1、SSPC-Guide 15 August 21, 20131SSPC: The Society for Protective CoatingsTechnology Guide 15Field Methods for Extraction and Analysisof Soluble Salts on Steel and Other Nonporous Substrates1. Scope1.1 This Guide describes the most commonly used field methods for the extraction and analysis of soluble
2、salts on steel and other nonporous substrates. Laboratory methods are only included for situations where more complete salt extrac-tions are desired through rigorous laboratory retrieval and analysis protocols. 2. Description and Use2.1 INTRODUCTION: Coatings applied on surfaces contaminated with so
3、luble salts exceeding a certain concentration exhibit diminished performance. Likewise, self-passivating metals (not intended for coating such as stain-less steel, aluminum and copper) can be compromised from elevated concentrations of residual soluble salts in corrosive environments. Soluble salt t
4、esting involves two basic steps: 1) extraction of salts from the surface into a solution and 2) the analysis of the solution. This Guide is intended to assist the user in selecting specific procedures for extracting and performing qualitative and/or quantitative soluble salts from steel and nonporou
5、s surfaces. It includes field methods for measuring total conductivity (fully automated or multi-step) and specific ions. It also offers guidance for destructive laboratory soluble salt extraction and testing. An overview of available field and laboratory techniques, methods of salt extraction and s
6、urface concentration calculations are provided in Tables 1 and 2 respectively. A discussion and sources on the efficiency of salt removal (also called extraction) from the metal surfaces of interest are provided in Appendix C. 2.1.1 Abbreviations:Cl-1chloride ioncm3cubic centimeterscm2square centime
7、tersFe+2ferrous ionS microSiemensS/cm microSiemens per centimetermg milligramml milliliterppm parts per millionNaCl sodium chlorideNO3-1nitrate ionSO4-2sulfate ion2.2 SALT EXTRACTION SOLUTIONSAll of the reagents used to extract salts from metal surfaces in this document fall into two categories: rea
8、gent water and proprietary aqueous solutions. They will be designated herein as reagent water or proprietary extraction solution.2.2.1 Reagent Water: Reagent water used for salt extrac-tion should have a maximum conductivity of 5 S/cm. Distilled water may be purchased at grocery stores but verificat
9、ion of the conductivity is recommended. Alternatively, a portable demineralizer may be used to make reagent water on site. Pour tap water into the plastic bottle, attach the demineralizer cartridge in the direction indicated, invert, and squeeze out the desired amount of water (for many of the tests
10、 described below, at least 25 ml will be required). The cartridge can be used until the blue color turns brown, as indicated on the side of the cartridge. Once this occurs, replace the cartridge. Each cartridge should deionize approximately 3000 ml of water.2.2.2 Proprietary Solutions: Proprietary e
11、xtraction solu-tions may be included with some commercial test kits. These solutions should only be used for the soluble salts described in the kit instructions. Proprietary solutions are not suitable for measuring conductivity of extracted solutions.3. Referenced StandardsThe standards listed below
12、 are updated on a periodic basis. The user of this guide should consult the most recent revision.3.1 SSPC STANDARDS AND JOINT STANDARDS:SP 5/NACE No. 1 White Metal Blast Cleaning3.2 ASTM INTERNATIONAL STANDARDS1ASTM D4327 Standard Test Method for Anions in Water by Chemically Suppressed Ion Chromato
