ASTM E1945-2002(2016) Standard Test Method for Percent Dispersibility《农药弥散率的标准试验方法》.pdf

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1、Designation: E1945 02 (Reapproved 2016)Standard Test Method forPercent Dispersibility1This standard is issued under the fixed designation E1945; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in

2、 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 is used to determine the percentdispersibility of dry pesticide formulations.1.2 The values stated in SI units are to be regard

3、ed 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 its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine

4、 the applica-bility of regulatory limitations prior to use. For specificprecautionary statements see Section 7.2. Referenced Documents2.1 ASTM Standards:2D1126 Test Method for Hardness in WaterD1193 Specification for Reagent Water3. Summary of Test Method3.1 A known amount of dry pesticide formulati

5、on is addedto a 250-mL mixing cylinder that has been filled to volumewith standard water. The mixing cylinder is then stoppered andinverted 30 times in 2 min. The mixing cylinder is allowed tostand for 1 min. After 1 min, the top 225 mL is drawn off andthe remaining suspension is dried. The residue

6、weight willdetermine percent dispersibility.4. Significance and Use4.1 This test method is designed specifically for dry formu-lations.4.2 This test method may not be applicable to all dryformulations such as those containing either liquid technicalsor ingredients that rise to the top upon separatio

7、n.4.3 This test method may not be applicable to those tech-nicals that decompose below the drying temperature.4.4 This test method should be run in duplicate.4.5 Products containing water soluble or volatile compo-nents may result in errors.5. Apparatus5.1 Balance, top loading, with an accuracy of 6

8、0.01 g orbetter.5.2 Gravity Oven.5.3 Weighing Dish, 150 mL capacity or greater.5.4 Vacuum Apparatus, see Fig. 1, equipped with a ventedstopper.5.5 Mixing Cylinder, stoppered, 250-mL, flat bottom.5.6 Timer, adjustable, with an accuracy of 61s.5.7 Weighing Dish, aluminum (57 18 mm) or petri dish orequ

9、ivalent.5.8 Filtering Flask, heavy wall, 500 mL.6. Reagents (Test Water)6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Ch

10、emical Societywhere such specifications are available.36.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean reagent water, Type IV, asdefined by Specification D1193.NOTE 1Type IV grade reagent water may be prepared by distillation,ion exchange, reverse osmosis

11、, electrodialysis, or a combination thereof.6.3 Synthetic Hard Water Stock, transfer 12.14 g of anhy-drous calcium chloride (CaCl2) and 5.55 g of magnesiumchloride hexahydrate (MgCl26H2O) to a 1000-mL volumetric1This test method is under the jurisdiction of ASTM Committee E35 onPesticides, Antimicro

12、bials, and Alternative Control Agents and is direct responsi-bility of Subcommittee E35.22 on Pesticide Formulations and Delivery SystemsCurrent edition approved Nov. 1, 2016. Published November 2016. Originallyapproved in 1998. Last previous edition approved in 2008 as E1945 02(2008).DOI: 10.1520/E

13、1945-02R16.2For 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 website.3Reagent Chemicals, American Chemical Society Spec

14、ifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Conve

15、ntion, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1flask. Dissolve the reagents with approximately 750 mL ofwater and equilibrate to 20C. Dilute the solution to 1000 mLtotal volume with water at 20C, stop

16、per the flask, and mix thesolution thoroughly. This mixture is equivalent to 13 680 ppmas calcium carbonate (CaCO3) and is based on a compositionalratio of 4:1 calcium carbonate to magnesium carbonate.6.3.1 Soft Water, equivalent to a total hardness of 34.2 ppmas calcium carbonate (CaCO3). Transfer

17、2.50 mL of synthetichard water stock by pipet to a 1000-mL volumetric flask anddilute to volume with water at 20C. Mix solution thoroughly.NOTE 2It is recommended that total hardness be checked in accor-dance with Test Method MT-73, CIPAC 1, EDTA titration.4An alternatemethod is provided in Test Met

18、hods D1126 where the value is representedas CaCO3. A value within 65 % of the nominal hardness value isacceptable.6.3.2 Hard Water, equivalent to a total hardness of 342 ppmas calcium carbonate (CaCO3). Transfer 25.0 mL of synthetichard water stock by buret to a 1000-mL volumetric flask anddilute to

