1、Designation: E2686 09 (Reapproved 2015)Standard Test Method forVolatile Organic Compound (VOC) Solvents Absorbed/Adsorbed By Simulated Soil Impacted by PesticideEmulsifiable Concentrate (EC) Applications1This standard is issued under the fixed designation E2686; the number immediately following the
2、designation indicates the year oforiginal adoption 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 simulates
3、 the application of an emul-sion of a pesticide emulsifiable concentrate (EC) to soil withhigh organic matter (corn cob granules) and to soil with highinorganic matter (clay granules) and determines the amount ofsolvent retained by the granules, and withheld from theatmosphere, before and after expo
4、sure to 40C in a ventedoven. The granules simulate two extremes of soil composition,and the 40C exposure simulates high temperature weathering.Solvent loss from organic substrates other than corn cob mayalso be determined by repeating the 40C exposure tests withthe chosen substrate replacing corn co
5、b. The results with corncob, however, are a reference that must be reported with thealternate substrate results. The difference in solvent content ofthe granules before and after weathering is an indication of theemission of the solvent from soil impacted by emulsions orsolutions during pesticide ap
6、plications using common practicessuch as spraying and drip irrigating. Analysis of the granulesfor solvent content is by high pressure liquid chromatography(HPLC), gas chromatography (GC), or other methods testedand proven to be accurate and reproducible.NOTE 1Since it evaluates soil surface sorptio
7、n, this test method willunderestimate soil sorption from pesticide applications made below thesoil surface. Sub-soil surface treatments may include, but are not limitedto, mechanical soil injection and soil incorporation applications. In thesecases, the increased depth of the sub-soil treatments red
8、uce the soil surfaceexposure and facilitate increased levels of soil sorption.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with i
9、ts use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 Other Standards:240 CFR 51.100(s) Protection of EnvironmentRequirements for Preparatio
10、n,Adoption, and Submittal ofImplentation PlansDefinitions3. Terminology3.1 Definitions:3.1.1 absorb, va process in which one material (theabsorbent) takes in, and retains, through its pores and inter-stices the molecules of another material (the absorbate).3.1.2 adsorb, va process in which one mater
11、ial (theadsorbent) attracts to, and retains on, its surface the moleculesof another material (the adsorbate).3.1.3 emulsifiable concentrate, na single-phase liquid sys-tem having the property of forming an emulsion when mixedwith water.3.1.4 emulsifying agent, na surfactant that promotes thesuspensi
12、on of one liquid in another.3.1.5 gas or liquid chromatography, na process in whicha chemical mixture carried by a mobile liquid or gas isseparated into components as a result of different affinities ofthe components for the liquid or gas and the adsorbing mediumthrough which they pass.3.1.6 inorgan
13、ic matter, nsubstances of mineral origin thatare not characterized by primarily carbon-based structures.3.1.7 organic matter, nin soil, organic matter consists ofplant and animal material that is in the process of decompos-ing.3.1.8 tropospheric ozone, nan air pollutant formed by thesunlight catalyz
14、ed reaction between hydrocarbons and nitrogen1This test method is under the jurisdiction of ASTM Committee E35 onPesticides, Antimicrobials, and Alternative Control Agents and is the directresponsibility of Subcommittee E35.22 on Pesticide Formulations and DeliverySystems.Current edition approved Oc
15、t. 1, 2015. Published November 2015. Originallyapproved in 2009. Last previous edition approved in 2009 as E268609. DOI:10.1520/E2686-09R15.2Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.g
16、ov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1oxides present in the troposphere, the layer of the atmosphereclosest to the earths surface.3.1.9 volatile organic compound (VOC), n any compoundof carbon, excluding carbon monoxide,
17、carbon dioxide, car-bonic acid, metallic carbides or carbonates, and ammoniumcarbonate, which participates in atmospheric photochemicalreactions; excluded is a list of organic compounds which havebeen determined to have negligible photochemical reactivity(40 CFR 51.100(s).3.1.10 volatilize, vto pass
18、 off as vapor; to evaporate.4. Summary of Test Method4.1 A pesticide EC (emulsifiable concentrate) is simulatedwith a concentrate consisting only of solvent plus emulsifyingagent(s). The concentrate is then mixed with water, and theemulsion is applied to corn cob granules (organic substrate)and mont