13、graphyASTM D512 Standard Test Methods for Chloride Ion In Water1 ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. For referenced ASTM standards, visit the ASTM website, , or contact ASTM Customer Service at . For Annual Book of ASTM Standards volume information, refer to
14、the standards Document Summary page on the ASTM website.SSPC-Guide 15 August 21, 201323.2 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) STANDARDS:2ISO 8502 Preparation of steel substrates before application of paints and related products Tests for the assessment of surface cleanlinessPart 2 L
15、aboratory determination of chloride on cleaned surfaces (ISO 8502-2)Part 5 Measurement of chloride on steel 2 International Organization for Standardization (ISO), Case Postale 56, Geneva CH-1211, Switzerland. ISO standards may be obtained through the American National Standards Institute, 1819 L St
16、reet, NW, Suite 600, Washington, DC 20036 (www.ansi.org).surfaces prepared for paintingIon detection tube method (ISO 8502-5)Part 6 Extraction of soluble contaminants for analysisThe Bresle method (ISO 8502-6)Part 9 Field method for conductometric deter-mination of water-soluble salts (ISO 8502-9)Pa
17、rt 12 Field method for the titrimetric deter-mination of water-soluble ferrous ions (ISO 8502-12)TABLE 1OVERVIEW OF FIELD METHODS FOR RETRIEVAL AND ANALYSIS OF SOLUBLE SALTS FROM STEEL AND OTHER NONPOROUS SURFACESMethodology (see section number for more detail)Surface Sampling via Extraction Medium
18、(Applicable ISO Standard)Analysis of Extracted Sample Calculating Surface Concentrations of Ions (also refer to Appendix A or B)4. Field Methods Measuring Conductivity 4.1 Fully Automated Conductivity Measurement Techniques 4.1.1 Soluble Salt MeterEmploys Reagent Water for ExtractionManufacturer Cal
19、ibrationMagnetic Surface AttachmentIntegrated Conductivity Sensor Reported as conductivity S/cm mg/m2(ISO 8502-9)mg/m2as NaCl (IMO PSPC)4.1.2 Surface Salinity MeterEmploys Reagent Water for ExtractionManufacturer CalibrationMagnetic Surface AttachmentIntegrated Conductivity SensorReported as conduct
20、ivity S/cm mg/m2(ISO 8502-9)g/cm2as chlorides4.1.3 Continuous Flow Extraction Fiber StripEmploys Reagent Water for ExtractionManufacturer Calibration. User accuracy check provided.No-Residue Tape Surface AttachmentIntegrated Conductivity SensorReported as conductivity S/cm mg/m2(ISO 8502-9)g/cm2tota
21、l salts per ISO 8502-94.2 Multi Step Conductivity Measurement Techniques 4.2.1 Surface Swab or WashEmploys Reagent Water for Extraction (ISO 8502-2, Sections 5 and 6)Probe-Type Conductivity Meter Conductivity reported as S/cm (ISO 8502-9).4.2.2 Adhesively Bonded Latex Patch or CellEmploys Reagent Wa
22、ter for Extraction (ISO 8502-6)Probe-Type Conductivity Meter Conductivity reported as S/cm (ISO 8502-9).4.2.3 Saturated Special Filter Paper With Concentric Ring Conductivity Meter Employs Reagent Water for ExtractionConcentric Ring Conductivity MeterConductivity reported as g/cm2, mg/cm2, S/cm, ppm
23、, % salinity.SSPC-Guide 15 August 21, 20133TABLE 1OVERVIEW OF FIELD METHODS FOR RETRIEVAL AND ANALYSIS OF SOLUBLE SALTS FROM STEEL AND OTHER NONPOROUS SURFACESMethodology (see section number for more detail)Surface Sampling via Extraction Medium (Applicable ISO Standard)Analysis of Extracted Sample
24、Calculating Surface Concentrations of Ions (also refer to Appendix A or B)5. Field Methods Measuring Specific Ions5.1 Fully Automated Methods No automated or single-step specific-ion extraction/analyses are currently available.5.2 Multi-Step Ion-Specific Methods5.2.1 Chloride Ion Paper Strip Test of
25、 Swab/Wash or Latex Patch/Cell ExtractsEmploys Reagent Water for ExtractionSwab: ISO 8502-2, Sections 5 and 6) (Latex Patch/Cell: ISO 8502-6)Commercially Available Kit. Convert “QuanTab Units” to ppm per manufacture instructions. Convert solution concentration as ppm to surface concentration (g/cm2)
