1、Designation: D5659 95 (Reapproved 2006)D5659 14Standard Test Method forChlorophenoxy Acid Herbicides in Waste Using HPLC1This standard is issued under the fixed designation D5659; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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 analysis of 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic
3、acid (2,4,5-T),and 2,4,5-trichlorophenoxypropionic acid (silvex) in liquids and solids, using high performance liquid chromatography with anultraviolet detector (HPLC/UV). This test method is applicable for a concentration range from approximately 50 to 1000 ppm. Thisrange takes into consideration t
4、he sample preparation and dilutions outlined in Section 10. Lower detection levels can be obtainedby using larger sample sizes, smaller total final volumes, or with the use of in-line or solid phase extraction, concentration, and/orcleanup.or cleanup, or combinations thereof.1.2 The chlorophenoxy he
5、rbicides may be present as a variety of salts or esters, which are converted to, analyzed, and reportedas their respective acids.1.3 This test method is applicable to liquid and solid waste and waste extract matrices including aqueous, oil, spent solvent, soil,ash, leachates, etc.1.4 This test metho
6、d may be applicable to other phenoxy acid herbicides.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of
7、 regulatorylimitations prior to use. See Section 7 and 10.3.1 for specific precautionary statements.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3478 Test Method for Chlorinated Phenoxy Acid Herbicides in Water (Withdrawn 1992)32.2 EPA Documents:Method 8150 Chlori
8、nated Herbicides, Test Methods for Evaluating Solid Waste Physical/Chemical Methods SW-846 ThirdEdition3Method 8000A Gas Chromatography, Test Methods for Evaluating Solid Waste Physical/Chemical Methods, SW-846, 3rdEdition, Final Update 13Method 555 Determination of Chlorinated Acids in Water by Hig
9、h Performance Liquid Chromatography with a PhotodiodeArray Ultraviolet Detector EPA/600/R-92/129, Methods for the Determination of Organic Compounds in Drinking Water,Supplement No. 233. Summary of Test Method3.1 The chlorophenoxy acids and esters are hydrolyzed to their respective salts by heating
10、and stirring the sample with aqueousalkali. The salts are then converted to their respective acids by the addition of HCl. The aqueous solutions of the free acids arethen analyzed using High Performance Liquid Chromatography (HPLC) using ultraviolet detection.4. Significance of Use4.1 Phenoxy acid h
11、erbicides are used extensively for weed control. Esters and salts of 2,4-D, 2,4,5-T, and Silvex have been usedfor agricultural crop and lawn care.1 This test method is under the jurisdiction of ASTM Committee D34 on Waste Management and is the direct responsibility of Subcommittee D34.02 on Discharg
12、e ofOrganic Wastes into Sanitary Sewers.Current edition approved Feb. 1, 2006Nov. 1, 2014. Published March 2006December 2014. Originally approved in 1995. Last previous edition approved in 20012006 asD5659 95(2001).(2006). DOI: 10.1520/D5659-95R06.10.1520/D5659-14.2 For referencedASTM standards, vis
13、it theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from the Superintendent of Documents, U.S. Government Printing Office, Washington, D
14、C 20402.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult p
15、rior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Interferences5.1 Organic liquids that
16、 have high percent levels of chlorinated organics and are denser than water may interfere with theextraction of Silvex. It is necessary to mix these samples with hexadecane, typically in a 1:1 ratio, before hydrolysis.5.2 Phenols, especially chlorophenols interfere with the procedure, by coeluting w
17、ith the analytes of interest.5.3 Interferences may be encountered from other organic compounds that absorb UV at the specified wavelengths.Also, closelyeluting compounds may complicate identification based solely on retention time. When these types of interferences areencountered, the analyst must r
18、ely on other sources of information for positive identification, such as the following:5.3.1 Secondary confirmation wavelengths such as 227 nm or 235 nm.5.3.2 Use of a confirmation column.5.3.3 Use of a confirmatory chromatography program such as changing the mobile phase composition or gradient.6.
