Method and apparatus for sample analysis

• US 7,257,987 B2
• Filed: 02/18/2004
• Issued: 08/21/2007
• Est. Priority Date: 01/25/2000
• Status: Expired due to Fees

• Current Assignee: Oregon State University (Oregon University System), State Of Oregon Acting By And Through The State Board Of Higher Education On Behalf Of Portland State University
• Original Assignee: State Of Oregon Acting By And Through The State Board Of Higher Education On Behalf Of Portland State University
• Inventors: O'Brien, Robert J., Smith, Thomas R.
• Primary Examiner(s): Cygan; Michael
• Application Number:
  US10/546,111
• Publication Number:
  US 20060144126A1
• Time in Patent Office: 1,280 Days
• Field of Search: 73/234.2, 73/232.2, 73/232.7, 73/233.5, 73/234.1
• US Class Current: 73/23.41
• CPC Class Codes: G01N 1/2202 involving separation of sample components during sampling
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2030/025 Gas chromatography
• CPC Class Codes: G01N 2030/324 speed, flow rate
• CPC Class Codes: G01N 2030/685 flame photometry
• CPC Class Codes: G01N 21/3518 Devices using gas filter correlation techniques; Devices using gas pressure modulation techniques
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence
• CPC Class Codes: G01N 30/32 of pressure or speed G01N30/36 takes precedence

Abstract

Methods and systems for analyzing samples, such as gas samples, are described. One method comprises providing a gas sample, increasing pressure applied to the gas sample to compress the sample to a smaller volume and provide a pneumatically focused gas sample, and analyzing the pneumatically focused gas sample using any of a variety of analytical techniques. Also disclosed are systems for gas analysis, including systems for analysis of pneumatically focused, and thereby concentrated, gas samples and for analysis of particulate matter in gas samples. Analytical systems constructed within personal computer cases also are disclosed.

Claims

1. A system for concentration and analysis of a gaseous sample, comprising:

a piston for compressing the sample from a first volume to a second volume, the second volume being smaller than the first volume;

a separatory column fluidly connected to and downstream of the piston;

an inline pressure-increasing valve downstream of the separatory column which increases system pressure to pneumatically focus the gaseous sample and reduce flow rate through the system as the piston is used to compress the sample; and

a detector for detecting analytes within the sample.

2. The system of claim 1, wherein the detector is a flame-ionization detector.

3. The system of claim 1 further comprising a piston inlet assembly.

4. The system of claim 1, wherein the system is contained in a computer case.

6. The system of claim 1, further comprising a valve arrangement downstream of the separatory column which closes a high flow channel during piston compression, thereby forcing flow through a low flow channel, and opens when the sample is compressed to the second volume, thereby allowing flow to revert to the high flow channel.

5. A method for separating and analyzing components of a gas sample, comprising:

pressurizing the gas sample in a piston to provide a pneumatically focused sample at a first pressure, the first pressure being greater than a second pressure used to separate the components of the gas sample;

introducing the pneumatically focused gas sample into a separatory column at the first pressure;

reducing the pressure in the separatory column to the second pressure;

separating the components of the gas sample at the second pressure; and

detecting the separated components of the gas sample.