# US 6,720,431 B2 · Methods and apparatus for separating and detecting specific polyhalogenated diaromatic hydrocarbons > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,720,431 B2 - Document ID: US6720431B2 - Status: Granted - Kind: B2 - Application number: 09/872,758 - Filed: 2001-06-01 - Published: 2002-03-21 - Granted: 2004-04-13 - Earliest claimed: 2000-06-02 - Assignees: Xenobiotic Detection Systems International, Inc. - Inventors: Michael D. Chu; George C. Clark - Web page: https://patentgrep.com/patent/US6720431B2 ## CPC - B01D 15/08: Selective adsorption, e.g. chromatography - B01D 15/267: {using neutral sorbents, e.g. activated carbon or diatomaceous earth} - B01D 53/02: by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} - B01D 53/04: with stationary adsorbents {(B01D53/025 takes precedence)} - B01D 53/30: Controlling by gas-analysis apparatus (regulating non electrical variables in general G05D) - B01D 53/68: Halogens or halogen compounds - B01J 20/14: Diatomaceous earth - B01J 20/20: comprising free carbon; comprising carbon obtained by carbonising processes - C10G 21/006: {of waste oils, e.g. PCB's containing oils} - C10G 25/006: {of waste oils, e.g. PCB's containing oils} - B01D 2253/102: Carbon - B01D 2253/106: Silica or silicates - B01D 2256/24: Hydrocarbons - B01D 2257/206: Organic halogen compounds - B01J 2220/54: Sorbents specially adapted for analytical or investigative chromatography - G01N 1/405: {by adsorption or absorption} - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Sample processing methods that utilize a graphitised carbon matrix are useful for determining the relative amounts polyhalogenated biphenyls (PHBs), polyhalogenated dibenzofurans (PHDFs), and polyhalogenated dibenzo-p-dioxins (PHDDs) in a mixture of polyhalogenated diaromatic hydrocarbons (PHDHs). The methods are particularly useful when used in conjunction with cell-based assays for determining the toxicity of PHDH compounds. ## Claims ### Claim 1 A method of separating polyhalogenated biphenyl compounds (PHBs), polyhalogenated dibenzofurans (PHDFs) and polyhalogenated dibenzo-p-dioxins (PHDDs) from a mixture of polyhalogenated diaromatic hydrocarbons, comprising: extracting a sample with an organic solvent to produce a first extracted sample comprising polyhalogenated diaromatic hydrocarbons; contacting said first extracted sample with an adsorption matrix comprising activated carbon and diatomaceous earth, wherein said activated carbon has been heated prior to contact with the first extracted sample, and wherein PHB, PHDD and PHDF compounds adsorb onto the matrix; eluting the PHB compounds from the matrix to produce a PHB fraction; and eluting the PHDD and PHDF compounds from the matrix to produce a PHDD/PHDF fraction. ### Claim 2 (depends on 1) The method of claim 1, wherein the mixture of polyhalogenated diaromatic hydrocarbons comprises polychlorinated diaromatic hydrocarbons. ### Claim 3 (depends on 1) The method of claim 1, wherein the mixture of polyhalogenated diaromatic hydrocarbons comprises polybrominated diaromatic hydrocarbons. ### Claim 4 (depends on 1) The method of claim 1, wherein the mixture of polyhalogenated diaromatic hydrocarbons comprises mixed brominated/chlorinated diaromatic hydrocarbons. ### Claim 5 (depends on 1) The method of claim 1, wherein the PHB fraction comprises polybrominated biphenyl compounds (PBBs). ### Claim 6 (depends on 1) The method of claim 1, wherein the PHB fraction comprises polychlorinated biphenyl compounds (PCBs). ### Claim 7 (depends on 1) The method of claim 1, wherein the PHDD/PHDF fraction comprises polybrominated dibenzofurans (PBDFs). ### Claim 8 (depends on 1) The method of claim 1, wherein the PHDD/PHDF fraction comprises polychlorinated dibenzo-p-dioxins (PCDFs). ### Claim 9 (depends on 1) The method of claim 1, wherein the PHDD/PHDF fraction comprises polybrominated dibenzofurans (PBDFs). ### Claim 10 (depends on 1) The method of claim 1, wherein the PHDD/PHDF fraction comprises polychlorinated dibenzo-p-dioxins (PCDFs). ### Claim 11 (depends on 1) The method of claim 1, wherein the first extracted sample is purified by separating the sample on a matrix comprising sodium sulfate. ### Claim 12 (depends on 1) The method of claim 1, wherein the