ASTM D4281-95(2001)
(Test Method)Standard Test Method for Oil and Grease (Fluorocarbon Extractable Substances) by Gravimetric Determination
Standard Test Method for Oil and Grease (Fluorocarbon Extractable Substances) by Gravimetric Determination
SCOPE
1.1 These test methods cover the estimation of oil and grease in water and wastewater by a gravimetric determination of fluorocarbon extractable substances from an acidified sample. Also included in this estimation of oil and grease are any other compounds soluble in chlorofluorocarbon-113 and non-volatile under the conditions of test.
1.2 The following two test methods are included:SectionsTest Method A-Liquid-Liquid Extraction10-15Test Method B-Soxhlet Extraction16-23
1.3 These test methods are applicable to natural waters and domestic wastewaters. They are also suitable for most industrial wastewaters, although certain wastes may yield low results because of the presence of either excessive concentrations of natural greases or synthetic or modified compounds that are not well recovered by these test methods.
1.4 These test methods measure those groups of substance called oil and grease, whether soluble or insoluble, polar or non-polar, or biological or mineral in origin, to the extent these substances partition from the matrix into chlorofluorocarbon-113 and are not volatilized under conditions of the test. (See the Introduction and Section 3 of these test methods.)
1.5 Because these test methods include an acidification step prior to extraction, soluble metallic soaps are hydrolyzed and recovered as fatty acids in the extraction step.
1.6 These test methods were fully validated by collaborative testing in reagent Type IV water. The information on precision may not apply to other waters.
Note 1--Refer to companion procedures (Test Method D3921).
1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 12.1, 13.2, 20.1, and 20.5.
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An American National Standard
Designation:D 4281–95 (Reapproved 2001)
Standard Test Method for
Oil and Grease (Fluorocarbon Extractable Substances) by
Gravimetric Determination
This standard is issued under the fixed designation D 4281; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
In the determination of oil and grease, an absolute quantity of a specific substance is not measured.
Rather,groupsofsubstanceswithsimilarphysicalcharacteristicsaredeterminedquantitativelyonthe
basis of their common solubility in a specified fluorocarbon solvent. Oil and grease may therefore, be
said to include hydrocarbons, fatty acids, soaps, fats, waxes, oil, and any other material that is
extracted by the solvent from an acidified sample of the test. It is important that this limitation be
clearly understood. Unlike some constituents—which represent distinct chemical elements, ions,
compounds, or groups of compounds, oils and greases are defined by the method used for their
determination.
1. Scope 1.6 Thesetestmethodswerefullyvalidatedbycollaborative
testing in reagentType IVwater.The information on precision
1.1 These test methods cover the estimation of oil and
may not apply to other waters.
grease in water and wastewater by a gravimetric determination
of fluorocarbon extractable substances from an acidified
NOTE 1—Refer to companion procedures (Test Method D3921).
sample. Also included in this estimation of oil and grease are
1.7 The values stated in SI units are to be regarded as the
any other compounds soluble in chlorofluorocarbon-113 and
standard. The values given in parentheses are for information
non-volatile under the conditions of test.
only.
1.2 The following two test methods are included:
1.8 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
Sections
responsibility of the user of this standard to establish appro-
Test Method A—Liquid-Liquid Extraction 10-15
priate safety and health practices and determine the applica-
Test Method B—Soxhlet Extraction 16-23
bility of regulatory limitations prior to use. For specific hazard
1.3 These test methods are applicable to natural waters and
statements, see 12.1, 13.2, 20.1, and 20.5.
domestic wastewaters. They are also suitable for most indus-
trial wastewaters, although certain wastes may yield low
2. Referenced Documents
results because of the presence of either excessive concentra-
2.1 ASTM Standards:
tions of natural greases or synthetic or modified compounds
D 1129 Terminology Relating to Water
that are not well recovered by these test methods.
D 1192 Specification for Equipment for Sampling Water
1.4 These test methods measure those groups of substance
and Steam in Closed Conduits
called oil and grease, whether soluble or insoluble, polar or
D 1193 Specification for Reagent Water
non-polar,orbiologicalormineralinorigin,totheextentthese
D 3370 Practices for Sampling Water from Closed Con-
substances partition from the matrix into chlorofluorocarbon-
duits
113andarenotvolatilizedunderconditionsofthetest.(Seethe
D 3856 Guide for Good Laboratory Practices in Laborato-
Introduction and Section 3 of these test methods.)
riesEngagedinSamplingandAnalysisofWaterandWaste
1.5 Because these test methods include an acidification step
Water
prior to extraction, soluble metallic soaps are hydrolyzed and
recovered as fatty acids in the extraction step.
This test method is under the jurisdiction ofASTM Committee D-19 on Water
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor
Organic Substances in Water.
Current edition approved Dec. 10, 1995. Published February 1996. Originally
published as D4281–83. Last previous edition D4281–93. Annual Book of ASTM Standards, Vol 11.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4281–95 (2001)
D 3921 Test Method for Oil and Grease and Petroleum treatment processes and the receiving water. The procedures
Hydrocarbons in Water described here may fail to provide complete recovery of such
,
4 5
products.
