1、Designation: D7678 11Standard Test Method forTotal Petroleum Hydrocarbons (TPH) in Water andWastewater with Solvent Extraction using Mid-IR LaserSpectroscopy1This standard is issued under the fixed designation D7678; the number immediately following the designation indicates the year oforiginal adop
2、tion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of totalpetroleum hydrocarbons
3、 (TPH) in water, and waste water, thatare extractable from an acidified sample with a cyclic aliphatichydrocarbon (for example cyclohexane), and measured by IRabsorption in the region of 1370 -1380 cm-1(7.25 -7.30microns). Polar substances are removed by clean-up withFlorisil.1.2 The method also con
4、siders the volatile fraction ofpetroleum hydrocarbons which is lost by gravimetric methodsthat require solvent evaporation prior to weighing, as well asby solventless IR methods that require drying of the employedsolid phase material prior to measurement. Similarly, a morecomplete fraction of extrac
5、ted petroleum hydrocarbon is ac-cessible by this method as compared to GC methods that use atime window for quantification, as petroleum hydrocarbonseluting outside these windows are also quantified.1.3 This method defines oil and grease in water and waste-water as that which is extractable in the t
6、est method andmeasured by IR absorption in the region of 1370-1380 cm-1(7.25 7.30 microns).1.4 This method covers the range of 0.5 to 1000 mg/L andmay be extended to a lower or higher level by extraction of alarger or smaller sample volume collected separately.1.5 The values stated in SI units are t
7、o be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices an
8、d determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1141 Practice for the Preparation of Substitute OceanWaterD1193 Specification for Reagent WaterD1192 Guide for Equipment for Sampling Water and Steamin
9、 Closed Conduits3D2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3921 Test Method for Oil and Grease and PetroleumHydrocarbons in WaterD5847 Practice for Writing Quality Control Specific
10、ationsfor Standard Test Methods for Water AnalysisD7575 Test Method for Solvent-Free Membrane Recover-able Oil and Grease by Infrared DeterminationE168 Practices for General Techniques of Infrared Quanti-tative Analysis2.2 ISO Standards:4ISO 9377-2 Determination of Hydrocarbon Oil Index3. Terminolog
11、y3.1 Definitions:For definitions of terms used in this test method, refer toTerminology D1129 and Practice E168.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee on Methods forAnalysis of OrganicSubstances in Water.Current edit
12、ion approved Feb. 1, 2011. Published March 2011. DOI: 10.1520/D7678112For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM
13、website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100
14、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This Standard:3.2.1 Total petroleum hydrocarbons (TPH), nthe ex-tracted material which remains in the solvent after treatmentwith Na2SO4and Florisil.4. Summary of Test Method4.1 An ac
15、idified 900 mL sample of water or wastewater isextracted with 50 mL of cyclohexane. The extract is treatedwith sodium sulfate and Florisil to remove traces of water, aswell as polar substances, thereby producing a solution contain-ing nonpolar material. The nonpolar material is referred to astotal p
16、etroleum hydrocarbons (TPH) and is measured bymid-infrared laser spectroscopy.5. Significance and Use5.1 The presence and concentration of total petroleumhydrocarbons, as well as oil and grease, in domestic andindustrial wastewater is of concern to the public because of itsdeleterious aesthetic effe
17、ct and its impact on aquatic life.5.2 Regulations and standards have been established thatrequire monitoring of total petroleum hydrocarbons as well asoil and grease in water and wastewater.6. Interferences6.1 Soaps, detergents, surfactants and other materials mayform emulsions that could reduce the
18、 amount of total petro-leum hydrocarbons extracted from a sample. This test methodcontains procedures that can assist the analyst in breaking suchemulsions.6.2 Organic compounds and other materials not consideredas total petroleum hydrocarbons on the basis of chemicalstructure may be extracted, reta
19、ined in the extract after filtra-tion over Florisil and thus measured as total petroleum hydro-carbons (for example, halogenated hydrocarbons).7. Apparatus7.1 All glassware that will come in contact with the sampleshall be thoroughly cleaned, rinsed with distilled water anddried at 130 C. Prior to s