19、Apparatus6.1 Analytical High-Pressure Liquid Chromatograph, capable of achieving pressures of 4000 psi and flow rates of 3 mL/min.6.2 Variable Wavelength Ultraviolet Detector, capable of monitoring at 207, 227, and 235 nm, either simultaneously orindividually.6.3 Chromatographic Column, C18 radial c
20、ompression 8 by 100 mm, 4-m particle size. Equivalent stainless steel or radialcompression columns may be used.6.4 Guard Column, C18, 4-m particle size.6.5 Injector, manual injection valve, instrument auto-sampler, equipped with a 500-L sample loop, or equivalent.6.6 Data Systems, data systems capab
21、le of controlling the HPLC system and for acquiring data may be used.6.7 Glass Vials, 16-mL capacity with TFE-fluorocarbon-lined screw caps.6.8 Microsyringes, 10, 100, and 500-L capacity.6.9 Balance, analytical, capable of accurately weighing to the nearest 0.0001 g.6.10 Pipets, Pasteur, disposable
22、glass.6.11 Pipets, disposable glass, 1-mL and 10-mL, calibrated.6.12 pH paper, wide range from 1 to 11.6.13 Hot Plate, with multiple stirring positions.6.14 Water Filtration Apparatus, used for the purification of water for HPLC use in 7.4.6.15 Water Filtration Filters, 0.22-m used in 7.4.6.16 Flask
23、s, 100-mL volumetric glass.6.17 Centrifuge.6.18 Stir Bars.6.19 Funnels, glass.6.20 Filter Papers, 15-cm hardened/ashless, fast.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the
24、 specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.4 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determin
25、ation.7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as defined byType II of Specification D1193.7.3 Acetone, pesticide quality or equivalent, used for preparing standards. Be advised that if methanol is used for preparing theacid standar
26、ds, over time the acid form of the herbicides will convert to their methyl ester form.7.4 Filtered Water with 0.5 % Phosphoric Acid, (FWPA). Add 5 mL high-purity phosphoric acid to 995-mL reagent water ina volumetric flask. Filter through a 0.22-m filter.4 Reagent Chemicals,American Chemical Society
27、 Specifications,American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by theAmerican 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
28、 Convention, Inc. (USPC), Rockville, MD.D5659 1427.5 Herbicide Reference StandardsThe following reference calibration compounds are required. Reference solutions can beprepared from the pure standard materials or purchased as certified solutions.7.5.1 2,4-D, 2,4,5-T, Silvex, 2,4-D methyl ester.7.5.2
29、 2,4,5-T methyl ester, Silvex methyl ester.7.6 Hexadecane, 99 %.7.7 Hydrochloric Acid (density 1.195 g/mL), concentrated hydrochloric acid (HCl).7.8 Methanol, pesticide quality or equivalent.7.9 Acetonitrile, pesticide quality or equivalent. Acetonitrile may be used as the mobile phase instead of me
30、thanol.7.10 Phosphoric Acid, H3PO4, 85 % o-phosphoric acid, HPLC Grade.7.11 Potassium Hydroxide 37 % Solutioncarefully add 37 g of ACS grade potassium hydroxide (KOH) pellets to 50 mL ofreagent water in a 100-mL volumetric flask. Mix by swirling the flask. Bring to volume with additional reagent wat
31、er.(WarningObserve caution when adding KOH to water. This will cause an exothermic reaction. Cooling the flask while mixingis suggested.)NOTE 1Caution: Observe caution when adding KOH to water. This will cause an exothermic reaction. Cooling the flask while mixing is suggested.8. Standard Preparatio
32、n8.1 Prepare stock standard solutions as follows. For herbicide acids and methyl esters, accurately weigh 0.100 g into a 10-mLglass volumetric flask. Bring to volume in pesticidegrade pesticide grade acetone. Larger volumes can be used at the convenienceof the analyst. If compound purity is 96 % or
33、greater, the weight can be used without correction to calculate the concentration ofthe stock standard.8.2 Transfer the stock standard solutions into TFE-fluorocarbon-sealed screw-cap vials. Store at 4C and protect from light.Stock standard solutions should be checked frequently for signs of degrada
34、tion or evaporation especially prior to being used toprepare calibration standards. Marking the meniscus level on the standard vial is recommended when monitoring for evaporation.8.3 Stock standard solutions must be replaced after one year or sooner if comparison with check standard indicates a prob
35、lem.8.4 Prepare calibration standard solutions from stock standard solutions at a minimum of 5 concentration levels for eachparameter. Transfer the appropriate volume of stock solution to a volumetric flask and dilute with FWPA. The concentration levelsshould correspond to the expected range of conc