D 4210 Practice for Interlaboratory Quality Control Proce-
6.4 Organic based boiler and cooling water chemicals such
dures and a Discussion on Reporting Low-Level Data
as polymeric dispersants and chelants, antifoams, filming and
D 5789 Practice for Writing Quality Control Specifications
3 neutralizing amines, and oxygen scavengers may be recovered
for Standard Test Methods for Organic Constituents
as oil and grease when these test methods are applied to such
waters.
3. Terminology
6.5 Low-boiling fractions are lost in the solvent-removal
3.1 Definitions—For definitions of terms used in these test
steps of the gravimetric procedures. Even lubrication oil
methods, refer to Terminology D1129.
fractions evaporate at a significant rate at the temperature
3.2 Definitions of Terms Specific to This Standard:
necessary for removal of the last traces of the extraction
solvent. Kerosine is still more volatile and gasoline cannot be
3.2.1 oil and grease—the organic matter and other mate-
rials extracted by the solvent from water and wastewater and determined with any reliability by a gravimetric method.
6.6 Suspendedsolidsmayinterferebycontributingtoemul-
measured by these test methods.
sions.
4. Summary of Test Method
7. Apparatus
4.1 In this test method, an acidified water sample is ex-
7.1 Drying Oven, 103°C.
tracted with fluorocarbon solvent in a separatory funnel.
7.2 Evaporating Flask, 250-mL capacity. A flat-bottom
4.2 In the gravimetric portion of the procedure, the fluoro-
boiling flask with standard taper fitting is recommended to
carbonsolventcontainingtheextractedmaterialsisevaporated
facilitate solvent recycling.
and the residue is determined gravimetrically.
7.3 Distillation Apparatus, water-cooled condenser, side
arm, and receiver, all of appropriate standard taper fitting.
5. Significance and Use
7.4 Separatory Funnels,2-LfunnelswithTFE-fluorocarbon
5.1 Aknowledgeofthequantityofoilandgreasepresentin stopcocks.
a waste is helpful in overcoming difficulties in wastewater 7.5 Steam Bath.
treatmentplantoperation,indeterminingplantefficiencies,and 7.6 Desiccator.
in controlling the subsequent discharge of these materials to
8. Purity of Reagents
receiving streams.
5.2 When oils and greases are discharged in wastewater or 8.1 Reagent grade chemicals shall be used in all tests.
treated effluents, they often cause surface films and shoreline Unlessotherwiseindicated,itisintendedthatallreagentsshall
deposits. conform to the specifications of the Committee on Analytical
Reagents of the American Chemical Society, where such
specifications are available. Other grades may be used,
6. Interferences
provided it is first ascertained that the reagent is of sufficiently
6.1 This test method is entirely empirical, and duplicate
high purity to permit its use without lessening the accuracy of
results can be obtained only by strict adherence to all details.
the determination.
By definition, any material recovered is called oil and grease
8.2 Purity of Water—Unlessotherwiseindicated,references
including such things as elemental sulfur and certain organic
to water shall be understood to mean Type IV reagent water
dyes.Inaddition,heavierresidualsofpetroleummaycontaina
conforming to Specification D1193.
significant portion of material insoluble in the solvent used.
6.2 The rate and time of extraction in the soxhlet apparatus
9. Sampling
must be exactly as directed because of varying solubilities of
9.1 Collect the samples in accordance with Specification
different oils and greases. In addition, the length of time
D1192 or Practices D3370, when applicable.
required for drying and cooling the extracted material cannot
9.2 Collect grab samples only directly into the sample
be varied. There may be a gradual increase in weight, presum-
bottle. Oils and greases may be lost on any sampling equip-
ably due to the absorption of oxygen, or a gradual loss of
ment used. Do not rinse the sample bottles with the sample
weight due to volatilization.
6.3 Modern industry uses a number of long-chain carbon
compounds as lubricants and emulsifiers, as well as for other
Chanin, G., E. H. Chow, R. B.Alexander, and J. F. Powers, “ScumAnalysis:A
purposes.Oftenthecompositionofthesematerialsdiffersfrom
New Solution to a Difficult Problem,” WWWEA-5,6-49-68.
that of natural oils and greases, and may render them more 5
Taras, M. J. and K. A. Blum, “Determination of Emulsifying Oil in Industrial
soluble in water or more easily emulsified than the natural Wastewater,” JWPFA-40-R404-68.
Reagent Chemicals, American Chemical Society Specifications, American
products. As a result, they behave as oils and greases in
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 11.02. MD.
D 4281–95 (2001)
NOTE 4—Frequently,solventwillextractplasticizerfromplastictubing
prior to filling as the oils may adhere to the inside of the bottle
that is used to transfer from one container to another and from shipping
and lead to high results.
container liner. Check for contamination by evaporating 180 mL of
9.3 Because a portion of the collected oils and greases may
solvent on a steam bath and weighing the residue. The solvent should
adhere to the sample bottle, analyze all of the sample collected
leavenomeasurableresiduegreaterthan0.1mg.Ifthisvalueisexceeded,
as one specimen. One-litre samples are normally specified,
distill the solvent and check the distillate for residue.
although larger or smaller samples may be taken depending on
12.2 Mark the sample bottle at the water meniscus for later
the concentration of extractables expected to be present.
determinationofsamplevolume.Pourtheacidifiedsampleinto
9.4 Leave an air space above the liquid in the sample bottle
a separatory funnel.
to facilitate handling during analysis.