first extracted sample is further purified by separating the first extracted sample on a column comprising silica gel. ### Claim 13 (depends on 12) The method of claim 12, wherein the column comprising silica gel is treated with sulfuric acid prior to purifying the first extracted sample. ### Claim 14 (depends on 1) The method of claim 1, wherein the activated carbon is graphitized carbon. ### Claim 15 (depends on 1) The method of claim 1, wherein the PHDD/ PHDF fraction comprises one or more of a compound selected from the group consisting of 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, and their isomers. ### Claim 16 (depends on 1) The method of claim 1, wherein the sample is a liquid sample. ### Claim 17 (depends on 1) The method of claim 1 wherein the sample is a solid sample. ### Claim 18 (depends on 1) The method of claim 1 wherein the sample is a gaseous sample. ### Claim 19 (depends on 1) The method of claim 1, wherein the sample is selected from the group consisting of soil samples and ash samples. ### Claim 20 (depends on 1) The method of claim 1, further comprising determining the toxicity of the PHB fraction. ### Claim 21 (depends on 20) The method of claim 20, wherein the toxicity is determined by a cell-based assay. ### Claim 22 (depends on 21) The method of claim 21, wherein the cell based assay comprises measuring the expression of luciferase in cell line ATCC CRL-12286 in response to the concentration of PHB in the PHB fraction. ### Claim 23 (depends on 1) The method of claim 1, further comprising determining the toxicity of the PHDD/PHDF fraction. ### Claim 24 (depends on 23) The method of claim 23, wherein the toxicity is determined by a cell-based assay. ### Claim 25 (depends on 24) The method of claim 24, wherein the cell based assay comprises measuring the expression of luciferase in cell line ATCC CRL-12286 in response to the concentration of PHDD/PHDF compounds in the PHDD/PHDF fraction. ### Claim 26 A method of separating polychlorinated biphenyl compounds (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dibenzo-p-dioxins (PCDDs) from a mixture of polychlorinated diaromatic hydrocarbons, comprising: extracting a sample with an organic solvent to produce a first extracted sample comprising polychlorinated diaromatic hydrocarbons; contacting said first extracted sample with an adsorption matrix comprising activated carbon and diatomaceous earth, wherein said activated carbon has been heated prior to contact with the first extracted sample, and wherein PCB, PCDD and PCDF compounds adsorb onto the matrix; eluting the PCB compounds from the matrix to produce a PCB fraction; and eluting the PCDD and PCDF compounds from the matrix to produce a PCDD/PCDF fraction. ### Claim 27 (depends on 26) The method of claim 26, wherein the first extracted sample is purified by separating the sample on a matrix comprising sodium sulfate. ### Claim 28 (depends on 26) The method of claim 26, wherein the first extracted sample is further purified by separating the first extracted sample on a column comprising silica gel. ### Claim 29 (depends on 28) The method of claim 28, wherein the column comprising silica gel is treated with sulfuric acid prior to purifying the first extracted sample. ### Claim 30 (depends on 26) The method of claim 26, wherein the activated carbon is graphitized carbon. ### Claim 31 (depends on 26) The method of claim 26, wherein the PCDD/PCDF fraction comprises one or more of a compound selected from the group consisting of 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, and their isomers. ### Claim 32 (depends on 26) The method of claim 26, wherein the sample is a liquid sample. ### Claim 33 (depends on 26) The method of claim 26, wherein the sample is a solid sample. ### Claim 34 (depends on 26) The method of claim 26 wherein the sample is a gaseous sample. ### Claim 35 (depends on 26) The method of claim 26, wherein the sample is selected from the group consisting of soil samples and ash samples. ### Claim 36 (depends on 26) The method of claim 26, further comprising determining the toxicity of the PCB fraction. ### Claim 37 (depends on 36) The method of claim 36, wherein the toxicity is determined by a cell-based assay. ### Claim 38 (depends on 37) The method