UOP 714-2007 METALS IN MISCELLANEOUS SAMPLES BY ICP-OES.pdf

1、 IT IS THE USERS RESPONSIBILITY TO ESTABLISH APPROPRIATE PRECAUTIONARY PRACTICES AND TO DETERMINE THE APPLICABILITY OF REGULATORY LIMITATIONS PRIOR TO USE. EFFECTIVE HEALTH AND SAFETY PRACTICES ARE TO BE FOLLOWED WHEN UTILIZING THIS PROCEDURE. FAILURE TO UTILIZE THIS PROCEDURE IN THE MANNER PRESCRIB

2、ED HEREIN CAN BE HAZARDOUS. MATERIAL SAFETY DATA SHEETS (MSDS) OR EXPERIMENTAL MATERIAL SAFETY DATA SHEETS (EMSDS) FOR ALL OF THE MATERIALS USED IN THIS PROCEDURE SHOULD BE REVIEWED FOR SELECTION OF THE APPROPRIATE PERSONAL PROTECTION EQUIPMENT (PPE). COPYRIGHT 1971, 1987, 2007 UOP LLC. All rights r

3、eserved. Nonconfidential UOP Methods are available from ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. The UOP Methods may be obtained through the ASTM website, www.astm.org, or by contacting Customer Service at serviceastm.org, 610.832.9555

4、FAX, or 610.832.9585 PHONE. Metals in Miscellaneous Samples by ICP-OES UOP Method 714-07 Scope This method is for determining metals in samples of unknown composition such as residues and deposits. Aluminum (Al), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (P

5、b), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), sodium (Na), strontium (Sr), tin (Sn), titanium (Ti), vanadium (V), zinc (Zn), and zirconium (Zr) are quantitatively determined by Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). Concentrations det

6、ermined generally cover the range of 0.02 to several mass-%, see Table 1. Sample dilution extends the working range for major (matrix) components. If requested, additional elements can be determined, if the sample preparation method is appropriate for the additional elements. Table 1 Applicable Conc

7、entration Ranges, Mass-% Element Range Element Range Aluminum 0.02 - 2.5 Manganese 0.01 - 2.5 Cadmium 0.02 - 1.25 Molybdenum 0.03 - 2.5 Calcium 0.01 - 10 Nickel 0.03 - 2.5 Chromium 0.03 - 2.5 Potassium 0.10 - 2.5 Cobalt 0.02 - 2.5 Sodium 0.01 - 10 Copper 0.01 - 1.25 Tin 0.05 - 2.5 Iron 0.02 - 50 Tit

8、anium 0.01 - 1.25 Lead 0.05 - 2.5 Vanadium 0.01 - 5 Magnesium 0.01 - 10 Zinc 0.02 - 2.5 Barium (Ba) and silicon (Si) cannot be determined by this method due to the acid treatment of samples. Alpha-alumina will not dissolve in the acid media used in this method. An alternative microwave-based dissolu

9、tion technique is described in the Appendix. Silicon can be determined using the microwave-based dissolution technique; and instructions for the analysis of silicon are included. 2 of 11 714-07 References ASTM Method D 1193, “Specification for Reagent Water,” www.astm.org UOP Method 954, “Loss on Ig

10、nition for Fresh, Regenerated, Used, and Spent Catalysts, Catalyst Supports, and Adsorbents,” www.astm.org UOP Method 999, “Precision Statements in UOP Methods,” www.astm.org Outline of Method The samples are decomposed by digestion with sulfuric and hydrofluoric acids. The addition of hydrofluoric

11、acid and heating the digest volatilizes silica. Additional acid treatments may be necessary, depending upon the sample matrix. Scandium is added to the solution as the internal standard and the sample solutions are analyzed by ICPOES calibrated with appropriate, matrix(acid)-matched standards. Appar

12、atus References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Balance, readability 0.1-mg Beaker, Teflon, PTFE, 250-mL, Fisher Scientific, Cat. No. 02-593-5B Bottle, wash, polyethylene, 500-mL, VWR, Cat. No. 16651-187 Sample grinding

