1、Designation: D3352 08aD3352 15Standard Test Method forStrontium Ion in Brackish Water, Seawater, and Brines1This standard is issued under the fixed designation D3352; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This test method covers the determination of soluble strontium ion in brackish water, seawater, and brines by atomi
3、cabsorption spectrophotometry.1.2 Samples containing from 5 to 2100 mg/L of strontium may be analyzed by this test method.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this The valuesgiven in parentheses are mathematical conversions t
4、o inch-pound units that are provided for information only and are notconsidered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practice
5、s and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370
6、Practices for Sampling Water from Closed ConduitsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis3. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to Terminology D112
7、9.4. Summary of Test Method4.1 This test method is dependent on the fact that metallic elements, in the ground state, will absorb light of the same wavelengththey emit when excited. When radiation from a given excited element is passed through a flame containing ground state atoms ofthat element, th
8、e intensity of the transmitted radiation will decrease in proportion to the amount of the ground state element in theflame. A hollow cathode lamp whose cathode is made of the element to be determined provides the radiation. The metal atoms3to be measured are placed in the beam of radiation by aspira
9、ting the specimen into an oxidant-fuel flame.Amonochromator isolatesthe characteristic radiation from the hollow cathode lamp and a photosensitive device measures the attenuated transmittedradiation.4.2 Since the variable and sometimes high concentrations of matrix materials in the waters and brines
10、 affect absorptiondifferently, it is difficult to prepare standards sufficiently similar to the waters and brines. To overcome this difficulty, the method1 This test method is under the jurisdiction ofASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.05 on Inorganic Co
11、nstituents in Water.Current edition approved Nov. 15, 2008Feb. 1, 2015. Published November 2008April 2015. Originally approved in 1974. Last previous edition approved in 2008 asD3352 08.D3352 08a. DOI: 10.1520/D3352-08A.10.1520/D3352-15.2 For referencedASTM standards, visit theASTM website, www.astm
12、.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 For additional information on atomic absorption, see the following references: Angino, E. E., and Billings, G. K., Atomic
13、Absorption Spectrophotometry in Geology,Elsevier Publishing Co., New York, N.Y., 1967. Dean, J. A., and Rains, T. C., Editors, Flame Emission and Atomic Absorption Spectrometry Vol 1 Theory, Marcel Dekker,New York, NY, 1969.For additional information on atomic absorption, see the following reference
14、s: Angino, E. E., and Billings, G. K., Atomic Absorption Spectrophotometryin Geology, Elsevier Publishing Co., New York, N.Y., 1967; Dean, J. A., and Rains, T. C., Editors, Flame Emission and Atomic Absorption Spectrometry Vol 1 Theory,Marcel Dekker, New York, NY, 1969.This document is not an ASTM s
15、tandard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all c
16、ases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1of additions
17、is used in which three identical samples are prepared and varying amounts of a standard added to two of them. Thethree samples are then aspirated, the concentration readings recorded, and the original sample concentration calculated.5. Significance and Use5.1 This test method4 can be used to determi
18、ne strontium ions in brackish water, seawater, and brines.6. Interferences6.1 The chemical suppression caused by silicon, aluminum, and phosphate is controlled by adding lanthanum. The lanthanumalso controls ionization interference.7. Apparatus7.1 Atomic Absorption Spectrophotometer Spectrophotomete
19、rThe instrument shall consist of atomizer and burner, suitablepressure-regulating devices capable of maintaining constant oxidant and fuel pressure for the duration of the test, a hollow cathodelamp for each metal to be tested, an optical system capable of isolating the desired line of radiation, an