of claim 37, wherein the cell based assay comprises measuring the expression of luciferase in cell line ATCC CRL-12286 in response to the concentration of PCB in the PCB fraction. ### Claim 39 (depends on 26) The method of claim 26, further comprising determining the toxicity of the PCDD/PCDF fraction. ### Claim 40 (depends on 39) The method of claim 39, wherein the toxicity is determined by a cell-based assay. ### Claim 41 (depends on 40) The method of claim 40, wherein the cell based assay comprises measuring the expression of luciferase in cell line ATCC CRL-12286 in response to the concentration of PCDD/PCDF compounds in the PCDD/PCDF fraction. ### Claim 42 A method of comparing the amount of PCBs relative to the amount of PCDDs and PCDFs in a sample comprising a mixture of polychlorinated diaromatic hydrocarbons, comprising: extracting a sample with an organic solvent to produce a first extracted sample comprising polychlorinated diaromatic hydrocarbons; contacting said first extracted sample with an adsorption matrix comprising activated carbon and diatomaceous earth, wherein said activated carbon has been heated prior to contact with the first extracted sample, and wherein PCB, PCDD and PCDF compounds adsorb onto the matrix; eluting the PCB compounds from the matrix to produce a PCB fraction; determining the amount of PCBs present in the PCB fraction; eluting the PCDD and PCDF compounds from the matrix to produce a PCDD/PCDF fraction; determining the amount of PCDDs and PCDFs present in the PCDD/PCDF fraction; and then comparing the amount of PCBs in the PCB fraction with the amount of PCDDs and PCDFs present in the PCDD/PCDF fraction. ### Claim 43 (depends on 42) The method of claim 42, wherein the extracting of the sample is carried out by separating the sample on a matrix comprising sodium sulfate. ### Claim 44 (depends on 42) The method of claim 42, further comprising purifying the first extracted sample by separating the sample on a column comprising silica gel. ### Claim 45 (depends on 42) The method of claim 42, wherein the column is treated with sulfuric acid. ### Claim 46 (depends on 42) The method of claim 42, wherein the activated carbon is graphitized carbon. ### Claim 47 (depends on 42) The method of claim 42, wherein the sample is a liquid sample. ### Claim 48 (depends on 42) The method of claim 42, wherein the sample is a solid sample. ### Claim 49 (depends on 42) The method of claim 42, wherein the sample is a gaseous sample. ### Claim 50 (depends on 42) The method of claim 42, wherein the sample is selected from the group consisting of soil samples and ash samples. ### Claim 51 (depends on 42) The method of claim 42, wherein the PCDD/PCDF fraction comprises one or more of a compound selected from the group consisting of 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, and their isomers. ### Claim 52 (depends on 42) The method of claim 42, wherein the amount of PCBs present in the PCB fraction is determined by high resolution gas chromatography mass spectroscopy. ### Claim 53 (depends on 42) The method of claim 42, wherein the amount of PCDD and PCDF compounds present in the PCDD/PCDF fraction is determined by high resolution gas chromatography mass spectroscopy. ### Claim 54 A method of separating polychlorinated biphenyl compounds (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dibenzo-p-dioxins (PCDDs) from a mixture of polychlorinated diaromatic hydrocarbons, comprising: extracting a sample with an organic solvent to produce a first extracted sample comprising polychlorinated diaromatic hydrocarbons; purifying the first extracted sample by separating the first extracted sample on a purification matrix comprising sodium sulfate; further purifying the first extracted sample by separating the first extracted sample on a column comprising silica gel to produce a purified first extracted sample, wherein the column comprising silica gel is treated with sulfuric acid prior to purifying the first extracted sample; contacting said first extracted sample with an adsorption matrix comprising activated carbon and diatomaceous earth, wherein said activated carbon has been heated prior to contact with the first extracted sample, and wherein PCB, PCDD and PCDF compounds adsorb onto the