ASTM_E_1673_-_96_2012.pdf

Designation:E167396(Reapproved 2012)Standard Test Method forPercent Suspensibility1This standard is issued under the fixed designation E1673;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 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 percentsuspensibility of dry pesticide formulations.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 its 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.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 Aknown quantity of dry pesticide is slurried into 50 mLof test water in a 100-mL beaker.The slurry is quantitativelytransferred to a 250-mL mixing cylinder using additional testwater to rinse the beaker.The 250-mL mixing cylinder is thenfilled to volume with test water.The mixing cylinder isstoppered and inverted 15 complete cycles.The mixing cylin-der is allowed to stand for 30 min.After 30 min the top 225 mLis drawn off and the remaining suspension is dried.The residueweight will determine the percent suspensibility.4.Significance and Use4.1 This test method is designed specifically for dryformulations,but need not be restricted to these materials.4.2 Either option of this test method(see Section 8)may beused to determine the percent suspensibility.4.3 This test method may not be applicable to all dryformulations such as those containing either liquids or ingre-dients that rise to the top upon separation.4.4 This test method may not be applicable to formulationscontaining ingredients that decompose under the test condi-tions.4.5 This test method may not give reproducible results ifflocculation occurs.4.6 This test method should be run in duplicate.4.7 Products containing water soluble or volatile compo-nents may result in errors.5.Apparatus5.1 Balance,top loading,with an accuracy of 60.01 g orbetter.5.2 Beaker,100 mL.5.3 Mixing Cylinder,stoppered,250 mL,flat bottom,KI-MAX series 20039 or equivalent.5.4 Timer,adjustable,with an accuracy of 6 min.5.5 Magnetic Stirrer,120 to 1200 rpm,or equivalent.5.6 Stir Bar,magnetic 1 in.in length and38in.in diameter(2.5 cm 1 cm).5.7 Weighing Dish,aluminum(57 18 mm)or petri dish,orequivalent.5.8 Vacuum Apparatus,see Fig.1,equipped with a ventedstopper to prevent the formation of a vacuum.5.9 Filtering Flask,heavy wall,500 mL,KIMAX Series27060 or equivalent.5.10 Gravity Oven.5.11 Centrifuge,any centrifuge capable of holding a 50 mLor larger tube and maintaining a minimum speed of 1500 rpm.5.12 Centrifuge Tube,plastic or glass,50 mL or larger.6.Reagents(Test Water)6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended that1This 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 Oct.1,2012.Published October 2012.Originallyapproved in 1995.Last previous edition approved in 2006 as E1673 96(2006).DOI:10.1520/E1673-96R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 all reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical 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.NOTE1Type IV grade reagent water may be prepared by distillation,ion exchange,reverse osmosis,electrodialysis,or a combination thereof.6.3 Synthetic Hard Water StockTransfer 12.14 g of anhy-drous calcium chloride(CaCl2)and 5.55 g of magnesiumchloride hexahydrate(MgCl26H2O)to a 1000-mL volumetricflask.Dissolve the reagents with approximately 750 mL ofwater and equilibrate to 20C.Dilute the solution to 1000 mLtotal volume with water at 20C,stopper 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 WaterEq