, the fitting being a slidable seal attached to a small tube which has a piercing device adapted to move with the small tube relative to the fitting and the object containing the confined space to puncture same through the notch, whereby the entrapped gaseous fluid in the confined space emerges into the fitting and small tube, the entire system being a sealed enclosure. Attached to the small tube is a capillary which leads to an analyzing device, such as a mass spectrometer.

Abstract: A preconcentrator for analyzing trace constituents in gases wherein a sample gas is introduced to a confined sorbent which thereafter is evacuated by a vacuum pump and a low-pressure carrier gas passes through the sorbent while it is desorbing, wherein the desorbed trace constituents are carried by the carrier gas to a detector that operates at low pressure such as a mass spectrometer. Because the mass of the carrier gas which carries the desorbed trace consituents to the detector is at a lower pressure and therefore has less density than the sample gas, the relative mass of trace constituents in the carrier gas is much greater than in the sample gas. The sample gas can be hot to assist desorption or a gas which reacts with trace constituents of interest to improve their detection.

Abstract: Surface ionization technique for detection of airborne particles whereby each particle is pyrolyzed on a hot surface, releasing its chemical constituents, some of which are ionized at the surface, creating a burst of ions that denote the particle's presence. The hot surface is a catalytic material deposited on an inert substrate heated by an internal heating element. Inert substrates are selected to provide mechanical strength, reduce microphonic noise and make a large catalytic surface area achievable, and hence permit high sensitivity while employing reduced quantities of catalytic materials. By locating the heater within the substrate, its electrical parameters are such that the heater power supply can be simplified. The pulses during "on" parts of the "on-off" cycles are filtered out and not counted. In one embodiment the hot sensor surface is biased to a high voltage by a high bias resistor and is coupled to a pulse-counting preamplifier through a capacitor.

Abstract: Methods and apparatus for introduction of sample from a flowing stream into mass spectrometers or other analyzing apparatus for analytical and process stream analysis of the sample. The apparatus generates an aerosol during the decompression of a gas, liquid or supercritical fluid stream. The aerosol's properties are dependent upon mass flow, pressure, temperature, solubility of sample, and the physical dimensions of the aerosol generating device. Upon aerosol generation, a less volatile sample in the form of condensed particles is separated from the gaseous components by accelerating the aerosol through a nozzle restrictor and utilizing momentum differences between solute particles and carrier gas molecules to obtain high solute enrichments at various particles or gas-phase detectors. The device functions primarily as an interface between a supercritical fluid chromatograph and the mass spectrometer.

Abstract: Methods and apparatus for liquid sample introduction into chemical detectors that require the sample to be transformed from a flowing stream into either gaseous or particulate states. The effluent from either a process stream or a liquid chromatograph is nebulized by combined thermal and penumatic processes within an inner fused silicon capillary tube heated by conduction through a relatively conductive sheathing gas such as helium or hydrogen from a surrounding electrical resistance heated outer capillary tube composed of a pure metal having a comparatively high linear relationship between temperature and electrical resistance to provide a uniform conduction of heat energy to the inner tube to form a well-collimated, partially or completely desolvated aerosol, with the less volatile solute components of the sample stream remaining in the particulate state.

Abstract: Methods and apparatus for improving the performance of triple quadrupole tandem mass spectrometers consisting of constructing the collision cell surrounding the second quadrupole structure, into which collision gas is admitted, with end plates composed of leaky dielectric material which appear to radio-frequency electric fields as a dielectric and to dc electric fields as a conductor. The result is that the rf fringe fields extend farther away from the ends of the poles of the first and third analyzing quadrupole mass filter than do the dc fringe fields, thus keeping the ions on stable trajectories in the regions between the analyzing quadrupoles and the end plates of the collision cell, and improving the transmission of ions. The effect is enhanced by applying the same frequency and phase of the ac voltages applied to all three quadrupole structures.