1、Designation: D6363 98 (Reapproved 2013)Standard Test Method forDetermination of Hydrogen Peroxide and Combined OrganicPeroxides in Atmospheric Water Samples by PeroxidaseEnzyme Fluorescence Method1This standard is issued under the fixed designation D6363; the number immediately following the designa
2、tion 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 covers the deter
3、mination ofhydroperoxides, which include hydrogen peroxide (H2O2) andcombined organic peroxides, in samples of atmospheric waterby the method of horseradish peroxidase derivatization andfluorescence analysis of the derived dimer.2,31.2 The range of applicable hydrogen peroxide concentra-tions was de
4、termined to be 0.6 - 176.0 106M fromindependent laboratory tests of the test method.1.3 The primary use of the test method is for hydrogenperoxide, but it may also be used to quantitate organichydroperoxides. Determinations of organic hydroperoxide con-centration levels up to 30 106M may be adequate
5、lyobtained by calibration with hydrogen peroxide.2,3Whileorganic hydroperoxides have not been detected at significantconcentration levels in rain or cloud water, their presence maybe tested by operation of the test method with the addition ofcatalase for destruction of H2O23.1.4 Because of the insta
6、bility of hydroperoxides in atmo-spheric water samples, proper sample collection, at-collectionderivatization, and stringent quality control are essential as-pects of the analytical process.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It i
7、s 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 ASTM Standards:4D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD1356 Term
8、inology Relating to Sampling and Analysis ofAtmospheresD5012 Guide for Preparation of Materials Used for theCollection and Preservation of Atmospheric Wet Deposi-tionD5111 Guide for Choosing Locations and Sampling Meth-ods to Monitor Atmospheric Deposition at Non-UrbanLocationsE200 Practice for Prep
9、aration, Standardization, and Storageof Standard and Reagent Solutions for Chemical Analysis3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminologies D1129 and D1356 and GuideD5111.3.2 Definitions of Terms Specific to This Standard:3.2.1 atmospheric water,
10、 nliquid or solid water suspendedin the atmosphere or deposited from the atmosphere. Forms ofatmospheric water include rain, snow, fog, cloud water, dew,and frost.3.2.2 derivatization, nformation of thep-hydroxyphenylacetic acidic dimer by combination ofp-hydroxyphenylacetic acid, horseradish peroxi
11、dase reagent,and hydroperoxide(s). Also the procedure of addition of thederivatizing reagent to samples.3.2.3 hydroperoxides, nhydrogen peroxide and organicperoxides dissolved in water.3.2.4 intrinsic hydroperoxides, nhydroperoxides con-tained in reagent water used for the method.3.2.5 post-derivati
12、zation, naddition of the derivatizingreagent to the sample after collection.1This guide is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Oct. 1, 2013. Published Oc
13、tober 2013. Originallyapproved in 1998. Last previous edition approved in 2003 as D6363 - 98(09)1.DOI: 10.1520/D6363-98R13.2Lazrus, A. L., Kok, G. L., Gitlin, S. N., and Lind, J. A., “AutomatedFluorometric Method for Hydrogen Peroxide in Atmospheric Precipitation,” Anal.Chem., 57, 1985, pp. 917922.3
14、Kok, G. L., Thompson, K., and Lazrus,A. L., “Derivatization Technique for theDetermination of Peroxides in Precipitation,” Anal. Chem., 58, 1986, pp.11921194.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
15、STMStandards 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 States13.2.6 pre-derivatization, naddition of the derivatizing re-agent to the sample collection
16、 container prior to samplecollection.3.2.7 systems blank, na field blank of reagent water that issubjected to a similar or identical environment and derivatiza-tion time as a collected atmospheric water sample.3.2.8 systems standard, naH2O2calibration standardsolution subjected to a similar or ident
17、ical environment andderivatization time as a collected atmospheric water sample.4. Summary of Test Method4.1 The peroxidase enzyme fluorescence method is based onthe reaction of hydroperoxides, horseradish peroxidase, andp-hydroxyphenylacetic (PHOPAA) acid, forming a fluorescentdimer of the latter.