20、tarting this procedure the glasswareshall be rinsed with solvent.7.2 Cell(s), calcium fluoride, two required for double-beamoperation, one required for single-beam operation. The pathlength of the cells should be chosen for optimum signal tonoise at the measurement wavelengths. This will be 2-3 mm i
21、ncase of quantum cascade laser based spectrometers. However,longer path lengths may be appropriate should more powerfullasers become available.7.3 Mid-infrared laser spectrometer with an optical power20 mW within the spectral region of 7.25-7.30 m. Eitherdouble-beam or single-beam and capable of mak
22、ing measure-ments in the region from 7.25-7.30 m or single beaminstrument tunable from 7.14 7.30 m.57.4 Glass Wide Mouth Sample Bottle, minimum 250 mL,suggested 1 L, either with screw cap having a fluoropolymerliner or a wide-necked glass flask with a ground neck witheither glass or fluoropolymer st
23、opper. The sampling bottle shallallow direct extraction from the bottle.7.5 Micro-separator, for example see Fig. X1.1, or othersuitable device for phase separation.7.6 Clean-up columns, made from glass, with frit of sinterporosity 2, for example see Fig. X1.27.7 Glass bottle 50-100 mL with glass or
24、 fluoropolymerstopper or crimped cap with lined PTFE septum.7.8 Magnetic stirrer, with PTFE-fluorocarbon stirring bar.7.9 Volumetric flasks, glass, various (50, 100, and 200 mL).7.10 Teflon spritz bottle, one-piece wash bottle for rinsing.7.11 Volumetric pipettes, glass, various (20, 30 and 40 mL).7
25、.12 Analytical balance.7.13 Graduated glass syringes (for example Hamilton) 5 and25 L.7.14 Benchtop shaker, (optional).7.15 Glass stirring rod, (optional).7.16 A 1.00 mL serological glass pipet graduated in0.01-mL increments and a 5.00-mL serological glass pipetgraduated in 0.1-mL increments, or equ
26、ivalent (optional).8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the American Chemical Society,where such speci
27、fications are available. Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto laboratory or reagent water shall be unde
28、rstood to meanreagent water conforming to Specification D1193, Type II.8.3 Tetradecane99.0 % minimum purity, for use in cali-bration.8.4 Petroleum hydrocarbonssimilar in composition topetroleum hydrocarbons determined by this test method forpossible use as calibration material.8.5 Mineral oil type A
29、 (Diesel oil without additives) andMineral oil type B (Lubricating oil without additives)Theseoil types may be obtained from suppliers of fine chemicals, forexample Fluka (mineral oil typeA: Product No. 91975; mineraloil type B: Product No. 78473). Alternatively a readily pre-pared 1:1 (w:w) mixture
30、 of these oils may be used (forexample, BAM K010 from the German Federal Institute forMaterials Research and Testing).8.6 Florisilgrain size 150 m to 250 m (60 mesh to 100mesh), heated to 140C for 16 h and stored in a desiccators.Florisil is a trade name for a prepared diatomaceous substance,mainly
31、consisting of anhydrous magnesium silicate, availablefor example from Sigma Aldrich (Product Number 03286).Determine the cyclohexane soluble material content of theFlorisil by extracting 10 g of Florisil with 25 mL of cyclohex-ane and collect the elute in a flask. Filter and fill a calciumfluoride c
32、ell for analysis by IR. The cyclohexane solublematerial must be less than 0.5 mg/25mL.8.7 Sodium Sulfate (Na2SO4)anhydrous, granular.5For example: The ERACHECK from Eralytics GmbH has been found to meetthese specifications.D7678 1128.8 Sulfuric Acid (1+1)Slowly and carefully add 1 vol-ume of sulfuri
33、c acid (H2SO4, sp gr 1.84) to 1 volume of water,stirring and cooling the solution during addition.8.9 Hydrochloric acid, ACS, (1 + 1)Mix equal volumes ofconcentrated HCl and water.8.10 SolventCyclohexane (minimum purity 99.5%) orcyclopentane (minimum purity 98.5%)9. Hazards9.1 Normal laboratory safe
34、ty applies to this method. Ana-lysts should wear safety glasses, gloves and lab coats whenworking with acids.Analysts should review the material SafetyData Sheets (MSDS) for all reagents used in this method.Additional hazards may be presented by the particular samplebeing tested so proper care must
35、be taken.10. Sampling10.1 Collect the sample in accordance with the principlesdescribed in Practice D3370, using a glass bottle according to7.4. Weigh the dried bottle before sample collection. Prerinsethe sample bottle and cap with the solvent prior to samplecollection. Do not rinse the sample bott
36、le with the sample to beanalyzed. Do not allow the sample to overflow from the bottleduring collection. Preventing overflow may not be possible inall sampling situations, however, measures should be taken tominimize overflow at all times.10.2 A sample volume of about 900 mL is required for thistest.