36、entrations found in real samples or should define the working range of theHPLC/UV.Aworking range from 0.5 to 5 ppm has been found to be useful. Calibration solutions must be replaced after six months,or sooner if comparison with check standards indicates a problem. A 20 % deviation in response betwe
37、en the daily check and theinitial calibration would indicate a potential problem.9. Sample Collection, Preservation, and Handling9.1 Sample collection should be in accordance with appropriate sampling protocols.9.2 Sample extracts should be stored in glass containers. Long-term storage should be at
38、4C. For an aqueous matrix, 100 mLof sample are needed and 5 g of sample are needed for solids or organic liquids.9.3 Unused sample material, laboratory dilutions, and waste from the samples may be regulated. Consult your specialist and theregulations, or both, for guidance in the proper handling and
39、 disposal of laboratory waste.10. Procedure10.1 Sample Extraction and Hydrolysis (for Aqueous Matrices):10.1.1 Add 50 mL or 50 g of sample to a 100-mL volumetric or Erlenmeyer flask.10.1.2 Add 10 mLof 37 % KOH solution to the flask. Check the pH. If the pH is not 10 or greater, add additional KOH so
40、lution.Record the KOH solution used, in millilitres, and the final pH.10.1.3 Add a stir bar to the flask. Place the flask on a stirring hot plate and heat and mix at 70 to 90C for 2 h.10.1.4 Continue to 10.3.10.2 Sample Extraction and Hydrolysis (All Other Matrices):10.2.1 Weigh 5 g of sample into a
41、 100-mL volumetric or Erlenmeyer flask.NOTE 1Be cognizant of sample matrix type, especially for solid materials such as soils and ash. It may be necessary to crush or powder the sampleto ensure complete extraction.10.2.1.1 If the sample is a dense organic liquid for example, high PCB oils, chlorinat
42、ed solvents, and so forth, weigh 2.5 g ofsample into a 100-mL volumetric flask and add 2.5 g hexadecane. Mix by swirling the flask.NOTE 2It was determined through recovery studies that the chlorophenoxy herbicides remained in highly chlorinated organic liquids on the bottomof the volumetric flask af
43、ter hydrolysis. Mixing the sample with hexadecane brought the sample to the top of the volumetric flask and the herbicides wereD5659 143extracted into and remained in the aqueous phase after hydrolysis.10.2.1.2 Add 50 mL reagent water to the flask. Mix by swirling the flask.10.2.1.3 Add 10 mL of 37
44、% KOH solution to the flask. Check the pH. If the pH is not 10 or greater add additional KOHsolution. Record millilitres of KOH solution used and the final pH.10.2.1.4 Add a stir bar to the flask. Place the flask on a stirring hot plate and heat and mix at 70 to 90C for 2 h.10.2.1.5 For oil samples,
45、 after stirring is complete, remove stir bar and bring volumetric flask to volume with reagent water. Thewater meniscus should be at the mark. Let stand until the layers separate.10.2.1.6 Draw off and discard any oil layer that may be present on top of the water.10.2.1.7 For solid samples, filter ex
46、tract through filter paper (see 6.20) into a separate 100-mL volumetric flask. Rinse the filterpaper being careful not to exceed volume. Bring to volume with reagent water.10.2.1.8 Continue to 10.4.NOTE 3This is a good stopping point in the method if needed. Store sample extracts overnight in the re
47、frigerator.10.3 Preparation for Analysis (Aqueous Matrices):10.3.1 Add 5 mL of concentrated HCl to the volumetric flask containing the solution prepared in 10.1. Mix well.WarningAlways wear personal protective gear when adding concentrated acid to water because of the potential for heatgeneration. C
48、aution: always wear personal protective gear when adding concentrated acid to water because of the potential for heatgeneration.10.3.2 Check the pH using wide-range pH paper. The pH must be less than two before HPLC analysis.10.3.3 If the pH is not less than two, add additional HCl to the flask. Che
49、ck and record the final pH.10.3.4 Bring the volumetric flask to volume with reagent water.10.4 Preparation for Analysis (All Other Matrices):10.4.1 Add 8 mLof FWPAprepared in 7.4, 1 mLconcentrated HCl, and 1 mLof the sample extract prepared in 10.2 to a 16-mLglass vial. Shake.10.4.2 Check the pH using wide-range pH paper. The pH must be less than two before HPLC analysis.10.4.3 If the pH is not less than two, re-prepare the sample as in 10.4.1 using 7 mL FWPA and 2 mL concentrated HCl. Checkand record the final pH.10.4.4 If visible suspended solids are presen
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