ASTM_D_4137_-_82_2012.pdf

Designation:D413782(Reapproved 2012)Standard Practice forPreserving Phytoplankton Samples1This standard is issued under the fixed designation D4137;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 practice describes the proper procedure for preserv-ing phytoplankton samples with either formaldehyde orLugols solution1.2 This standard does not purport to address all of thesafety problems,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.2.Referenced Document2.1 ASTM Standards:2D1193 Specification for Reagent Water3.Summary of Practice3.1 A phytoplankton sample collected with either a qualita-tive or quantitative sampler is preserved with either formalde-hyde solution or Lugols solution.4.Significance and Use4.1 Formaldehyde solution can be used as a permanentpreservative of algae.Lugols solution can be used to preservealgae for up to one year.Lugols is a more suitable preservativefor delicate algae such as naked flagellates.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type II of Specification D1193.5.3 Cupric Sulfate Solution(saturated)Dissolve 21 g ofCuSO4in 100 mL of water.5.4 Detergent Solution(20%)Dilute 20 mL of householdliquid detergent to 100 mL with water.5.5 Formaldehyde Solution,37 to 40%aqueous.5.6 Lugols SolutionDissolve 60 g of potassium iodideand 40 g of iodine crystals in 1000 mL of water.6.Procedure6.1 If the sample is to be examined within 2 to 3 h aftercollection,no special treatment is necessary.A phytoplanktonsample may be maintained for 24 h at 2 to 3C,but forextended storage,preservation is required.There are numerouspreservatives for phytoplankton of which formaldehyde solu-tion and Lugols solution are the most commonly used.6.2 To use formaldehyde solution,to each 1000 mL ofsample,add 30 mL of 37 to 40%aqueous formaldehydesolution(100%formalin),5 mL of 20%liquid detergentsolution,and 1 mL of saturated cupric sulfate solution.Thispreservative maintains cell coloration and is effective indefi-nitely.46.3 For delicate algal forms such as naked flagellates,Lugols solution is a more suitable preservative.Add 1 mLLugols solution to each 100 mL of sample and store in thedark.Lugols solution has been found to be effective for atleast 1 year.5It facilitates sedimentation of cells and maintainsfragile cell structures.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.24 on Water Microbiology.Current edition approved Sept.1,2012.Published November 2012.Originallyapproved in 1982.Last previous edition approved in 2004 as D4137 82(2004).DOI:10.1520/D4137-82R12.2For 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.3“Reagent Chemicals,American Chemical Society Specifications,”Am.Chemi-cal Soc.,Washington,DC.For suggestions on the testing of reagents not listed bytheAmerican Chemical Society,see“Reagent Chemicals and Standards,”by JosephRosin,D.Van Nostrand Co.,Inc.,New York,NY,and the“United StatesPharmacopeia.”4Greeson,P.E.,Ehlke,T.A.,Irwin,G.A.,Lium,B.W.,and Slack,K.V.,“Methods for Collection and Analysis of Aquatic Biological and MicrobiologicalSamples,”U.S.Geology Survey,Technology of Water-Resources Investigations,Book 5,Chapter A4,1977,332 pp.5Weber,C.I.,“The Preservation of Phytoplankton Grab Samples,”AmericanMicroscopical Society Transactions,Vol 87,pp.7081.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 ASTM 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 validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five ye