26、 per Appendix A.Calculation of surface Cl-1from swab as g/cm2(Cl-1 as ppm quantity of water used in ml) area sampled in cm25.2.2 Chloride Ion Detection Tube Test of Swab/Wash or Latex Patch/Cell ExtractsEmploys Reagent Water for ExtractionSwab: ISO 8502-2, Sections 5 and 6)(Latex Patch/Cell: ISO 850
27、2-6)Commercially Available Kit. Convert solution concentration as PPM to surface concentration (g/cm2) per Appendix A.Calculation of surface Cl-1from swab as g/cm2: (Cl-1as ppm quantity of water used in ml) area sampled in cm25.2.3 Ferrous Ion Paper Strip Test of Swab/Wash or Latex Patch/Cell Extrac
28、tsEmploys Reagent Water for Extraction(Swab: ISO 8502-2, Sections 5 and 6)(Latex Patch/Cell: ISO 8502-6)Commercially Available Kits. Ferrous solution concentration is measured visually. Color comparison to charts on ferrous ion strip bottle (units in ppm or (g/cm2). Convert solution concentration as
29、 ppm to surface concentration (g/cm2) per Appendix A. Fe+2from swab as g/cm2: (ppm ml of water) area sampled in cm25.2.4 Field Drop Titration for Chloride of Swab/Wash or Latex Patch/Cell ExtractsEmploys Reagent Water for Extraction(Swab: ISO 8502-2, Sections 5 and 6)(Latex Patch/Cell: ISO 8502-6)Co
30、mmercially Available Test Kit used to analyze aqueous extracted solutions. Chloride ion concentration is determined by “drop titration.” Cl-1concentration is calculated as follows:Convert number of drops to cause color change from surface area tested to determine concentration of chloride as g/cm25.
31、2.5 Latex Sleeve Methodology Proprietary Extraction Solution Single ion or multi-ion prepackaged commercial kits are available.-5.2.5.1 Sleeve Extract for Chloride OnlyProprietary Extraction Solution Chloride Ion Detection Tube. Units reported in ppm. Calculation of Surface Cl-1same as g/cm2(Cl-1as
32、ppm 10 ml Proprietary Extraction Solution with sleeve. Area sampled of 10 cm2yields 1:1 equivalence to g/cm2) (ISO 8502-5)SSPC-Guide 15 August 21, 201343.3 NACE INTERNATIONAL STANDARD3NACE SP0508-2010 Methods of Validating Equivalence to ISO 8502-9 on Measurement of the Levels of Soluble Salts4. Fie
33、ld Methods Measuring Total Soluble Salts by Conductivity4.1 Fully Automated Conductivity Measurement Tech-niques: Recent innovations in salinity testing devices have 3 NACE International, 1440 South Creek, Houston, TX 77084. NACE standards are available online at . resulted in direct, real-time auto
34、mated integrated systems that comply with ISO 8502-9. These devices are alternatives to patch cells and measure solution salinity from conductance. All of these devices attach to metal surfaces (magnetically or with non-residue tape). A fixed volume of pure extraction water is automatically dispense
35、d and agitated against the metal surface to remove (extract or retrieve) soluble salts and conductance measurements are taken in real-time. The devices process conductance data to generate surface concentration and store data and results internally. The commercially available devices are summarized
36、in Table 1, Sections 4.1.1 Soluble Salt Meter; 4.1.2 Surface Salinity Meter; and 4.1.3 Continuous Flow TABLE 1OVERVIEW OF FIELD METHODS FOR RETRIEVAL AND ANALYSIS OF SOLUBLE SALTS FROM STEEL AND OTHER NONPOROUS SURFACESMethodology (see section number for more detail)Surface Sampling via Extraction M
37、edium (Applicable ISO Standard)Analysis of Extracted Sample Calculating Surface Concentrations of Ions (also refer to Appendix A or B)5.2.5.2 Sleeve Extract for Ferrous IonProprietary Extraction Solution Ferrous Ion Test Strip immersed in sleeve solution to develop color. Color comparison to chart o
