Methods and apparatus for separating and detecting specific polyhalogenated diaromatic hydrocarbons
AssigneeXenobiotic Detection Systems International, Inc.
InventorsMichael D. Chu, George C. Clark
Life of this patent
Estimating the term…
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.
Claims85
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.
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.
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.
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.
Dependencies are inferred from the claim text.