DETAILED 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 .
Continued Examination
A request for continued examination (RCE) under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant’s RCE submission filed on 07/23/2025 has been entered.
Status of Claims
A reply was filed on 07/23/2025. Applicant’s amendments to the drawings, specification, and claims have been entered. Claims 1 and 3-21 are pending in the application with claims 13-21 withdrawn. Claims 1 and 3-12 are examined herein.
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 Rejections - 35 USC § 112(b)
Claims 3-5 and 11-12 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 3 recites “wherein the irradiated plated target comprises an insulation layer”. Parent claim 1 previously recites “irradiating a solid target plated with a Ga-Ni alloy to form an irradiated target”. It is unclear from the claim whether (1) the solid target is intended to comprise the insulation layer, (2) somehow by irradiating the target the target forms an insulation layer (i.e., the solid target does not comprise an insulation layer prior to being irradiated), or (3) another interpretation. Perhaps the claim should be amended to recite “wherein the solid target comprises an insulation layer”.
Claim 5 recites “wherein the acid is Hydrochloric acid (HCl), sulfuric acid, nitric acid, or a combination of other acids”. It is unclear the scope of the claims encompassed by the phrase “other acids”. Can the irradiated target be dissolved using any two or more acids? Is the claim intending to recite the acid is hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof? Examiner notes, the original disclosure only appears to provide support for the acid being hydrochloric acid ([0031], [0034]-[0035], [0037], original claim 5), sulfuric acid (original claim 5), nitric acid (original claim 5), or “a combination of other strong acids” (original claim 5) (Examiner further notes that the term “strong” would appear to be a relative term, and the specification does not provide any examples of “other strong acids” or combinations of such “other strong acids” which could be used to dissolve the target).
Claim 11 recites “collecting purified Ge-68”. It is unclear if the “purified Ge-68” is intending to refer to the “purified Germanium-68” previously recited in parent claim 1 or something else.
Claim 12 recites “wherein an isotope other than Germanium is undetectable in the purified Ge-68”. An “isotope” refers to a distinct nuclear species of a chemical element1. For example, Ge-68, Ge-70, and Ge-72 are three different isotopes of germanium2. “Germanium” refers to a chemical element and encompasses many different isotopes. It is therefore unclear if the claim is intending to recite (1) other/specific isotopes of germanium are undetectable in the purified Ge-68, (2) other chemical elements are undetectable in the purified Ge-68, or (3) something else. It is further unclear by what standards or methodologies the “isotope other than Germanium” is undetectable. For example, it is unclear what amount of an “isotope other than Germanium” would be considered “undetectable” and/or using what mechanism(s) the “isotope other than Germanium” is not detected.
Any claim not explicitly addressed above is rejected because it is dependent on a rejected base claim.
Claim Rejections - 35 USC § 103
Claims 1, 3, 5, and 11-12, as best understood, are rejected under 35 U.S.C. 103 as being unpatentable over “A New Preparation of Germanium 68” (“Loc’h”) in view of “A New Production Method for Germanium-68” (“Stevenson”).
Regarding claim 1, Loc’h (previously cited) (see FIG. 1) discloses a method for producing Gemanium-68 isotopes (p. 267: “a 68Ge preparation technique”), the method comprising:
irradiating a solid target plated with a Ga-Ni alloy (“Ga4Ni”) to form an irradiated target (pp. 267-268: “A 3 g piece of nickel is placed in a test tube with 12 g of melted gallium. After cooling the resulting heterogeneous solid is melted.... [T]he alloy is poured into a copper mould where it solidifies immediately”; p. 269: “Irradiation of gallium as Ga-4Ni represents a step forward in the preparation of 68Ge. This alloy ... remains in the solid state during irradiation”),
dissolving the irradiated target with an acid (“HNO3”) (p. 268: “The target (Ga4Ni) and target-holder (copper) are dissolved together in 250 ml cold HNO3”), and
purifying the dissolved target by distillation to produce purified Ge-68 (p. 267: “After dissolution of the target 68Ge may be separated from target gallium by distillation”).
Loc’h does not appear to disclose the solid target comprises silver.
