DETAILED ACTION
The amendment filed on 10/10/2025 has been entered and fully considered. Claims 21-38 are pending. Claims 33-38 have been withdrawn from consideration. Claims 21-32 are considered on merits, of which claim 21-22, 30-33 and 38 are amended.
Response to Amendment
In response to amendment, the examiner maintains rejection over the prior art established in the previous Office action.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 21-25, 27, 29 and 31 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Schoell et al. (Org. Geochem. 1983, IDS) (Schoell).
Regarding claim 21, Schoell teaches a method for preparing a gaseous carbon and/or oxygen isotope working standard (abstract), the method comprising:
providing a solid or liquid carbon-containing material exhibiting a carbon isotope ratio (NBS21);
providing oxygen gas or a gas mixture comprising oxygen gas, wherein said gas or gas mixture exhibits an oxygen isotope ratio (pure oxygen);
determining, before oxidation of the solid or liquid carbon-containing material, said carbon isotope ratio in the solid or liquid carbon-containing material and/or determining said oxygen isotope ratio in the oxygen gas or the gas mixture comprising oxygen (page 3, par 1);
bringing the solid or liquid carbon-containing material in contact with the oxygen gas or the gas mixture comprising oxygen gas at elevated temperature (900˚C) to oxidize at least a part of the solid or liquid carbon-containing material to carbon dioxide to obtain the gaseous carbon and/or oxygen isotope working standard in the form of carbon dioxide (page 6, par 3).
Schoell expressly discloses:
preparing CO₂ gas by oxidizing solid or liquid carbon-containing materials (graphite or lubricating oil), and
using the resulting CO₂ as a stable isotope reference material for calibration and inter-laboratory comparison.
Specifically, Schoell states that the oxidation of NBS-22 oil or NBS-21 graphite produces CO₂ that is used to establish and revise calibration values on the PDB scale (Abstract; Conclusions). A material used as a calibration reference in isotope ratio analysis meets the plain meaning of “isotope working standard,” regardless of whether it is also an international standard.
Schoell repeatedly discloses that the carbon isotope ratios of NBS-21 and NBS-22 are known, measured, and calibrated prior to oxidation, and that those known values form the basis for the subsequent combustion and CO₂ comparison (Introduction; Results). The entire purpose of Schoell’s study is the comparison of CO₂ generated from oxidation against known isotope ratios of the starting materials.
Where a reference uses a known isotope ratio as an input to a process, the determination of that ratio is inherent. See MPEP § 2112. The law does not require that the determination be re-performed each time or explicitly listed as a step when the value is already established and relied upon.
Regarding claim 22, Schoell teaches that wherein said gaseous carbon and/or oxygen isotope reference is capable of acting as a reference in an isotope ratio analysis in which an isotope ratio in a sample is determined (page 3, par 1).
Regarding claim 23, Schoell teaches that wherein the solid or liquid carbon containing material is graphite (NBS 21) (page 3, par 1).
Regarding claim 24, Schoell teaches that wherein the carbon isotope ratio is a ratio of 13C to 12C (page 3, par 1).
Regarding claim 25, Schoell teaches that wherein the oxygen isotope ratio is a ratio of 18O to 16O or a ratio of 17O to 16O (known for pure oxygen) (page 6, par 3).
Regarding claim 27, Schoell teaches that wherein the solid or liquid carbon containing material is brought in contact with a gas mixture comprising at least 1% O2 (pure oxygen) (page 6, par 3).
Regarding claim 29, Schoell teaches that wherein the determining step is carried out by using optical spectroscopy or by mass spectrometry (page 5, par 1).
Regarding claim 31, Schoell teaches that wherein the obtained gaseous carbon and/or oxygen isotope working standard exhibits a determined carbon isotope ratio and/or a determined oxygen isotope ratio (page 3, par 1).
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 26 and 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schoell et al. (Org. Geochem. 1983, IDS) (Schoell).
Regarding claim 26, Schoell teaches that wherein the oxidation step is conducted in a temperature of 900 °C (page 6, par 3). It would have been obvious to one of ordinary skill in the art to optimize the temperature by routine experimentation.
Regarding claim 28, the phrase “the amount of carbon monoxide generated in the oxidation step is less than 5%” is an intended result and does not further limit the steps of the method. Thus, caries no weight in patent determination.
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schoell et al. (Org. Geochem. 1983, IDS) (Schoell) in view of Gonfiantini et al. (IAEA Technical Documents Series, 1995, IDS) (Gonfiantini) and Schlueter et al. (US 2016/0266031, IDS) (Schlueter).
Regarding claim 30, Schoell does not specifically teach that wherein at least two gaseous isotope working standards are prepared, each of said at least two gaseous isotope working standards exhibiting a different isotopic ratio; the method comprising:
providing a first solid carbon-containing material exhibiting a first ratio of 13C to 12C;
providing a second solid carbon-containing material exhibiting a second ratio of 13C to 12C, wherein the second ratio is different from the first ratio;
bringing the first solid carbon-containing material in contact with oxygen gas or a gas mixture comprising oxygen gas at elevated temperature to oxidize at least a part of the first solid carbon-containing material to carbon dioxide, to obtain a first gaseous carbon isotope working standard in the form of carbon dioxide;
bringing the second solid carbon-containing material in contact with oxygen gas or a gas mixture comprising oxygen gas at elevated temperature to oxidize at least a part of the second solid carbon-containing material to carbon dioxide, to obtain a second gaseous carbon isotope working standard in the form of carbon dioxide.
