Analytical method for detecting fuel markers

Patent metadata

Field	Value
Publication number	US-9759697-B2
Application number	US-201414787520-A
Country	US
Kind code	B2
Filing date	May 2, 2014
Priority date	May 2, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A gas chromatographic method for detecting a marker compound in a fuel by (a) introducing a sample of fuel into a first capillary column coated with a stationary phase based on polydimethylsiloxane and allowing the sample to flow through the first column to produce a first effluent; (b) allowing the first effluent to pass through a detector and identifying a retention time range in it which includes a retention time of the marker compound; (c) introducing only a portion of the first effluent stream which is within the retention time range into a second capillary column coated with either (i) an ionic sorbent or (ii) a polyethylene glycol, and allowing said portion to flow through the second capillary column to produce a second effluent stream; and (d) allowing the second effluent to pass through a detector; wherein the marker compound has formula Ar(R 2 ) m (OR 1 ) n and is present in the fuel at a level from 0.01 ppm to 100 ppm.

First claim

The invention claimed is:

1. A gas chromatographic method for detecting a marker compound in a petroleum hydrocarbon or a liquid biologically derived fuel; said method comprising:
(a) introducing a sample of a petroleum hydrocarbon or a liquid biologically derived fuel into a first capillary column which is an open tubular column coated with a polysiloxane stationary phase and allowing the sample to flow through the first capillary column to produce a first effluent stream; (b) allowing the first effluent stream to pass through a detector and identifying a retention time range in the first effluent stream which includes a retention time of the marker compound; (c) introducing only a portion of the first effluent stream which is within the retention time range into a second capillary column which is an open tubular column coated with either (i) an ionic sorbent or (ii) a polyethylene glycol, and allowing said portion to flow through the second capillary column to produce a second effluent stream; and (d) allowing the second effluent stream to pass through a detector;
wherein the marker compound has formula (I)

wherein R 1 is C 1 -C 12 alkyl or C 2 -C 12 alkenyl, R 2 is C 1 -C 12 alkyl or C 3 -C 12 alkenyl, m is an integer from zero to five and n is an integer from one to three; and wherein each compound of formula (I) is present in the petroleum hydrocarbon or a liquid biologically derived fuel at a level from 0.01 ppm to 100 ppm.

2. The method of claim 1 in which a portion of the first effluent stream which is not within the retention time range is diverted from the second capillary column using a non-contact switching device.

3. The method of claim 2 in which R 1 is C 4 -C 12 alkyl.

4. The method of claim 3 in which the marker compound is identified in the second effluent stream by mass spectrometry.

5. The method of claim 4 in which n is one and m is zero.

6. The method of claim 5 in which the second capillary column is coated with an ionic sorbent which is a salt of sodium, potassium or barium, or a mixture thereof.

7. The method of claim 6 in which the polysiloxane stationary phase is polydimethylsiloxane.

Assignees

• Dow Global Technologies Llc
• Rohm & Haas

Inventors

• Gras Ronda L
• Luong Jim C
• Smith Warren E

Classifications

• G01N2030/8854

  involving hydrocarbons · CPC title

• G01N2030/042

  Standards · CPC title

• G01N33/2882

  Markers · CPC title

• G01N30/88

  Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86 · CPC title

• G01N30/7233

  interfaced to liquid or supercritical fluid chromatograph (interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04) · CPC title