Stevenson (previously cited) is similarly directed towards a method for producing Ge-68 isotopes (p. 3: “A viable method for producing Ge-68 on compact commercial or medical cyclotrons”) comprising irradiating a solid target plated with a Ga-Ni alloy to form an irradiated target (p. 2: “the use of an electroplated alloy of gallium and nickel”, “The TRIUMF (external) solid target system employs a silver water-cooled backing plate and electroplated materials”). Stevenson teaches the solid target may comprise silver (p. 2: “the use of an electroplated alloy of gallium and nickel”, “The TRIUMF (external) solid target system employs a silver water-cooled backing plate and electroplated materials”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date (“POSA”) to include silver in Loc’h’s target because Stevenson teaches silver as a suitable backing material for Ga-Ni alloys. Additionally, it would have been obvious to a POSA to use silver for the material of the target since it has been held to be within the general skill of a worker in the art to select known material on the basis of its suitability for the intended use as a matter of obvious design choice. See In re Leshin, 125 USPQ 416.
Regarding claim 3, Loc’h in view of Stevenson teaches the method according to claim 1. Loc’h discloses the irradiated target comprises an insulation layer (“titanium foil”) (p. 268: “A 24 µm titanium foil is placed over the front face to protect the target and seal for cooling”).
Regarding claim 5, Loc’h in view of Stevenson teaches the method according to claim 1. Loc’h discloses the acid is HNO3, i.e., nitric acid3 (p. 268: “The target (Ga4Ni) and target-holder (copper) are dissolved together in 250 ml cold HNO3”).
Regarding claim 11, Loc’h in view of Stevenson teaches the method according to claim 1. Loc’h discloses collecting the purified Ge-68 (p. 269: “a 93% recovery of the 68Ga produced”).
Regarding claim 12, Loc’h in view of Stevenson teaches the method according to claim 11. Loc’h discloses an isotope other than germanium is undetectable in the purified Ge-68 (p. 269: “a 93% recovery of the 68Ge produced and eliminates other long-lived radioelements formed at the same time.... Radiochemical contamination is negligible”).
Claims 1, 5, 7, and 10-12, as best understood, are rejected under 35 U.S.C. 103 as being unpatentable over Stevenson in view of Mirzadeh.
Regarding claim 1, Stevenson discloses a method for producing Ge-68 isotopes (p. 3: “A viable method for producing Ge-68 on compact commercial or medical cyclotrons”), the method comprising:
irradiating a solid target plated with a Ga-Ni alloy to form an irradiated target (p. 2: “the use of an electroplated alloy of gallium and nickel”, “The TRIUMF (external) solid target system employs a silver water-cooled backing plate and electroplated materials”), and
dissolving the irradiated target with an acid (p. 3: “It is important to remove the Ge-68 from the irradiated Ga-Ni by acid dissolution without dissolving the silver target backing”, “Once dissolved into the acid solution, the Ge-68 has been purified using solvent extraction”), and
purifying the dissolved target (p. 3: “Once dissolved into the acid solution, the Ge-68 has been purified using solvent extraction”, “Alternatively, standard column methods were employed to purify the Ge-68”), and
wherein the solid target comprises silver (p. 2: “the use of an electroplated alloy of gallium and nickel”, “The TRIUMF (external) solid target system employs a silver water-cooled backing plate and electroplated materials”).
Stevenson does not appear to disclose producing purified Ge-68 by distillation.
Mirzadeh is similarly directed towards a method for producing Ge-68 isotopes (p. 47: “purification procedure for carrier-free 68Ge”) comprising irradiating a Ga-containing target to form an irradiated target (p. 47: “Commercial 68Ge suppliers have employed the Oak Ridge 220-cm cyclotron for isotope production, with (p, xn) nuclear reactions on Ga targets as the synthetic method”), dissolving the irradiated Ga-containing target with an acid (“HCl”), and purifying the dissolved target (p. 47: “Ge species are equilibrated with mg quantities of stable Ge carrier and then distilled from 6M HCl”). Mirzadeh teaches the target may be purified by distillation (p. 47: “a suitable purification procedure for carrier-free 68Ge. Specifically, distillation methods were investigated”).