20、 adjustable slit, aphotomultiplier tube or other photosensitive device as a light measuring and amplifying device, and a read-out mechanism forindicating the amount of absorbed radiation.7.1.1 Multi-Element Hollow Cathode Lamps are available and have been found satisfactory.7.2 Pressure-Reducing Val
21、vesThe supplies of fuel and oxidant shall be maintained at pressures somewhat higher than thecontrolled operating pressure of the instrument by suitable valves.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intende
22、d that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society,5 wheresuch specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use withou
23、t lessening the accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean reagent water conforming toSpecification D1193, Type I. Other reagent water types may be used provided it is first ascertained that the water is of sufficiently
24、high purity to permit its use without adversely affecting the precision and bias of the test method. Type III water was specified atthe time of round robin testing of this test method.8.3 Filter PaperPurchase suitable filter paper.Typically the filter papers have a pore size of 0.45-m membrane. Mate
25、rial suchas fine-textured, acid-washed, ashless paper, or glass fiber paper are acceptable. The user must first ascertain that the filter paperis of sufficient purity to use without adversely affecting the bias and precision of the test method.8.4 Lanthanum Solution (5 % La)Wet 58.65 g of lanthanum
26、oxide (La2O3) with water. Add 250 mL of concentratedhydrochloric acid (sp gr 1.19) very slowly until the material is dissolved. Dilute solution to 1 litre with water.4 Additional information is contained in the following references: Fletcher, G. F., and Collins,A. G., “AtomicAbsorption Methods ofAna
27、lysis of Oilfield Brines: Barium,Calcium, Copper, Iron, Lead, Lithium, Magnesium, Manganese, Potassium, Sodium, Strontium, and Zinc,” U.S. Bureau of Mines, Report of Investigations 7861, 1974, 14pp. Collins, A. G., Geochemistry of Oilfield Waters, Elsevier Publishing Co., Amsterdam. The Netherlands,
28、 1975.Additional information is contained in the followingreferences: Fletcher, G. F., and Collins, A. G., “Atomic Absorption Methods of Analysis of Oilfield Brines: Barium, Calcium, Copper, Iron, Lead, Lithium, Magnesium,Manganese, Potassium, Sodium, Strontium, and Zinc,” U.S. Bureau of Mines, Repo
29、rt of Investigations 7861, 1974, 14 pp.; Collins, A. G., Geochemistry of Oilfield Waters,Elsevier Publishing Co., Amsterdam, Netherlands, 1975.5 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not list
30、ed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.TABLE 1 Compositions of Artificial Brine SamplesSample No. g/L1 2 3 4S
31、r 0.060 0.100 1.600 2.100NaCl 24.0 170.0 80.0 200.0KCl 0.5 2.0 1.5 3.0KBr 1.0 2.0 2.0 2.0KI 0.1 0.5 0.5 1.0CaCl2 1.5 3.0 2.0 5.0MgCl2 4.5 5.0 2.0 1.0BaCl2 0.05 1.0 0.5 0.5D3352 1528.5 Strontium Solution, Standard (1 mL = 1 mg Sr)Dissolve 2.415 g of strontium nitrate Sr(NO3)2 in 10 mL of concentrated
32、hydrochloric acid (sp gr 1.19) and about 700 mL of water. Dilute solution to 1 L with water. One millilitre of this solution contains1 mg of strontium. Alternatively, certified strontium stock solutions are commercially available through chemical supply vendorsand may be used.A purchased strontium s
33、tock solution of appropriate known purity is also acceptable.8.6 Oxidant, for Atomic Absorption Spectrophotometer:8.6.1 Air, which has been cleaned and dried through a suitable filter to remove oil, water, and other foreign substances, is theusual oxidant.8.6.2 Nitrous Oxide may be required as an ox
34、idant for refractory-type metals.8.7 Fuel, for Atomic Absorption Spectrophotometer:8.7.1 AcetyleneStandard, commercially available acetylene is the usual fuel. Acetone, always present in acetylene cylinders,can be prevented from entering and damaging the burner head by replacing a cylinder which onl
35、y has 100 psig 689 kPa (100 psi)of acetylene remaining.9. Sampling9.1 Collect the sample in accordance with Practices D3370.10. Procedure10.1 Strontium is determined at the 460.7-nm wavelength with an air-acetylene flame.10.2 Preliminary CalibrationUsing micropipets prepare standard strontium soluti
