Method for the gravimetric determination of oil and grease
AssigneeThe United States of America as represented by the Administrator of the Environmental Protection Agency
InventorFred K. Kawahara
Life of this patent
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Abstract
A non-halogenated solvent mixture for gravimetric determination of grease and oil in an aqueous or a solid matrix comprising a mixture of n-hexane and methyl tertiary-butyl ether present in a volume ratio of 80% to 20% respectively. A method of gravimetric determination of grease and oil in an aqueous or a solid matrix which comprises preparing a sample; extracting the same using this non-halogenated solvent mixture; distilling; evaporating and weighing the extraction residue.
Claims8
A method of dissolving grease and oil using a replacement solvent for 1,1,2-trichloro-1,2,2 trifluoroethane in the gravimetric determination of oil and grease in an aqueous matrix or solid matrix comprising the steps of dissolving said oil or grease using an effective amount of a solvent comprising a mixture of n-hexane and methyl tertiary-butyl ether present in a volume to volume ratio of 80% to 20% respectively to substantially dissolve said oil and grease.
A method of gravimetric determination of grease and oil in an aqueous matrix, which comprises the steps of:
- (a) preparing a sample by adding 6 N hydrochloric acid at a rate of 5 ml of acid per liter of sample so that the pH of said sample is .ltoreq.2 and storing said prepared sample at 4.degree. C.;
- (b) extracting said prepared sample by using an organic solvent mixture comprising n-hexane:methyl tertiary-butyl ether present in a volume to volume ratio of about 80% to 20% respectively;
- (c) distilling said solvent mixture extraction layer, leaving an extraction residue and residual solvent mixture;
- (d) evaporating any residual solvent mixture from said extraction residue;
- (e) removing any residual water from said extraction residue;
- (f) weighing said extraction residue at 15 minute intervals to a constant weight and
- (g) determining the extractable grease and oil content of said extraction residue.
A method of gravimetric determination of grease and oil in a solid matrix which comprises the steps of:
- (a) preparing a sample by adding concentrated HC until the pH of said sample=2;
- (b) drying said prepared sample by adding prepared MgSO.sub.4.H.sub.2 O and allowing sample to solidify;
- (c) grinding said dried solid sample to a powder form;
- (d) adding dried ground sample to an extraction thimble;
- (e) extracting said prepared sample using a Soxhlet extraction apparatus;
- (f) evaporating off said solvent mixture leaving an extracting residue and residual solvent mixture;
- (g) evaporating any residual solvent mixture from said extraction residue;
- (h) removing any residual water from said extraction residue;
- (i) weighing said extraction residue at 15 minute intervals to a constant weight;
- and
- (j) determining the extractable grease and oil content of said extraction residue.
Dependencies are inferred from the claim text.