Mirzadeh further teaches the distillation process is standard procedure for separating germanium from acidic solutions, such as HCl solutions (p. 47: “A standard procedure for the separation of macroscopic amounts of germanium from other elements involves the distillation of Ge(IV) from HCl solutions”), and provides the advantage of sufficiently purifying Ge-68 while minimizing the burden on expensive, inefficient generator chromatographic supports (p. 47: “It is important to maintain the carrier-free status of the 68Ge for optimum chemical flexibility as well as to insure a minimum burden on the chromatographic support of the biomedical generator. That is, although suitable quantities of carrier can always be added to a carrier-free 68Ge solution if necessary, the reverse procedure can only be accomplished by utilizing an expensive and often inefficient isotope separator. Obviously, the carrier-free situation will impose a smaller loading on any ion exchange material used in a generator, and thus allow the miniaturization and satisfactory development of the column employed”; p. 49: “The purification of carrier-free 68Ge from numerous other elements by distillation from HCl medium should thus be possible. The HCl composition that appeared to best satisfy consideration of 68Ge yield, distillation efficiency, and distillate acidity was the azeotropic solution”). It would have therefore been obvious to a POSA to purify Stevenson’s target by distillation, as taught by Mirzadeh, for the benefits thereof. Thus, modification of Stevenson in order to efficiently purify Ge-68 using known procedures, as suggested by Mirzadeh, would have been obvious to a POSA.
Regarding claim 5, Stevenson in view of Mirzadeh teaches the method according to claim 1. Stevenson discloses the acid is Hydrochloric acid (HCl) or sulfuric acid (p. 3: “It is important to remove the Ge-68 from the irradiated Ga-Ni by acid dissolution.... Two which have been investigated at TRIUMF are hot HCl and dilute sulfuric acid”).
Regarding claim 7, Stevenson in view of Mirzadeh teaches the method according to claim 1. Mirzadeh teaches condensing vapor produced during the dissolving (p. 47: “A standard pyrex distillation apparatus, consisting of a 100-ml round-bottom distillation flask, condenser, and receiving vessel, was assembled. To insure the complete collection of the more-volatile Ge species, a cold trap maintained at -55°C was positioned further downstream”). Thus, Stevenson’s method, modified to include Mirzadeh’s distilling process, would have resulted in the features of claim 7.
Regarding claim 10, Stevenson in view of Mirzadeh teaches the method according to claim 7. Mirzadeh teaches the vapor is condensed at a distillation condenser (p. 47: “A standard pyrex distillation apparatus, consisting of a 100-ml round-bottom distillation flask, condenser, and receiving vessel, was assembled. To insure the complete collection of the more-volatile Ge species, a cold trap maintained at -55°C was positioned further downstream”). Thus, Stevenson’s method, modified to include Mirzadeh’s distilling process, would have resulted in the features of claim 10.
Regarding claim 11, Stevenson in view of Mirzadeh teaches the method according to claim 1. Stevenson discloses collecting the purified Ge-68 (p. 3: “Once dissolved into the acid solution, the Ge-68 has been purified using solvent extraction”; pp. 3-4: “A viable method for producing Ge-68 on compact commercial or medical cyclotrons (30 MeV) has been developed. Commonly used target technology (electroplated target materials) and chemical extraction methods produce Ge-68 in solution with a high purity”).
Regarding claim 12, Stevenson in view of Mirzadeh teaches the method according to claim 11. Stevenson discloses an isotope other than germanium is undetectable in the purified Ge-68 (pp. 3-4: “A viable method for producing Ge-68 on compact commercial or medical cyclotrons (30 MeV) has been developed. Commonly used target technology (electroplated target materials) and chemical extraction methods produce Ge-68 in solution with a high purity”).
Claims 3-4, as best understood, are rejected under 35 U.S.C. 103 as being unpatentable over Stevenson in view of Mirzadeh, as applied to claim 1 above, further in view of US Publication No. 2019/0019591 (“Uhland”).
Regarding claims 3-4, Stevenson in view of Mirzadeh teaches the method according to claim 1, but appears to be silent as to an insulation layer.