matrix; eluting the PCB compounds from the adsorption matrix to produce a PCB fraction; and eluting the PCDD and PCDF compounds from the adsorption matrix to produce a PCDD/PCDF fraction. ### Claim 55 (depends on 54) The method of claim 54, wherein the activated carbon is AX-21. ### Claim 56 (depends on 55) The method of claim 55, wherein the AX-21 is heated prior to contacting the first extracted sample. ### Claim 57 (depends on 54) The method of claim 54, wherein the activated carbon is GRAFOIL® grade TG-407 flexible graphite powder. ### Claim 58 (depends on 1) The process of claim 1, wherein the activated carbon is an activated carbon molecular sieve. ### Claim 59 (depends on 1) The process of claim 1, wherein said activated carbon was heated to a temperature of at least about 100° C. ### Claim 60 (depends on 1) The process of claim 1, wherein said activated carbon was heated to a temperature of about 200° C. to about 250° C. ### Claim 61 (depends on 1) The process of claim 1, wherein said activated carbon was heated for a time of at least about one hour. ### Claim 62 (depends on 1) The process of claim 1, wherein said activated carbon was heated for a time of at least about one day. ### Claim 63 (depends on 1) The process of claim 1, wherein said activated carbon was heated for a time of at least about one week. ### Claim 64 (depends on 1) The process of claim 1, wherein said activated carbon was heated for a time of at least about thirty days. ### Claim 65 (depends on 26) The process of claim 26, wherein the activated carbon is an activated carbon molecular sieve. ### Claim 66 (depends on 26) The process of claim 26, wherein said activated carbon was heated to a temperature of at least about 100° C. ### Claim 67 (depends on 26) The process of claim 26, wherein said activated carbon was heated to a temperature of about 200° C. to about 250° C. ### Claim 68 (depends on 26) The process of claim 26, wherein said activated carbon was heated for a time of at least about one hour. ### Claim 69 (depends on 26) The process of claim 26, wherein said activated carbon was heated for a time of at least about one day. ### Claim 70 (depends on 26) The process of claim 26, wherein said activated carbon was heated for a time of at least about one week. ### Claim 71 (depends on 26) The process of claim 26, wherein said activated carbon was heated for a time of at least about thirty days. ### Claim 72 (depends on 42) The process of claim 42, wherein the activated carbon is an activated carbon molecular sieve. ### Claim 73 (depends on 42) The process of claim 42, wherein said activated carbon was heated to a temperature of at least about 100° C. ### Claim 74 (depends on 42) The process of claim 42, wherein said activated carbon was heated to a temperature of about 200° C. to about 250° C. ### Claim 75 (depends on 42) The process of claim 42, wherein said activated carbon was heated for a time of at least about one hour. ### Claim 76 (depends on 42) The process of claim 42, wherein said activated carbon was heated for a time of at least about one day. ### Claim 77 (depends on 42) The process of claim 42, wherein said activated carbon was heated for a time of at least about one week. ### Claim 78 (depends on 42) The process of claim 42, wherein said activated carbon was heated for a time of at least about thirty days. ### Claim 79 (depends on 54) The process of claim 54, wherein the activated carbon is an activated carbon molecular sieve. ### Claim 80 (depends on 54) The process of claim 54, wherein said activated carbon was heated to a temperature of at least about 100° C. ### Claim 81 (depends on 54) The process of claim 54, wherein said activated carbon was heated to a temperature of about 200° C. to about 250° C. ### Claim 82 (depends on 54) The process of claim 54, wherein said activated carbon was heated for a time of at least about one hour. ### Claim 83 (depends on 54) The process of claim 54, wherein said activated carbon was heated for a time of at least about one day. ### Claim 84 (depends on 54) The process of claim 54, wherein said activated carbon was heated for a time of at least about one week. ### Claim 85 (depends on 54) The process of claim 54, wherein said activated carbon was heated for at least thirty days.