13、equipment Balls, grinding, 11.1-mm (7/16-inch), tungsten carbide, SPEX Industries, Inc., Cat. No. 8004A, or equivalent Container, grinding, 57 x 64 mm (2-1/4 x 2-1/2 inches), tungsten carbide, SPEX Industries, Inc., Cat. No. 8004, or equivalent Mixing mill, shaker type, SPEX Industries, Inc., Cat. N

14、o. 8000 Mortar and pestle, Agate, VWR, Cat. No. 50410-060 Cylinders, graduated, polypropylene, Class B, 10- and 100-mL, Fisher Scientific, Cat. Nos. 08-572A and -572D, respectively Flasks, volumetric, Class B, Nalgene polypropylene, 100, 200, and 500-mL capacity, Fisher Scientific, Cat. Nos. 10-198-

15、50B, -50C, and -50E respectively, several of each required Hot plate, stirring, variable heat to at least 400 C Pipet, microliter, 2500-L capacity, Rainin Instrument Co., Cat. No. EP-2500 Pipet, 10-mL capacity, Rainin Instrument Co., Cat. No. EP-10ML Pipets, volumetric, transfer, Class A, 1-, 2-, 5-

16、, 10-, 20-, 25-, 40-, and 50-mL, Fisher Scientific, Cat. Nos.13-650-2B, -2C, -2F, -2L, -2N, -2P, -2R, and -2S, respectively Regulator, argon, two-stage, high-purity, delivery pressure range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-580 Regulator, nitrogen, two-stage, high-purity, delivery

17、 pressure range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-580 3 of 11 714-07 Spectrometer, Inductively Coupled Plasma-Optical Emission Spectrometer, computer controlled, having sufficient resolving power and dispersion to separate the analytical lines in the 160-800 nm region. The compute

18、r must be capable of performing background corrections, blank corrections, and weight/volume and dilution corrections. A commercial grating spectrometer with a band pass of 0.018 nm or less in the first order is satisfactory. PerkinElmer Optima 5300 V Watch glass, Teflon, PTFE, 75-mm diameter, Fishe

19、r Scientific, Cat. No. 02-610-5C Weighing scoop, Fisher Scientific, Cat. No., 01-914-36 Reagents and Materials References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. References to water mean ASTM D 1193 Type I reagent grade water. A

20、rgon, 99.995% minimum purity, ICP feed gas Hydrochloric acid, concentrated Hydrofluoric acid, concentrated Nitrogen, 99.99% minimum purity, ICP optics purge gas Pipet tips, disposable, for EP-2500 microliter pipet, Rainin Instrument Co., Cat. No. RC-2500 Pipet tips, disposable, for EP-10ML pipet, Ra

21、inin Instrument Co., Cat. No. RC-2500 Pipets, disposable, polyethylene, general purpose, 1.7-mL, VWR, Cat. No. 16001-174 Scandium solution, aqueous, 1000 g/mL, SPEX Industries, Inc., Cat. No. PLSC-2 Standard solutions of metals, Fe, Ni, V, Ca, Mg, Mn, Cr, Sn, Cu, Zn, Ti, Pb, Na, Mo, Co, Al, Cd, K, S

22、r, and Zr solutions of 1000 g/mL concentrations, SPEX Industries, Inc., Cat. Nos. PLFE-2, PLNI-2, PLV-2, PLCA-2, PLMG-2, PLMN-2, PLCR-2, PLSN-2, PLCU-2, PLZN-2, PLTI-2, PLPB-2, PLNA-2, PLMO-2, PLCO-2, PLAL-2, PLCD-2, PLK-2, PLSR-2X, and PLZR3-2X respectively Sulfuric acid, concentrated Nitric acid,

23、concentrated Water, ASTM D 1193 Type I reagent grade Procedure CAUTION: All steps involving additions of acids and heating of samples must be performed in a properly operating fume hood, and appropriate personal protective equipment must be worn. See the MSDS and local regulations for each material