Uhland (previously cited) (see FIG. 4) is similarly directed towards a method for producing Ge-68 isotopes ([0002]) using a solid target (12, 70) plated with a Ga-Ni alloy ([0020]-[0022], [0025], [0027]). Uhland teaches the solid target may further comprise an insulation layer formed of copper ([0023]).
Uhland further teaches the copper layer provides the advantage of efficiently transferring heat away from the target ([0023]). It would have therefore been obvious to a POSA to include a copper layer, as taught by Uhland, in the modified Stevenson’s target for the cooling benefits thereof. Thus, further modification of Stevenson in order to prevent overheating of the target, as suggested by Uhland, would have been obvious to a POSA.
Claim 4, as best understood, is rejected under 35 U.S.C. 103 as being unpatentable over Loc’h in view of Stevenson further in view of Uhland.
Regarding claim 4, Loc’h in view of Stevenson teaches the method according to claim 3. Loc’h discloses the insulation layer is formed of titanium (p. 268: “A 24 µm titanium foil is placed over the front face to protect the target and seal for cooling”), rather than one of the materials recited in claim 4.
Uhland (see FIG. 4) is similarly directed towards a method for producing Ge-68 isotopes ([0002]) using a solid target (12, 70) plated with a Ga-Ni alloy ([0020]-[0022], [0025], [0027]). Uhland teaches the solid target may further comprise an insulation layer formed of copper ([0023]).
Uhland further teaches the copper layer provides the advantage of efficiently transferring heat away from the target ([0023]). It would have therefore been obvious to a POSA to replace the modified Loc’h’s titanium layer with a copper material, as taught by Uhland, for the cooling benefits thereof. Thus, further modification of Loc’h in order to prevent overheating of the target, as suggested by Uhland, would have been obvious to a POSA. Additionally, it would have been obvious to a POSA to use copper, aluminum, nickel, tungsten, silver-copper alloy, tungsten-silver alloy, rhodium, rhodium-gallium alloy, niobium, or a combination thereof for the material of the insulation layer since it has been held to be within the general skill of a worker in the art to select known material on the basis of its suitability for the intended use as a matter of obvious design choice. See In re Leshin, 125 USPQ 416.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over either of (1) Loc’h in view of Stevenson or (2) Stevenson in view of Mirzadeh, as applied to claim 1 above, further in view of “The use of selective volatilization in the separation of 68Ge from irradiated Ga targets” (“Meulen”).
Regarding claim 6, Loc’h in view of Stevenson and Stevenson in view of Mirzadeh teach the method according to claim 1, but appear to be silent as to the temperature during the dissolving step.
Meulen (previously cited) is similarly directed towards a method for producing Ge-68 isotopes (p. 727: “The cyclotron production of 68Ge”) comprising irradiating a Ga-containing target to form an irradiated target (p. 727: “The cyclotron production of 68Ge can most conveniently be performed with proton-induced reactions on Ga”) and dissolving the irradiated target with an acid (“aqua regia”, i.e., hydrochloric acid and nitric acid4) (p. 728: “An activated 8g Ga target ... was placed in the reaction vessel ... containing 50 mL aqua regia. The target material was left to react and dissolve”). Meulen teaches the dissolving step occurs at a temperature of 70 degrees C (p. 728: “increasing the volume of aqua regia required to dissolve all the Ga target material and to release the 68Ge.... To this was added 200 mL aqua regia ... while heating the solution gently to 70 °C for the reaction to take place”), which falls within the claimed range of 70 degrees C to 80 degrees C.
Meulen further teaches heating of the target and acid is necessary for the dissolution reaction to take place and to ensure complete dissolution (pp. 728-729: “The target material was left to react and dissolve for 1.5 hrs, before the solution was gently heated to 70 °C for another hour to bring the reaction to completion and to ensure that all the target material was dissolved”; p. 729: “To this was added 200 mL aqua regia ... while heating the solution gently to 70 °C for the reaction to take place”). It would have therefore been obvious to a POSA to dissolve either of the modified Loc’h ‘s target or the modified Stevenson’s target at a temperature of 70 degrees C, as taught by Meulen, in order to guarantee dissolution of the target in the acid, as suggested by Meulen. Additionally, it would have been obvious to a POSA to carry out the dissolving step at a temperature in the range of 70 degrees C to 80 degrees C since it has been held that, where the general conditions of a claim are disclosed in the prior art, discovering an optimum or workable range involves only routine skill in the art. A POSA would have been aware that a higher temperature would increase the rate and amount of dissolution, but could also result in greater volatilization of undesirable elements (see e.g., Meulen, p. 729: “using a suction pump so that Ga volatility temperatures would not be reached”). A POSA would have further been aware that a lower temperature would decrease the rate and amount of dissolution or may even be insufficient for the dissolution reactions to occur.