19、 volume with water at 20C. Mix this solutionthoroughly (see Note 2).6.3.3 Extra-hard Water, equivalent to a total hardness of1000 ppm as calcium carbonate (CaCO3). Transfer 73.1 mL ofsynthetic hard water stock by buret to a 1000-mL volumetricflask and dilute to volume with water at 20C. Mix this sol

20、utionthoroughly (see Note 2).6.3.4 Other Test WatersOther synthetic waters can beprepared by using the following calculation:Desired Water Hardness13.6805 (1)milliliters of synthetichard water stock at 20Ctobediluted volumetrically to 1000 mLwith water at 20 C#.6.4 Other CarriersCarriers other than

21、water may be usedwhen appropriate.7. Safety Precautions7.1 Before testing, read the precautionary statements on theproduct label or the Material Safety Data Sheet (MSDS), orboth. Take proper precautions to prevent skin contact andinhalation of the fines or vapors, or both. Take care to preventcontam

22、ination of the surrounding area. Always wear theappropriate safety equipment and, where indicated, wear respi-ratory devices approved by the National Institute of Occupa-tional Safety and Health (NIOSH) for the product being tested.8. Procedure8.1 Each sample should be run in duplicate.8.1.1 Weigh a

23、 2.5-g sample into a weighing dish. Record thesample weight (W1) to an accuracy of 6 0.01 g.8.1.2 Fill a 250-mL mixing cylinder to volume with testwater and equilibrate to 20C 6 2C, (see Note 3).NOTE 3Other temperatures may be examined as defined by actualfield use applications.8.1.3 Transfer the sa

24、mple from 8.1.1 to the mixing cylinder.8.1.4 Stopper and invert the cylinder 30 times in twominutes.8.1.5 Let the mixing cylinders stand for 1 min.8.1.6 Remove 225 mL from the mixing cylinder using thevacuum apparatus in accordance with Section 5.4. Ensure thatthe tip of the suction tube remains sli

25、ghtly below the liquidsurface while removing the 225 mL. Take care not to disturbthe bottom 25-mL layer.8.1.7 Record the tare weight of the weighing dish to anaccuracy of 60.01 g.8.1.8 Gently swirl the remaining suspension to loosen thehard-packed material. Transfer quantitatively to the weighingdis

26、h. Rinse the cylinder with additional test water if necessary.8.1.9 Dry the weighing dish containing the residue from8.1.8 in a 50C gravity oven to a constant weight.8.1.10 Weigh the dish from 8.1.9 to an accuracy of 60.01 gand subtract the tare weight to determine the dried residueweight (W2).4“Phy

27、sico-Chemical Methods for Technical and Formulated Pesticides,” CIPACHandbook, Vvol F, compiled by W. Dorbat and A. Martin, Collaborative Interna-tional Pesticide Analytical Council Ltd., Great Britain, 1995.FIG. 1 Vacuum ApparatusE1945 02 (2016)29. Disposal of Sample9.1 After testing, store all mat

28、erials in a safe manner anddispose of used material in accordance with product labeldirections or MSDS, or both.10. Calculation10.1 Calculate % dispersibility of the WG as follows:% Dispersibility 51093W12 W2! 3100W1!(2)where:W1= sample weight and,W2= dried residue weight.11. Report11.1 Report perce

29、nt dispersibility, ambient temperature, andwater hardness.12. Precision and Bias12.1 RepeatabilityTwo results obtained by the same ana-lyst should be considered suspect if they differ by more than2.0 % absolute.12.2 ReproducibilityTwo results obtained by analysts indifferent laboratories should be c

30、onsidered suspect if theydiffer by more than 5.0 % absolute.12.3 BiasThis test method has no bias because the valueof dispersibility is defined only in terms of this test.13. Keywords13.1 dispersion; dry flowable (DF); dry flowable test meth-ods; percent dispersibility; water dispersible granules (W

31、G)(WDG); water dispersible granules test methods; wettablegranules test methodsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the vali

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35、opies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 02 (2016)3