24、used. The analyst is expected to be familiar with general laboratory practices, the technique of ICP-OES, and the equipment being used. Preparation of Standards Due to the linear response of the ICP, single point standards are used. Prepare four stock standard solutions at the 50-g/mL level, labeled

25、 as Stock Standards 2 through 5. This labeling follows SPEX numbering convention, wherein standard number 1 is used for rare earth elements, which are not addressed in this method. 4 of 11 714-07 Four different calibration standards are prepared to ensure solubility and minimize spectral overlap int

26、erferences. 1. Label each of four 500-mL polypropylene volumetric flasks as Stock Standard, the number (2 through 5), 50 g/mL, and list the elements in the solution, see Table 2. 2. Pipet 25 mL of the commercial 1000 g/mL standard solutions of the elements listed in Table 2 into their respective vol

27、umetric flasks. Table 2 Elements Contained in the Stock Standard Solutions Std. 2 Std. 3 Std. 4 Std. 5 Aluminum (Al) Tin (Sn) Molybdenum (Mo) Potassium (K) Cadmium (Cd) Titanium (Ti) Sodium (Na) Calcium (Ca) Zirconium (Zr) Strontium (Sr) Chromium (Cr) Cobalt (Co) Copper (Cu) Iron (Fe) Lead (Pb) Magn

28、esium (Mg) Manganese (Mn) Nickel (Ni) Vanadium (V) Zinc (Zn) 3. Dilute to mark with water and mix well. 4. Label an additional 500-mL polypropylene volumetric flask as Scandium Stock Standard, 100 g/mL 5. Pipet 50 mL of the commercial 1000 g/mL scandium standard solution into the labeled 500-mL poly

29、propylene volumetric flask. 6. Dilute to mark with water and mix well. Prepare the five Calibration Standard Solutions as follows: 1. Label each of four 100-mL polypropylene volumetric flasks as Calibration Standard, the number (2 through 5), 10 g/mL, and list the elements in the solution. Label a f

30、ifth 100-mL polypropylene volumetric flask as Calibration Blank. 2. Pipet 20 mL of the four Stock Standard Solutions into their respective 100-mL polypropylene volumetric flasks. 3. Pipet 5 mL of concentrated sulfuric acid into each of the five volumetric flasks. 4. Pipet 5 mL of the 100 g/mL Scandi

31、um Stock Standard into each of the five flasks. 5. Dilute to mark with water and mix well. The Calibration Standard Solutions contain 10 g/mL of the elements and 5 g/mL of scandium internal standard, in 5% of sulfuric acid to match the matrix of the samples. 5 of 11 714-07 Preparation of Spectromete

32、r Start up the ICP-OES, ignite the plasma according to the manufacturers recommendations, and allow a minimum of 30 minutes before starting the analysis. When recommended by the manufacturer, perform a wavelength calibration prior to the start of the analysis. Aspirate the standards and blank to est

33、ablish response factors prior to aspiration of the samples. Table 3 lists recommended wavelengths to be used for the analyses. Table 3 Recommended Wavelengths Element , nm Element , nm Aluminum 396.152 Manganese 257.610 Cadmium 214.438 Molybdenum 202.030 Calcium (high level) 422.673 Nickel 231.604 C

34、alcium (low level) 393.366 Potassium 766.490 Chromium 206.149 Scandium 424.683 Cobalt 238.892 Sodium 589.592 Copper 324.754 Strontium 460.739 Iron (high level) 273.955 Tin 189.989 Iron (low level) 238.204 Titanium 323.452 Lead 220.353 Vanadium 292.402 Magnesium (high level) 279.079 Zinc 206.200 Magn

35、esium (low level) 279.553 Zirconium 343.823 Sample Preparation Samples are analyzed on an as received (AR) basis unless otherwise specified. However, for samples containing large amounts of carbon and/or organics the samples may be analyzed on a volatile free (VF) basis. If a sample is to be analyze