Claims 7 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Loc’h in view of Stevenson, as applied to claim 1 above, further in view of “Studies of the Chemical Behavior of Carrier-Free Ge-68 Purification by Distillation from Acidic Chloride Solutions” (“Mirzadeh”).
Regarding claim 7, Loc’h in view of Stevenson teaches the method according to claim 1, but appears to be silent as to the specific details of the dissolving and distillation processes.
Mirzadeh (previously cited) is similarly directed towards a method for producing Ge-68 isotopes (p. 47: “purification procedure for carrier-free 68Ge”) comprising irradiating a Ga-containing target to form an irradiated target (p. 47: “Commercial 68Ge suppliers have employed the Oak Ridge 220-cm cyclotron for isotope production, with (p, xn) nuclear reactions on Ga targets as the synthetic method”), dissolving the irradiated target with an acid (“HCl”), and purifying the dissolved target (p. 47: “Ge species are equilibrated with mg quantities of stable Ge carrier and then distilled from 6M HCl”). Mirzadeh teaches the target may be purified by distillation (p. 47: “a suitable purification procedure for carrier-free 68Ge. Specifically, distillation methods were investigated”) and condensing vapor produced during the dissolving step (p. 47: “A standard pyrex distillation apparatus, consisting of a 100-ml round-bottom distillation flask, condenser, and receiving vessel, was assembled. To insure the complete collection of the more-volatile Ge species, a cold trap maintained at -55°C was positioned further downstream”). The skilled artisan would have recognized that condensing vapors is a key feature in any distillation process5.
Mirzadeh further teaches condensing the vapors allows for the collection of the desired Ge-68 (p. 47: “To insure the complete collection of the more-volatile Ge species, a cold trap maintained at -55°C was positioned further downstream”). It would have therefore been obvious to a POSA to condense the vapors produced during the modified Loc’h’s dissolving step, as taught by Mirzadeh, for the benefits thereof. Thus, further modification of Loc’h in order to amass and collect the produced Ge-68, as suggested by Mirzadeh, would have been obvious to a POSA.
Regarding claim 10, Loc’h in view of Stevenson and Mirzadeh teaches the method according to claim 7. Mirzadeh teaches the vapor is condensed at a distillation condenser (p. 47: “A standard pyrex distillation apparatus, consisting of a 100-ml round-bottom distillation flask, condenser, and receiving vessel, was assembled. To insure the complete collection of the more-volatile Ge species, a cold trap maintained at -55°C was positioned further downstream”). Thus, Loc’h’s method, modified to include Stevenson’s silver target material and Mirzadeh’s distilling process, would have resulted in the features of claim 10.
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over either of (1) Loc’h in view of Stevenson and Meulen or (2) Stevenson in view of Mirzadeh and Meulen, as applied to claim 1 above, further in view of “Production of high specific activity of 68Ge at Brookhaven National Laboratory” (“Meinkin”).
Regarding claims 8-9, Loc’h in view of Stevenson and Meulen and Stevenson in view of Mirzadeh and Meulen teach the method according to claim 1, but appear to be silent as to the temperature after the dissolving step.