18、This dimer is detected using a fluorometrictechnique, and the hydroperoxides are quantified by calibrationwith hydrogen peroxide. The formation of the dimer (deriva-tization) shall be accomplished soon after sample collection tominimize H2O2decay. In addition, strict quality assurancepractices are p
19、art of the method, including use of systemsstandards and systems blanks to estimate hydroperoxide lossand to assess derivatizing solution effectiveness.5. Significance and Use5.1 Hydrogen peroxide (formed photochemically in theatmosphere) is a primary oxidizer of dissolved sulfur dioxide inatmospher
20、ic water. Detection of H2O2in atmospheric water isuseful for inferring gas-phase H2O2concentrations and forassessing the relative importance of various acidifying mecha-nisms under specific atmospheric conditions.5.2 Hydroperoxides in samples to be analyzed are unstablein water and can decay rapidly
21、 due to bacterial action orchemical reaction with other constituents. The test methodincludes procedures for sample derivatization and methods forestimating and correcting for hydroperoxide decay.6. Interferences6.1 The derivatizing reagent is formulated to counteract theeffects of the following pot
22、entially interfering species.6.2 Hydroxymethane Sulfonate (HMSA)The addition offormaldehyde (HCHO) to the derivatizing reagent will sup-press the negative interference of HMSA. In the absence ofadded HCHO, the PHOPAA dimer in a derivatized simulatedrain sample, containing 1.2 105MH2O2and 1.0 104MHMS
23、A, displayed a fluorescence signal 5 % lower than thatobserved when HCHO was added to the derivatizing reagent.36.3 Trace Transition Metals and Common Ionic Compo-nents of Atmospheric Water (Sodium, Ammonium, Hydrogen,Sulfate, Nitrate, Chloride, Formate)Potential interference bytransition metals is
24、overcome by the formation of ethylenedi-aminetetraacetic acid (EDTA) complexes. Tests of simulatedrain samples containing transition metals and common ioniccomponents of precipitation have demonstrated both the gen-eral applicability of this test method to samples containingcommon contaminants and t
25、he stability of derivatized solutionsstored at 4C for more than five days.37. Apparatus7.1 Flow System, consisting of the following:7.1.1 Automatic sampler or injection valve.7.1.2 Automated wet chemistry (peristaltic) pump.7.1.3 Reagent manifold.7.1.4 Mixing coil; 5-turn, 2-mm inner diameter.7.1.5
26、Fluorometer; excitation at 320 nm and measurementof the fluorescence signal at 400 nm; flow-through fluorescencecell.7.1.6 Recorder.7.2 Sample and Standards ContainersAll containers usedfor sample collection and sample transport, for storage andanalysis of samples and standards, and for reagents sho
27、uld behigh density polyethylene, TFE-fluorocarbon, or borosilicateglass, cleaned in accordance with procedures established foranalyses of common inorganic ions (see Guide D5012).7.3 Pipettes with Disposable TipsSolution preparation andsample fixing operations are generally conducted using auto-matic
28、 pipettes. Solution volumes delivered by these devicesshould be verified to confirm consistent and accurate perfor-mance.57.4 Reagent BottlesAll containers used for the preparationand storage of derivatizing and other reagent solutions shall bededicated for hydroperoxides. Containers for solutions o
29、fcatalase shall not be used for non-catalase solutions.8. Reagents and Materials8.1 Purity of ReagentsUnless otherwise noted, reagentgrade chemicals shall be used.68.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type I of Speci
30、fication D1193, with the added stipulationthat the total organic carbon content be less than 20 g/L. AType I water system equipped with an organic extractioncartridge and a 0.2 m filter is an acceptable water source.Water to be used for reagents, standard solutions, and analyti-cal rinsing should be
31、 stored in borosilicate glass.8.3 Catalase Enzyme (1.7 106units/mL)7The enzymecatalase may be used for the destruction of H2O2in atmo-spheric water samples. Its addition to the sample beforeaddition of the derivatizing reagent removes H2O2, but organichydroperoxides are preserved. Subsequent additio
32、n of thederivatizing reagent results in dimer formation by way ofreaction with peroxides other than H2O2. Results of analyses ofcatalase-treated samples may be compared with the measure-ment of peroxides in samples without catalase to determineH2O2by difference.5Schwartz, L.M., “Calibration of Pipet
33、s: A Statistical View,” AnalyticalChemistry, Vol. 61, 1989, pp. 10801083.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryC
34、hemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.7Catalase enzyme, 1.7 106units/mL, has been found satisfactory for thispurpose. Available through Sigma Chemical Co., P.O. Box 14508, St. Louis,
