Abstract: The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection.

Abstract: Increasing signal to noise ratio in optical spectra obtained by spectrophotometers. An interferometer introduces interference effects into a source light beam. A dual beam configuration splits the source beam having the interference effects into a reference beam and a sample beam. The reference beam interacts with a reference substance and is detected by a reference detector. The sample beam interacts with a sample substance and is detected by a sample detector. An optical spectra of the sample is based on the difference between the detected reference beam and the detected sample beam.

Abstract: A focused droplet nebulizer of the invention produces substantially uniform droplets of a predetermined size. Droplets are pushed out through a small outlet orifice by the contraction of a chamber. The droplets can be carried on a substantially non-divergent path in a drift tube. A piezo membrane micro pump acts in response to an electrical control signal to force a droplet out of the outlet orifice. The nebulizer can operate at frequencies permitting a stream of individual droplets of the predetermined size to be sent along the substantially non-divergent path in the drift tube in a preferred embodiment ELSD device.

Abstract: The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection.

Abstract: The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection.

Abstract: The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection.

Abstract: The invention concerns measurements in which light interacts with matter to generate light intensity changes, and spectrophotometer devices of the invention provide ultrasensitive measurements. Light source noise in these measurements can be reduced in accordance with the invention. Exemplary embodiments of the invention use sealed housings lacking an internal light source. In some embodiments a substantially solid thermally conductive housing is used. Other embodiments include particular reflection based sample and reference cells. One embodiment includes a prism including an interaction surface, a detector, a lens that focuses a prism beam output onto the detector, and a closed interaction volume for delivering gas or liquid to the interaction surface. Another embodiment replaces a prism with a reflective surface. Another embodiment replaces a prism with a scattering matte surface.

Abstract: The invention concerns improvements in spectrophotometry. Aspects of the invention may be used independently or together to increase the sensitivity of spectrophotometry. One aspect of the invention is a spectrophotometer detection circuit. In this aspect of the invention, currents attributable to reference and sample beams are cancelled in the current mode. The detection circuit produces a first voltage proportional to the difference in currents and a second voltage proportional to one of the reference or sample beams. Both voltages are available to allow simultaneous measurement and analysis. Another aspect of the invention concerns thermal stability. According to the invention, thermal conductivity is established among the housing and optical system components to promote equilibrium. Another preferred embodiment has a unitary solid metal housing with a hollowed portion defined to mount and place optical system components.

Abstract: The invention concerns improvements in spectrophotometry. Aspects of the invention may be used independently or together to increase the sensitivity of spectrophotometry. One aspect of the invention is a spectrophotometer detection circuit. In this aspect of the invention, currents attributable to reference and sample beams are cancelled in the current mode. The detection circuit produces a first voltage proportional to the difference in currents and a second voltage proportional to one of the reference or sample beams. Both voltages are available to allow simultaneous measurement and analysis. Another aspect of the invention concerns thermal stability. According to the invention, thermal conductivity is established among the housing and optical system components to promote equilibrium. Another preferred embodiment has a unitary solid metal housing with a hollowed portion defined to mount and place optical system components.

Abstract: Process for the regeneration of an activated carbon or activated coke product comprising loading the activated product into a reaction vessel having two ends, initiating a flame front at one end of the vessel, introducing an oxidant to the other end of the vessel, and allowing the flame front to move through the activated product toward the end through which the oxidant is introduced.

Abstract: Process for the treatment of a hazardous material containing a thermochemically destructible component comprising contacting the material with a carbon char, thereafter loading the carbon char into a reaction vessel having two ends, initiating a flame front at one end of the loaded vessel, introducing an oxidant to the other end of the vessel, and allowing the flame front to move through the carbon char in the direction of the end through which the oxidant is introduced and away from the end at which the flame front was initiated.