Meinkin (previously cited) is similarly directed towards a method for producing Ge-68 isotopes (p. 553: “Germanium-68 is produced by irradiating natGa targets”) comprising irradiating a Ga-containing target to form an irradiated target (p. 553: “Germanium-68 is produced by irradiating natGa targets. The target is placed at the back of the target array”), dissolving the irradiated target with an acid (“HCl”) (p. 554: “A solution of 6 ml of 4N HCl and 2 ml of 30% H2O2 is added to the beaker, gently stirred, and 68Ge is extracted from the gallium in the form of the tetrachloride, GeCl4”), and purifying the dissolved target by distillation to produce purified Ge-68 (p. 555: “One method was based on a distillation procedure use to recover 68Ge”). Meinkin teaches that, after the dissolution step, the temperature is increased to 110 degrees C (p. 555: “Separating germanium as its volatile tetrachloride by distillation from 6-12N HCl is a classic purification method.... 200 µg of stable germanium was added to a 6N HCl solution and heated to 110 °C to achieve distillation”), which approaches the claimed range of 90 degrees C to 100 degrees C.
Meinkin further suggests heating of the target is necessary for the distillation reaction to take place (p. 555: “heated to 110 °C to achieve distillation”). It would have been obvious to a POSA to increase the temperature in either of the modified Loc’h’s method or the modified Stevenson’s method after the dissolving step to a temperature of between 90 degrees C to 100 degrees C since it has been held that, where the general conditions of a claim are disclosed in the prior art, discovering an optimum or workable range involves only routine skill in the art. A POSA would have been aware that a minimum temperature would be required in order to achieve distillation, but a temperature that is too high would result in the volatilization of other, undesirable elements which would reduce the purity of the collected Ge-68 (see e.g., Meulen, p. 729: “using a suction pump so that Ga volatility temperatures would not be reached”).
Response to Arguments
Applicant’s amendments to the drawings overcome the prior drawing objections.
Applicant’s amendments to the claims overcome some, but not all, of the prior 35 U.S.C. 112(b) rejections. Additionally, upon further consideration, additional 35 U.S.C. 112(b) rejections have been made as discussed above.
Applicant argues “Stevenson teaches away from the claimed invention as Stevenson specifically requires chemical extraction” (Remarks, p. 9) and “Stevenson is not properly combinable with Mirzadeh as Mirzadeh takes an opposite approach than what is taught by Stevenson” (Remarks, p. 10).
Stevenson discloses the “chemical extraction” involves “[c]hemical extraction by dissolution in various solvents” (Abstract). Stevenson’s “chemical extraction” step is mapped to the “dissolving” step in claim 1 (see paragraph 17 above). Thus, the applied combination of Stevenson and Mirzadeh in the prior Office action and above does not exclude or remove the “chemical extraction” step disclosed by Stevenson.
Additionally, a prior art reference “teaches away” from a combination if the proposed modification would render the prior art invention being modified unsatisfactory for its intended purpose. Thus, the pertinent question is whether modifying Stevenson’s method to include a distillation step to produce purified Ge-68, as taught by Mirzadeh, would render Stevenson’s method unsatisfactory for its intended purpose. There is nothing to suggest that such a modification would have resulted in an inoperable method or a change to the principle of operation of Stevenson. The intended purpose of Stevenson is to produce Ge-68 (Abstract). There is no rational, technical reasoning that purifying Ge-68 by distillation, as taught by Mirzadeh would destroy this feature of Stevenson’s method. Moreover, there is no portion of Stevenson that would prevent a skilled artisan from purifying Ge-68 by distillation, as taught by Mirzadeh, nor is there any disclosure in Stevenson criticizing, discrediting, or otherwise discouraging such a modification.
The Applied References
For Applicant’s benefit, portions of the applied reference(s) have been cited (as examples) to aid in the review of the rejection(s). While every attempt has been made to be thorough and consistent within the rejection, it is noted that the prior art must be considered in its entirety by Applicant, including any disclosures that may teach away from the claims. See MPEP 2141.02(VI).
Interview Information
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, Applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
Contact Information
Examiner Jinney Kil can be reached at (571) 272-3191, on Monday-Thursday from 7:30AM-5:30PM ET. Supervisor Jack Keith (SPE) can be reached at (571) 272-6878.
/JINNEY KIL/Examiner, Art Unit 3646
1 https://en.wikipedia.org/wiki/Isotope
2 https://en.wikipedia.org/wiki/Isotopes_of_germanium
3 https://pubchem.ncbi.nlm.nih.gov/compound/Nitric-Acid
4 https://en.wikipedia.org/wiki/Aqua_regia
5 https://en.wikipedia.org/wiki/Distillation