19、morillonite clay granules (inorganic substrate), whichabsorb/adsorb the liquid.4.2 Other organic substrates, like corn stover, straw, orsphagnum peat, for example, may simulate the harvest debrisfrom some crops better than corn cob, and the test method canbe used with any of this type substrate repl
20、acing corn cob. Caremust be taken to select a substrate appropriate for the crop ofconcern, and the results with corn cob are a reference that mustbe reported with the alternate substrate results. The treatedgranules are placed in a vented 40C oven in uncapped bottles.The uncapped bottles allow for
21、loss of the solvent by volatil-ization. Each bottle is left in the oven for a different, and everincreasing, time period. The time period for the first bottle maybe as little as two hours, and that for the last bottle may be asmuch as one-hundred twenty hours or longer. After the 40Cexposure, the gr
22、anules are analyzed to determine the amount ofsolvent still retained. Successive time periods continue untilthe amount of solvent found in two or more successive samplesindicates more exposure time is not expected to cause signifi-cantly more loss of solvent.Analysis is by high pressure liquidchroma
23、tography (HPLC), gas chromatography (GC), or othermethods tested and proven to give accurate and reproducibleresults.5. Significance and Use5.1 This test method is designed specifically for emulsionsof pesticide emulsifiable concentrates.5.2 This test method provides information on theabsorption/ads
24、orption of solvents by simulated organic soil andinorganic soil impacted by pesticide EC emulsion applications.5.3 The amount of solvent lost by volatilization at 40C asdetermined by this method is an indirect measure of theatmospheric availability of the solvent to potentially react withnitrogen ox
25、ides to form tropospheric ozone, a major airpollutant.6. Apparatus6.1 Balance, sensitivity of 0.01 g.6.2 Roller System, two or more rollers with a drive bed,capable of rotating a glass bottle or jar, about 1 to 4 L in size,at 20 to 60 r/min.6.3 Glass bottle or jar, round, with screw-thread cap, for
26、usewith roller system. Typical size is 1 to 4 L.6.4 Oven, vented, mechanical convection, 40 6 2C, 2.0 ft3minimum inside capacity, 50 to 90 air exchanges per hour.6.5 125-mL laboratory media bottles, glass, round, outsidediameter about 55 mm, height about 123 mm, inside diameteropening about 30 mm, w
27、ith screw-thread caps. An example isWheaton brand, available from many laboratory supply com-panies.6.6 Apparatus required by the analytical test method.7. Reagents and Materials7.1 Corn cob granules, 20/40 Mesh7.2 Montmorillonite clay granules, LVM, 12/24 Mesh.7.3 Solvent to be tested.7.4 Emulsifyi
28、ng agent(s) suitable for emulsifying the sol-vent.7.5 Reagents and materials required by the analytical testmethod.8. Hazards8.1 Before testing, read the precautionary statements onproduct labels and the Material Safety Data Sheets (MSDS).Take proper precautions to prevent skin contact and inhalatio
29、nof fumes or dust. Take care to prevent contamination of thesurrounding area. Always wear the appropriate safety equip-ment and, where indicated, wear respiratory devices approvedby the National Institute of Occupational Safety and Health(NIOSH) for the product being tested.8.2 Store, handle, and di
30、spose of test materials with consid-eration for health and environmental safety, and in accordancewith federal, state, and local regulations.9. Sampling, Test Specimens, and Test Units9.1 The uniform mixing of the roller system procedureensures any size sample taken from the roller system jar is are
31、presentative sample. Do not use riffling to reduce a grosssample of the treated granules to a representative, suitable size.Significant volatilization of the solvent may occur duringriffling or any other time the granules are not in a sealedcontainer.10. Preparation of Apparatus10.1 For all apparatu
32、s, see the manufacturers instructionsfor proper operation and maintenance.11. Calibration and Standardization11.1 See the analytical test method to be used for determin-ing solvent content for information relative to calibration andadjustment of the apparatus necessary for the use of themethod.11.2
33、See the analytical test method for the standardizationand use of reference standards and blanks used in the method.E2686 09 (2015)212. Procedure12.1 Prepare an emulsifiable concentrate consisting only ofsolvent plus emulsifying agent(s). A typical formula is 90 to92 % solvent and 8 to 10 % emulsifyi
34、ng agent(s). Check theemulsion performance by adding 1 part concentrate to 14 partswater. Stir the mixture to form the emulsion. The emulsionshould form easily, remain free of separation for 15 min, andre-emulsify easily after sitting 24 h. If the concentrate does notmeet these performance limits, r