However, Gonfiantini teaches a second graphite material, such as USGS-24 exhibiting a second ratio of 13C to 12C, wherein the second ratio is different from the first ratio (Table 2).
Schlueter teaches using two references to compensate instrument drift and concentration changes between two references as long as these effects are expected to be linear or nearly linear” (par [0015]).
Thus, it would have been obvious to one of ordinary skill in the art to make a second reference with different 13C to 12C ratio, in order to use two references to compensate instrument drift.
Claim(s) 32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schoell et al. (Org. Geochem. 1983, IDS) (Schoell) in view of Schlueter et al. (US 2016/0266031, IDS) (Schlueter).
Regarding claim 32, Schoell does not specifically teach that wherein the obtained gaseous carbon and/or oxygen isotope working standard provides a stable isotope ratio to account for drift errors in an optical isotope measurement instrumentation used in an isotope ratio analysis of a sample (page 3, par 1).
However, Schlueter teaches that the obtained gaseous carbon and/or oxygen isotope reference provides a stable isotope ratio to account for drift errors (par [0015]) in an optical isotope measurement instrumentation used in an isotope ratio analysis of a sample (par [0003]).
Thus, it would have been obvious to one of ordinary skill in the art to use the obtained gaseous carbon and/or oxygen isotope reference to provide a stable isotope ratio to account for drift errors in an optical isotope measurement instrumentation used in an isotope ratio analysis of a sample, in order to obtain more accurate result.
Response to Arguments
Applicant's arguments filed 10/10/2025 have been fully considered but they are not persuasive.
Applicant argues that Schoell relates only to international standards (NBS-21 and NBS-22) and is “silent regarding working standards,” and therefore does not disclose preparing an isotope working standard.
This argument is not persuasive. Claim 21 does not require that the starting material be other than an international standard, nor does it impose any structural or procedural distinction between an “international standard” and an “isotope working standard.” The claim merely requires preparing a gaseous carbon and/or oxygen isotope working standard in the form of CO₂.
Schoell expressly discloses:
preparing CO₂ gas by oxidizing solid or liquid carbon-containing materials (graphite or lubricating oil), and
using the resulting CO₂ as a stable isotope reference material for calibration and inter-laboratory comparison.
Specifically, Schoell states that the oxidation of NBS-22 oil or NBS-21 graphite produces CO₂ that is used to establish and revise calibration values on the PDB scale (Abstract; Conclusions). A material used as a calibration reference in isotope ratio analysis meets the plain meaning of “isotope working standard,” regardless of whether it is also an international standard.
Applicant’s argument improperly attempts to read a source-based or administrative distinction into the claims that is not recited. The claims are directed to a method of preparing gaseous CO₂ with a defined isotope ratio, which Schoell plainly teaches.
Applicant argues that Schoell merely reports historical isotope values and does not disclose “determining, before oxidation,” the carbon and/or oxygen isotope ratio as a step of the claimed method.
This argument is not persuasive. First, claim 21 recites:
“determining, before oxidation … said carbon isotope ratio … and/or determining said oxygen isotope ratio …”
The claim uses “and/or,” meaning that either determination is sufficient.
Schoell repeatedly discloses that the carbon isotope ratios of NBS-21 and NBS-22 are known, measured, and calibrated prior to oxidation, and that those known values form the basis for the subsequent combustion and CO₂ comparison (Introduction; Results). The entire purpose of Schoell’s study is the comparison of CO₂ generated from oxidation against known isotope ratios of the starting materials.
Where a reference uses a known isotope ratio as an input to a process, the determination of that ratio is inherent. See MPEP § 2112. The law does not require that the determination be re-performed each time or explicitly listed as a step when the value is already established and relied upon.
Applicant further argues that Schoell is “silent on oxygen isotope ratios.”
This argument is not persuasive for at least two reasons.
Claim construction
Claim 21 requires determining the carbon isotope ratio and/or the oxygen isotope ratio. Schoell explicitly discloses carbon isotope ratio determination and use. Therefore, the claim limitation is met even if oxygen isotope ratios are not expressly emphasized.
Inherent disclosure
Schoell discloses oxidation in a stream of pure oxygen and oxidation via copper oxide at elevated temperatures (pp. 4–6). Any oxygen gas necessarily exhibits an oxygen isotope ratio. When oxygen is incorporated into CO₂ during oxidation, the resulting CO₂ inherently reflects the oxygen isotope composition of the oxygen source. Thus, the presence of an oxygen isotope ratio is inherent to Schoell’s method.
Applicant asserts that Schoell “relates to calibration of existing international standards, not a method for preparing anything.”
This argument is not persuasive. Schoell explicitly discloses methods of preparing CO₂ by:
oxidizing solid or liquid carbon-containing materials,
at elevated temperature,
in the presence of oxygen,
and collecting the resulting CO₂ gas (pp. 4–6).
That Schoell applies this method in a calibration context does not negate the disclosure of the method steps themselves. Intended use or motivation does not distinguish a method claim where the same steps are performed. See MPEP § 2111.02.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to XIAOYUN R XU, Ph. D. whose telephone number is (571)270-5560. The examiner can normally be reached M-F 8am-5pm.
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/XIAOYUN R XU, Ph.D./ Primary Examiner, Art Unit 1797