38、n ferrous test strip bottle. Units reported in ppm. Calculation of Surface Fe+2same as g/cm2(Fe+2as ppm; 10 ml proprietary extraction solution with sleeve. Area sampled of 10 cm2yields 1:1 equivalence to g/cm2)5.2.5.3 Sleeve Extract for Chloride, Nitrate, and Sulfate (CNS)Proprietary Extraction Solu
39、tion Nitrate Test Strip immersed in sleeve solution to develop color. color comparison to chart on nitrate test strip bottle.*Units reported in ppm.*See 5.2.5.1 for summary of analysis procedure for chloride and 5.2.5.4 for summary of analysis procedure for sulfate.Calculation of Surface NO3-1same a
40、s g/cm2(NO3-1as ppm; 10 ml proprietary extraction solution with sleeve. Area sampled of 10 cm2yields 1:1 equivalence to g/cm2)5.2.5.4 Sleeve Extract for SulfateProprietary Extraction Solution Sulfate Analysis by Colorimetric Methods. Concentration reported in ppm.Calculation of Surface SO4-2same as
41、g/cm2(SO4-2as ppm; 10 ml proprietary extraction solution with sleeve. Area sampled of 10 cm2yields 1:1 equivalence to g/cm2)5.2.6 Field Detection Sulfate IonEmploys Reagent Water for Extraction ( Swab: ISO 8502-2, Sections 5 and 6) (Latex Patch/Cell: ISO 8502-6)Sulfate Analysis by Optical Comparativ
42、e Method. Concentration reported in ppmCalculation of Surface SO4-2same as g/cm2SO4-2as ppm to surface concentration (g/cm2) per Appendix A or: ISO 8502-11, Sections 6 and 75.2.7 Qualitative Field Detection of Ferrous Ions-Blotting paper is treated with potassium ferricyanide solutions and wetted wi
43、th reagent water. On contact with ferrous ions, the paper shows blue spots.Not a quantitative technique.(ISO 8502-12)SSPC-Guide 15 August 21, 20135Extraction Fiber Strip. Additional product-specific information is available in each manufacturers website (refer to Appendix D).Note: As of May 2013, NA
44、VSEA Standard Item 009-32 FY 12 (Change 1)4requirement for solution conductivity for a Bresle Patch is V/A = 3 ml/1,250 mm2. If NAVSEA compli-ance is required, the reader must verify that the automated unit being employed calculates surface salt concentrations as specified by the version of NAVSEA S
45、tandard Item 009-32 invoked by the construction contract. 4.1.1 Soluble Salt Meter 4.1.1.1 Overview of the method: The soluble salt meter5is a hand-held device that is fully automated to perform both sample extraction and analysis. The device comes with a self-contained fluid dispenser that delivers
46、 accurate pre-measured volumes of reagent water for soluble salt measurements and post-measurement flushing. The device includes inter-changeable silicone-rubber lined magnetic heads of different curvatures, and provides on-screen instructions for use. The meter includes an interface for connection
47、to external periph-eral equipment. Soluble salt is measured as conductance (0-100 S/cm) or mg/m2. Additional specifications are available on manufacturers website.4.1.1.2 Extraction and Testing ProtocolStep 1. Attach the meter to test surface (if not magnetic, press unit against surface during testi
48、ng).Step 2. Inject reagent water into measurement chamber with one press of the dose bottle.Step 3. Meter automatically agitates solution.Step 4. Meter automatically takes readings (displays reading on LCD screen and stores values electronically).Step 5. Meter indicates completion of test cycle. Ste
49、p 6. Wipe remaining reagent water from surface after removing SSM and flush meter by turning over and injecting water from dose bottle. Unit is calibrated by the manufacturer. 4.1.1.3 Automatic Calculations reported as: conductivity S/cmmg/m2(ISO 8502-9)mg/m2as NaCl (IMO PSPC)6,74.1.2 Surface Salinity Meter 4.1.2.1 Overview of the method: The surface salinity meter8(SSM-21P), is another hand-held device that is fully 4 NAVSEA Standard Item 009-32, “Cleaning and Painting Requirements” is available as a .pdf from the National Surface