35、 MO63178.D6363 98 (2013)28.3.1 Catalase, 1+49Dilute 1 mL of catalase enzyme toa final volume of 50 mL with water. Before pipetting theconcentrated solution, ensure that all the solid material iscompletely suspended by shaking or stirring the bottle ofconcentrate. Allow the dilute solution to stand a
36、t least 4 hbefore use. The solution can be stored for up to 48 h at 4C.8.4 Derivatizing Reagent, ConcentratedDissolve 12.11 gof Tris(hydroxymethyl)aminomethane, 0.38 g of EDTA, tetra-sodium salt, 4.57 g of PHOPAA, 300 units of horseradishperoxidase, and 1 mL concentrated hydrochloric acid in water,a
37、nd dilute to 200 mL in a volumetric flask. The final pH of thissolution should be 9.0. If greater than 9.5 or less than 8.5,remake. Prepare every four days and store at 4C. Measure-ment of peroxides in aqueous atmospheric samples is based onthe fluorescence of the PHOPAA dimer produced by reactionof
38、 hydroperoxides with PHOPAA. The fluorescence of samplesderivatized at the time of collection provides a measure of totalhydroperoxide (organic and H2O2) content of the sample.8.4.1 Derivatizing Reagent, 4 + 96Dilute 4.0 mL of theconcentrated derivatizing reagent to 100 mL with water.Prepare daily a
39、s needed, and keep tightly sealed at 4C.NOTE 1The dilute derivatizing reagent is normally added to samplesto be analyzed in the reagent:sample ratio of 1:1. Other concentrations ofdilute derivatizing reagent may be used as long as the final ratio enteringthe analytical system is 1:1. Under special c
40、ircumstances, other ratios maybe dictated by sampling conditions (see 10.6 and 10.7).8.5 Hydrochloric Acid (HCl), (1 M)Add 8.3 mL concen-trated HCl to water in a volumetric flask and dilute to 100 mL.8.6 Peroxide Solution, Standard Stock (1 %)Dilute com-mercially available (pharmaceutical grade is a
41、cceptable) H2O2solution (30 %) approximately1+29with water in a volu-metric flask. Add sodium stannate (Na2SnO3) to a concentra-tion of 10.65 mg/L and store at 4C, and store in a borosilicateglass bottle. Determine the peroxide concentration by titrationwith standard permanganate solution (see 11.2)
42、 approximately24 h after preparation. Update the concentration determinationby titration at one month intervals.8.6.1 Peroxide Solution, 1 + 199Dilute 500 L of thestandard stock (1 %) solution to 100 mL with water in avolumetric flask. The approximate H2O2concentration of theresulting solution is 15
43、00 M (50 mg/L). Calibration standardsare prepared immediately before sample analysis by dilutingaliquots of this solution (see 11.3).8.6.2 Peroxide Solution, Systems BlankWater combinedwith dilute derivatizing reagent to the ratio 1:1. Prepare inperoxide calibration standard vials or in sample colle
44、ctioncontainers, depending on the derivatization method (see Sec-tion 10).8.6.3 Peroxide Solution, Systems StandardSee 11.3. Pre-pare in vials used for peroxide calibration standards or insample collection containers, depending on the derivatizationmethod (see Section 10).8.7 Potassium Permanganate
45、(KMnO4)Solution, Standard(0.01 M)Dissolve 1.58 g KMnO4in 100 mLwater, and dilutethe solution with water to 1 L. Seal tightly, and store in anamber borosilicate glass bottle in the dark. Standardize follow-ing the procedure in Practice E200, Sections 6468; adjustchemical proportions according to 9.1
46、of that Practice.8.8 Sodium Hydroxide (NaOH) (0.1 M)Dissolve 4.0 g ofsodium hydroxide in water and dilute to 1 L. Prepare weekly.8.9 Sulfuric Acid (H2SO4), 5 % (3.6 M)Add 5 mL con-centrated H2SO4to water in a volumetric flask, and dilute to100 mL.9. Sample Collection9.1 Select sampling locations and
47、 sampling methods inaccordance with Guide D5111. Additional considerations spe-cific to sampling for aqueous-phase hydrogen peroxide areprovided in 9.3 and 9.4.9.2 Methods of preparation of sample containers forcollection, transport, and storage shall be those detailed inGuide D5012 under inorganic
48、ionic species (see 8.1 and 8.2 ofGuide D5012).9.3 Control procedures designed to ensure sample integrityin the field (see Section 10) are difficult to perform adequatelyif buckets or other high atmospheric-exposure collectors areused. Therefore, sampling for rain should be conducted usingfunnel-and-
49、bottle type, or narrow-necked, collectors.9.4 The requirements for controlled derivatization of hy-droperoxides and timely analysis (see Section 10) dictate thatsampling for wet deposition be conducted on a daily or morefrequent basis.10. Derivatization10.1 The following procedures shall be in addition to thosespecified for preservation of inorganic anions and cations inGuide D5012 (see Table 1 of Guide D5012).10.2 Hydroperoxides dissolved in atmospheric water solu-tions are subject to decay at rates that are not predictable.T