37、 Weigh the bottle containing the sample to determine theactual sampled amount. Alternatively, record the sampledvolume. Use the entire sample because removing a portionwould not apportion the petroleum hydrocarbon that adheres tothe bottle surfaces. The high probability that extractable mattermay ad
38、here to sampling equipment and result in measurementsthat have a low bias precludes the collection of compositesamples for determination of total petroleum hydrocarbon.Therefore, samples must be collected as grab samples. If acomposite measurement is required, individual grab samplescollected at pre
39、scribed time intervals may be analyzed sepa-rately and the concentrations averaged. Alternatively, samplescan be collected in the field and composited in the laboratory.For example, collect three individual 300 mL samples over thecourse of a day. In the laboratory, extract each 300 mL samplewith 15
40、mL and combine the extracts in a 50 mL volumetricflask and fill up to mark with solvent prior to clean-up (13.2).10.3 Preserve the sample with a sufficient quantity ofsulfuric acid (see 8.8) or hydrochloric acid (see 8.9)toapHof2 or lower and refrigerate at 1-6 C from the time of collectionuntil ext
41、raction. The amount of acid required will be dependentupon the pH and buffer capacity of the sample at the time ofcollection. If the amount of acid required is not known, makethe pH measurement on a separate sample that will not beanalyzed. Introduction of pH paper to an actual sample orsample cap m
42、ay remove some oil from the sample. In case thebottle containing the sample can not be weighed beforeaddition of the acid, the volume of acid added to each samplecan be recorded, then subtracted from the final measuredsample amount. If the sample is to be shipped by commercialcarrier, U.S. Departmen
43、t of Transportation regulations limit thepH to a minimum (see 40CFR Part 136, Table II Footnote 3) of1.15 if H2SO4is used and 1.96 if HCl is used (see 49 CFR part172).10.4 Samples shall be extracted and analyzed within oneweek. Once extracted, the extract can be stored up to 6 monthsat a temperature
44、 between 7 and 10C.11. Preparation of Apparatus11.1 Mineral Oil A and B (1+1) for preparing the laboratorycontrol sample (LCS) to be applied as matrix spike Place 500mg of Mineral OilAand 500 mg of Mineral Oil B in a 2-10 mLglass vial with glas or fluroplolymer stopper and mix thor-oughly and store
45、at 1-6 C for a maximum period of 6 months.12. Calibration and Standardization12.1 To ensure analytical values obtained using this testmethod are valid and accurate within the confidence limits ofthe test, the instrument manufacturers instructions and thefollowing procedures must be followed when per
46、forming thetest method.NOTE 1This test method uses cyclohexane as solvent. However, othercyclic aliphatic hydrocarbons such as cyclopentane may be used insteadwith very similar figures of merit in terms of precision and dynamic range.It will be the responsibility of the user to demonstrate equivalen
47、tperformance when using solvents other than cyclohexane.NOTE 2For calibration of the instrument, standards prepared byweighing tetradecane in solvent shall be used. This is different to formertest methods (for example ASTM D3921) which allow calibration eitherwith the type of petroleum hydrocarbon t
48、hat is known to be present in thesample of water or wastewater or, alternatively, using a defined calibrationmaterial (for example, mixture of isooctane and cetane). The purpose ofdefining one calibration material is to facilitate comparability of resultsobtained by different laboratories. Tetradeca
49、ne was selected as calibrationmaterial as it best correlates with different types of petroleum hydrocar-bons including heavy crude oil and condensate. In case the concentrationof petroleum hydrocarbon in a constant matrix void of other extractables(for example process monitoring of crude oil in water) is to be determined,calibration of the instrument may be done with the type of petroleumhydrocarbon awaiting analysis. In this special case, the clean-up step maybe omitted and the extract measured directly after solvent extraction.However, measurement of
