Donald R Demers

US Patent:

41150635, Sep 19, 1978

Filed:

Apr 11, 1977

Appl. No.:

5/786663

Inventors:

Donald R. Demers - Nashua NH

Assignee:

Baird-Atomic, Inc. - Bedford MA

International Classification:

G01N 3322
G01N 2158

US Classification:

23230M

Abstract:

A method for determining both the inorganic and the metallo-organic salt content in an organic solvent. A salt-free polar solvent is added to and is mixed with a sample of an organic solvent to be analyzed, producing a two-phase intermediate solution. The intermediate soluton is mixed with and is dissolved in another salt-free solvent in which the polar solvent and the organic solvent are mutually soluble, producing a one-phase final solution. The total salt content (inorganic plus metallo-organic) of the final solution is determined by conventional techniques such as, flame photometry or atomic adsorption spectrometry.

US Patent:

45752419, Mar 11, 1986

Filed:

Sep 29, 1983

Appl. No.:

6/537177

Inventors:

Donald R. Demers - Nashua NH
Charly D. Allemand - Newton MA

Assignee:

Baird Corporation - Bedford MA

International Classification:

G01N 2164
G01N 2173

US Classification:

356316

Abstract:

A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma. Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors. The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

US Patent:

45912670, May 27, 1986

Filed:

Jan 16, 1985

Appl. No.:

6/691834

Inventors:

Donald R. Demers - Nashua NH
Charly D. Allemand - Newton MA

Assignee:

Baird Corporation - Bedford MA

International Classification:

G01J 3443
G01N 2164
G01N 2173

US Classification:

356316

Abstract:

A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma. Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors. The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

US Patent:

44326440, Feb 21, 1984

Filed:

Apr 16, 1981

Appl. No.:

6/254929

Inventors:

Donald R. Demers - Nashua NH
Charly D. Allemand - Newton MA

Assignee:

Baird Corporation - Bedford MA

International Classification:

G01N 2173

US Classification:

356316

Abstract:

A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma. Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors. The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

US Patent:

43008348, Nov 17, 1981

Filed:

May 22, 1980

Appl. No.:

6/152387

Inventors:

Donald R. Demers - Nashua NH
Charley D. Allemand - Newton MA

Assignee:

Baird Corporation - Bedford MA

International Classification:

G01N 2164
G01N 2173

US Classification:

356316

Abstract:

An inductively coupled plasma atomic fluorescence spectrometer (ICP-AFS) for multielement analysis of unknown samples. The ICP-AFS spectrometer comprises a plasma stream atomizing a dispersed sample and directed along a central axis, a plurality of optical stations surrounding the central axis, each including an energizing illuminator and a fluorescence detector focused at the same region of the plasma stream, and a readout system for identifying the unknown samples. Preferably, the plasma stream is controlled by inductive coupling, the energizing illuminator is a modified hollow cathode lamp, the fluorescence detector includes an interference filter, and the readout system incorporates multiplexing and intermittent modulation of the energizing illuminators.