35、eformulate using a differentemulsifying agent(s). Keep the concentrate and the emulsion inclosed containers, regardless of the ambient temperature, toprevent loss of solvent by volatilization. Open the containersonly for the time needed to perform a necessary task.12.2 Analyze the concentrate for we
36、ight % solvent, usingthe same analytical method to be used for the treated granules.Repeat the analysis. The two analyses must not differ morethan 4 % from each other. Use the average to calculate themakeup of the emulsion to be used for treating the granules.12.3 Prepare one batch of emulsion treat
37、ed corn cob gran-ules and one batch of emulsion treated clay granules asdescribed below. These are the primary sampling units. Testunit samples are sub-units taken from these primary units.12.4 Keep all treated granules in closed containers, regard-less of the ambient temperature, to prevent loss of
38、 solvent byvolatilization. Open the containers only for the time needed toperform a necessary task.12.5 Typically, the desired weight % solvent in granules foranalysis by HPLC or GC is about 1% %. A suggested protocolfor the preparation of granules with 1 % solvent is as follows:Prepare a concentrat
39、e of 90 % solvent plus 10 % surfactant(s).Add 1.1 parts concentrate to 14 parts water. Add the resultingemulsion to 85 parts granules and mix to uniformity. Deter-mine the initial solvent content of the granules by extracting asample with a suitable analytical solvent followed by analysisof the extr
40、act. The weight of the sample, or test unit, for 40Cexposure and subsequent analysis is the weight determined tobe nominal for the analytical method.12.6 Begin preparation of the two batches of treated gran-ules by adding untreated granules to the glass bottle or jar to berotated on the roller syste
41、m. The granules should fill one-fourthto one-half the container for the best mixing by rotation tooccur.12.7 Add the emulsion to the granules in three equalincrements using enough total emulsion to give good distribu-tion of the liquid but not enough to wet the granules to the pointof significantly
42、changing their flow properties. Use a transferpipette to add the emulsion to the inside wall of the containerwhile the container is being tilted and rotated by hand.The goalis to spread the liquid in a thin film on the wall so that the liquiddoes not contact the granules in a concentrated area as wo
43、uldhappen by just pouring the liquid on the granules. Concentrat-ing the area where the liquid contacts the granules may causeclumps, which then require extra mixing care to re-fragment .12.8 Add the first emulsion increment, promptly cap thecontainer, and place it on the roller system at, typically
44、, 30 to50 r/min for a good cascading motion that gives good mixingof the granules inside. Rotate 10 min. Repeat the incrementadditions of emulsion and 10 min rotating two more times.12.9 Use an analytical method tested and proven to giveaccurate and reproducible results. HPLC and GC methods havebeen
45、 used successfully.12.10 Determine by trial and error the number of successivetime periods needed for tracking the loss of solvent from thegranules by volatilization at 40C to a plateau indicating furtherloss is not expected to be significant. A minimum of fivesuccessive time periods is needed to co
46、nclude the plateauoccurs; two of those periods must be 0 h and 72 h. Tracking iscompleted when the results from any two of three successivetime periods do not differ from each other by more than theaccuracy of the test method. See 15.2 for repeatability andreproducibility standard deviation and the
47、95 % repeatabilityand reproducibility limits on the difference between testresults.In the rare event it is concluded that a plateau for loss byvaporization will not be seen, the half-life for biodegradationof the solvent in soil can be used as a second tier end-point.Stop the testing after exposure
48、time at 40C equals 3 thebiodegradation half-life. The determination of soil biodegrada-tion half-life, itself, is beyond the scope of this test.12.11 A suggested sequence of successive time periods at40C for starting trial and error tests is: 0 h, 8 h, 24 h, 48 h, 72h, 96 h, and 120 h.12.12 A sugges
49、ted testing protocol is as follows: Preparethree sets of seven 125-mLmedia bottles containing the treatedgranules. Trial and error results may reduce or increase thenumber of samples actually needed.12.13 Weigh the empty bottle and cap to the nearest 0.01 g.Add a test unit (nominal weight) of granules to the bottle.Typically, the nominal weight of granules for HPLC analysis is5 g, and the nominal weight for GC analysis is 5 to 20 g. Usethe nominal weight specified by the analytical method for all40C exposures and solvent extractions.12.14 Weigh the bottle