12.3 Add 60 mL of fluorocarbon solvent to the sample
9.5 Collect all samples in glass bottles with nonorganic or
bottle, cap, and shake the bottle well. Pour the solvent into the
insoluble caps, or both.
separatoryfunnelandextractthesamplebyshakingvigorously
9.6 Acidify the sample to < pH 2 with HCl (1+1) or
for 2 min. Invert the separatory funnel and vent with stopcock
H SO (1+1) to maintain the integrity of the sample.
2 4
to relieve pressure buildup during the extraction. After the
NOTE 2—ForCleanWaterActpurposesonlyH SO shouldbeusedand
layers have separated, drain the solvent layer through filter
2 4
the sample should be cooled to 4°C and analyzed within 28 days.
paper held by a small funnel into the tared boiling flask. If
emulsionproblemsareanticipated,add1gNa SO tothefilter
2 4
TEST METHOD A—LIQUID-LIQUID EXTRACTION
paper cone and slowly drain the solvent through the crystals.
Add more Na SO if necessary.
10. Scope 2 4
10.1 This test method covers the estimation of oil and NOTE 5—Solvent phase separation paper helps to keep water out.
grease from 4 to 100 mg/L in water and wastewater by a
12.4 If a clear solvent layer cannot be obtained due to
gravimetric determination of fluorocarbon extractable sub-
emulsion with water, add up to 100 g of NaCl to separatory
stances from an acidified sample.
funnel.Shaketodissolvethesalt.Frequentlythiswillbreakthe
10.2 This test method is generally applicable to samples
emulsion.Iftheemulsioncannotbebroken,thistypeofsample
containing extractable substances.
must be analyzed by the Soxhlet extraction test method.
12.5 Repeat the bottle rinse and extraction with two addi-
11. Reagents and Materials
tional 60-mL portions of solvent, combining all solvent in the
11.1 Acetone ((CH ) CO), technical grade.
3 2
flask. Rinse the filter with 20 mL of solvent, into the flask.
11.2 Filter Paper, any high flow, low-retention grade, or
12.6 Proceed to 13.1.
optionally phase separating paper.
13. Procedure, Gravimetric for Test Methods A and B
11.3 Fluorocarbon Solvent (Chlorofluorocarbon-113 or
1,1,2-Trichloro-1,2,2-Trifluoroethane) mustbeshowntocon- 13.1 Evaporate the solvent from the boiling flask (12.5,
tain no significant residue on evaporation. Redistill if neces-
20.8) on a hot water bath or steam bath. (Recovering solvent
sary. using a condenser system is recommended.)
11.4 Hydrochloric Acid (HCl), sp gr 1.19.
13.2 When only a few millilitres of solvent remain (under
11.5 Sodium Bisulfate—(NaHSO ·H O). 10 mL of solvent is not recommended), leave the flask on the
4 2
11.6 Sodium Chloride (NaCl).
steam bath and draw air through the flask using vacuum for 5
11.7 Sodium Sulfate (Na SO ), anhydrous. min to remove the last traces of solvent or residual water.
2 4
11.8 Sulfuric Acid (H SO ), sp gr 1.84.
Carefullywipetheexterioroftheflaskwithalintfreeclothand
2 4
asmallamountofacetonetoremoveanywateradheringtothe
12. Procedure
flask. Warning—Wear protective gloves (polyethylene or
12.1 Tare,tothenearesttenthofamilligram,aboilingflask
similar solvent-resistant material) to prevent the acetone from
that has been dried at 103°C in an oven for 1 h and cooled in
coming in contact with the skin. Use acetone in a fume hood.
a desiccator to room temperature. Caution—Always handle
13.3 Place in a desiccator for 1 h, remove, and weigh
the flask with metal tongs or weighing gloves to avoid
immediately, to the nearest tenth of a milligram.
deposition of body oils.
13.4 Measure the original sample volume by filling the
sample bottle to the mark with water at 20°C and measure the
NOTE 3—Run a reagent and materials blank to show that they contain
volumeofwaterwithagraduatedcylinder,tothenearest5mL.
nosignificantresiduewithrespecttotheprecisionofthetestmethodatthe
level measured.
NOTE 6—Itisrecommendedthatthechlorofluorocarbon-113solventbe
recycled to reduce costs and minimize discharges to the atmosphere. To
recycle the solvent, attach a water cooled condenser with a side arm take
See Title 40, Code of Federal Regulations, Part 136 (40 CFR 136), Table 2,
off. The recovered solvent can usually be reused for this test without
Required Containers, Preservation Techniques, and Holding Times, by the U.S.
redistillation.
Environmental Protection Agency, available from Superintendent of Documents,
U.S. Government Printing Office, Washington, DC 20
...
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