36、d volatile free, weigh portions of the sample for this test and for LOI at 500C at the same time. Analyze the LOI aliquot by UOP Method 954, “Loss on Ignition (LOI) for Fresh, Regenerated, Used, and Spent Catalysts, Catalyst Supports, and Adsorbents.” Samples that are wet with water are dried overni

37、ght at 105C. Sample homogeneity is critical to obtain reproducible results. For samples containing or composed of large, heterogeneous particles, pulverize the sample in a mixer mill to a consistency of approximately 80 mesh or finer. In cases where only a small amount of sample is available use a m

38、ortar and pestle or alternative grinder vessels. 1. Weigh, to the nearest 0.1 mg, approximately 0.4 g of sample into a tared 250 mL Teflon beaker. For convenience, dry, free-flowing samples may be weighed using a weighing scoop, and then transferred into the beaker. 2. Add 10 mL of water and 10 mL o

39、f concentrated sulfuric acid to the beaker. Slowly add 10 mL of concentrated hydrofluoric acid from a polypropylene graduated cylinder, swirl to mix the contents of the beaker. 3. Place the uncovered beaker on a 150C hot plate. Heat until white fumes of sulfuric acid appear. Remove the beaker from t

40、he hot plate and allow it to cool. 6 of 11 714-07 4. If the solution in the beaker is black or dark brown, or if it contains particulate matter, it may contain organics and/or carbon. Decompose by adding a few drops of concentrated nitric acid and heating on the hot plate until white fumes of sulfur

41、ic acid begin to evolve. Remove the beaker from the hot plate and allow it to cool. 5. If the solution in the beaker contains no particulate matter, proceed to the next step. If any particulates remain, add approximately 20 mL of concentrated hydrochloric acid and 1 mL of nitric acid using graduated

42、 cylinders, cover with a Teflon watch glass and return the beaker to the hot plate. Boil gently until the solution is clear. Remove the beaker from the hot plate and allow it to cool. See Note 2. 6. Quantitatively transfer the contents of the beaker to a 200-mL polypropylene volumetric flask, rinsin

43、g the beaker and watch glass several times with water. 7. Using the Rainin pipet, add the appropriate amount of scandium standard for desired level of standard, typically 10 mL for 5 ppm. 8. Dilute to the mark with water and mix well. The prepared sample solutions are appropriate for the determinati

44、on of minor and trace concentrations of elements in the sample. To determine major (matrix) elements in the sample, a further 20:1 dilution is necessary. 1. Pipet 10 mL of the prepared sample solution into a 200-mL polypropylene volumetric flask. 2. To restore the acid matrix, add 9.5 (or 10) mL of

45、concentrated sulfuric acid. 3. To restore the internal standard level, using a Rainin pipet, add 9.5 mL of the Scandium Stock Standard. 4. Dilute to mark with water and mix well. Sample Analysis Follow the spectrometric procedure as described under Preparation of Spectrophotometer. Following aspirat

46、ion of the standards and blank, and instrument calibration, enter the appropriate weight per volume for the sample into the data system, and aspirate the samples. The computer will calculate the mass-% metal in the sample after pretreatment, as described in Sample Preparation, and print the result.

47、Calculations If the results are to be reported as received, disregard Equation 1 and continue to the next paragraph. If the results are to be reported on a volatile free basis, correct the mass of sample used as shown in Equation 1. W =( )100L100M (1) where: L = LOI from UOP Method 954, mass-% M = m

48、ass of sample as received, g W = mass of sample used in calculation 100 = percent The calculations are normally performed by the data system after the analyst enters the appropriate values for weights and dilution volumes. 7 of 11 714-07 Report results to the nearest 0.01 mass-%, but no greater than

49、 three significant figures. Also report whether the sample was analyzed as received (AR) or volatile free (VF). Notes 1. Silicon cannot be determined by this method because silicon dioxide is insoluble in the acids used. Any silicon present is removed by boiling with hydrofluoric acid to avoid the necessity of filtering the sample. If the concentration of silicon is desired an alternative sample preparation technique, such as lithium tetraborate fusion, not described herein, may be used. 2. Barium can