36、ons containing 1 to 10 mg/L of strontiumusing the standard strontium solution (8.5) and 50-mL volumetric flasks. Before making up to volume, add to each of these andto a blank, 5 mL of the lanthanum solution. solution (8.4). Analyze at least three working standards containing concentrations ofstront
37、ium that bracket the expected sample concentration, prior to analysis of samples, to calibrate the instrument. Aspirate thesestandards and the blank (for background setting) and adjust the curvature controls, if necessary, to obtain a linear relationshipbetween absorbance and the actual concentratio
38、n of the standards.10.3 Transfer an aliquot of water or brine (previously filtered (8.3) through a 0.45-m filter) to a 50-mL volumetric flask. Thespecific gravity of the water or brine can be used to estimate the strontium content of the sample and, thereby, serve as a basis forselecting the aliquot
39、 size that will contain about 0.1 mg of strontium. Fig. 1 shows the relationship between strontium concentrationand specific gravity for some oilfield brines from the Smackover formation. The concentrations of strontium in the Smackoverbrines will not necessarily correlate with the concentrations fo
40、und in other formations. Therefore, the user of this test method mayfind it necessary to draw a similar curve for brine samples taken from other formations.Add 5 mLof the lanthanum stock solution,solution (8.4), dilute to volume, and aspirate. Calculate the approximate sample concentration from the
41、preliminary calibrationreadings, and determine the aliquot size that will contain about 0.1 mg of strontium.10.4 Transfer equal aliquots containing about 0.1 mg of strontium to three 50-mL volumetric flasks.Add no strontium standardto the first flask. With a micropipet add 0.1 mg to the second and 0
42、.2 mg to the third.10.5 Add 5 mL of the lanthanum solution (8.4) to each of the three flasks and dilute to volume. Aspirate and record the directconcentration of the sample, if this capability is provided with the instrument or record the absorbance readings for each sample.11. Calculation11.1 Calcu
43、late the concentration of strontium ion in the original sample in milligrams per litre as follows:Strontium concentration,mg/L5 V1As3Cstd!V2A std2As!where:V1 = volume of the diluted samples, mL,V2 = volume of the original sample, mL,As = absorbance of dilute sample,TABLE 2 Determination of Precision
44、 and Bias of Strontium IonAmountAdded,mg/LAmountFound,mg/LSO ST BiasStatisticallySignificant(95 %ConfidenceLevel)60 63.48 2.96 8.49 + 5.8 yes100 99.5 4.12 11.84 0.5 no1600 1665.6 54.87 157.3 + 4.1 no2100 2167.2 71.12 203.9 + 3.2 noD3352 153Astd = absorbance of one of the standard additions, andCstd
45、= concentration of the same standard addition as Astd, mg/L.Since there are two standard additions, calculate for each and average the two results.12. Precision and Bias612.1 The precision of the test method within its designated range may be expressed as follows:S t 50.0929X12.596So 50.0324X10.901w
46、herewhere:St = overall precision,So = single-operator precision, and6 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D19-1022. Contact ASTM CustomerService at serviceastm.org.FIG. 1 Relationship of the Concentration of Strontiu
47、m in Some Oilfield (Smackover) Brines to Specific GravityD3352 154X = concentration of strontium determined, mg/L.12.2 The bias of the test method determined from recoveries of known amounts of strontium in a series of prepared standardsare given in Table 2.NOTE 1The above precision and bias estimat
48、es are based on an interlaboratory study on four artificial brine samples containing various amounts ofstrontium and interfering ions as shown in Table 1. One analyst in each of three laboratories and two analysts in each of six laboratories performedduplicate determinations on each of two days. Pra
49、ctice D2777 was used in developing these precision and bias estimates.12.3 Precision and bias for this test method conforms to Practice D2777 77, which was in place at the time of collaborativetesting. Under the allowances made in 1.4 of D2777 06, 13, these precision and bias data do meet existing requirements forinterlaboratory studies of Committee D19 test methods.13. Quality Control (QC)13.1 In order to be certain that analytical values obtained using these test methods are valid and accurate within the confidencelimits of the test, the foll
