UOP 1005-2014 Trace Metals in Organics by ICP-MS.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. SAFETY DATA SHEETS (SDS) OR EXPERIMENTAL SAFETY DATA SHEETS (ESDS) FOR ALL OF THE MATERIALS USED IN THIS PROCEDURE SHOULD BE REVIEWED FOR SELECTION OF THE APPROPRIATE PERSONAL PROTECTION EQUIPMENT (PPE). COPYRIGHT 2014 UOP LLC. All rights reserved. Nonconfidential UOP Met

3、hods 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 FAX, or 610.832.9585 PHONE. Trac

4、e Metals in Organics by ICP-MS UOP Method 1005-14 Scope This method is for determining the concentrations of aluminum (Al), arsenic (As), calcium (Ca), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), gallium (Ga), lead (Pb), lithium (Li), magnesium (Mg), manganese (Mn), molybdenum

5、(Mo), nickel (Ni), palladium (Pd), phosphorus (P), platinum (Pt), potassium (K), sodium (Na), strontium (Sr), tin (Sn), titanium (Ti), vanadium (V), zinc (Zn), and zirconium (Zr), in organic matrices such as crude petroleum, asphalts, vacuum tower bottoms, vacuum gas oils, atmospheric gas oils, dies

6、el and jet fuels and their blending components, pyrolysis oils, and fatty acid derivatives by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The lower limits of quantitation for the above elements, are listed in Table 1. Determination of additional elements is possible if they are compatible

7、 with other analytes during digestion. Table 1 Lower Limits of Quantitation, mg/kg (mass-ppm) Al 0.02 K 0.03 Pd 0.01 As 0.01 Li 0.01 Pt 0.01 Ca 0.03 Mg 0.02 Sn 0.01 Cd 0.01 Mn 0.01 Sr 0.01 Co 0.01 Mo 0.01 Ti 0.03 Cr 0.01 Na 0.06 V 0.01 Cu 0.01 Ni 0.01 Zn 0.01 Fe 0.02 P 0.50 Zr 0.01 Ga 0.01 Pb 0.01 A

8、lternatively, many of the elements listed above can be determined using UOP Method 389, “Trace Metals in Organics by ICP-OES.” Some of the elements listed above may be analyzed by Atomic Absorption Spectroscopy (AAS). See UOP Method 391, “Trace Metals in Petroleum Products or Organics by AAS,” for s

9、pecific metals and their range of quantitation. Metals known to be non-volatile may be analyzed by UOP Method 407, “Trace Metals in Organics by Dry Ashing - ICP-OES.” Many of these elements can be determined in kerosene using ASTM Method D7111, “Determination of Trace Elements in Middle Distillate F

10、uels by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES).” References ASTM Specification D1193, “Reagent Water,” www.astm.org 2 of 11 1005-14 ASTM Method D7111, “Determination of Trace Elements in Middle Distillate Fuels by Inductively Coupled Plasma Atomic Emission Spectrometry (IC

11、P-AES),” www.astm.org ASTM Practice D7455, “Sample Preparation of Petroleum and Lubricant Products for Elemental Analysis,” www.astm.org ASTM Practice D7876, “Sample Decomposition Using Microwave Heating (With or Without Prior Ashing) for Atomic Spectroscopic Elemental Determination in Petroleum Pro

12、ducts and Lubricants,” www.astm.org UOP Method 389, “Trace Metals in Organics by ICP-OES,” www.astm.org UOP Method 391, “Trace Metals in Petroleum Products or Organics by AAS,” www.astm.org UOP Method 407, “Trace Metals in Organics by Dry Ashing - ICP-OES,” www.astm.org UOP Method 999, “Precision St

13、atements in UOP Methods,” www.astm.org Outline of Method The sample is treated intially with water, then nitric and hydrofluoric acids, to reduce the volatility of some of the metals. Then the samples are digested. The digestate is quantitatively transferred to a polypropylene flask using purified w

14、ater. Scandium and bismuth are added as internal standards and the mixture is diluted to the desired volume. The concentrations of elements in the resulting solutions are determined by ICP-MS. Apparatus References to catalog numbers and suppliers are included as a convenience to the method user. Oth

15、er suppliers may be used. Balance, readable to 0.0001 g Beaker, PTFE, 600-mL, Fisher Scientific, Cat. No. 02-586-1K Bottles, polypropylene, narrow mouth, screw cap, 125-mL, VWR, Cat. No. 16067-066 Bottle, wash, VWR, Cat. No. 2402-0500, for deionized water Cover, PTFE, Milestone, Cat. No. MCL0435, wi

16、th o-ring, Cat. No. OR0138, used to cover the stainless steel vessel in the microwave oven Cylinders, graduated, Class B, 5-, 10-, 25-, and 100-mL, VWR, Cat. Nos. 14201-610, -462, -364, and -718, respectively Flasks, volumetric, polypropylene, Class B, 25-, 50-, 100-, and 1000 mL, VWR, Cat. Nos. 830

17、08-964, -974, -984, and 83009-008, respectively; several of each required Fume hood Hot plate, VWR, Cat. No. 11301-006 ICP-MS, PerkinElmer, DRC-e, equipped with an AS10 autosampler, or equivalent newer version Microwave oven, 15-vessel capacity, with closed digestion vessels, quartz tubes and lids,

18、CryoLab chiller, and computer, Milestone, UltraWAVE, or equivalent newer version Pipet, automatic, 10-100-L, VWR, Cat. No. 89079-968; calibrated and/or certified according to manufacturers recommendations 3 of 11 1005-14 Pipet, automatic, 100-1000-L, VWR, Cat. No. 89079-974; calibrated and/or certif

19、ied according to manufacturers recommendations Pipet, electronic, 1-10-mL, EDP 3-Plus, Rainin, Cat. No. SE3-10mL; calibrated and/or certified according to manufacturers recommendations Regulator, argon or nitrogen, two-stage, high purity, delivery pressure range 30-700 kPa (4-100 psi), Matheson Tri-

20、Gas, Model 3122-580 Timer, capable of timing two hours, VWR, Cat. No. 62344-440 Watch glass, PTFE, 125-mm, Fisher Scientific, Cat. No. 02-617-1F Reagents and Materials References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Unless ot

21、herwise specified, references to water mean deionized water. Argon, 99.995% minimum purity Bismuth, indium, and scandium stock solution, aqueous, 100-g/mL. To prepare 50 mL, pipet 0.5 mL of the 10,000- g/mL scandium, 5 mL of the 1000- g/mL indium, and 5 mL of the 1000- g/mL bismuth metal solutions i

22、nto a 50-mL volumetric flask. Fill to the mark with deionized water. Cap and invert several times to mix. The solution should remain stable for two months. Bismuth, indium, and scandium internal standard solution, 10-g/mL. To prepare 100 mL, pipet 10.0 mL of the 100-g/mL scandium, indium, and bismut

23、h metal stock solution into a 100-mL volumetric flask. Fill to the volume mark with deionized water and mix. Store in a 125-mL polypropylene bottle. The solution should remain stable for two months. Bismuth metal solution, aqueous, 1000-g/mL, SPEX CertiPrep, Inc., Cat. No. PLBI-2, for use as an inte

24、rnal standard Cleaning compound, Alconox detergent, VWR, Cat. No. 21835-032 Gloves, neoprene/natural rubber, VWR, Cat. No. 32917-212 (size 10) Gloves, Viton, VWR, Cat. No. 89236-768 (size 10) Hydrofluoric acid, concentrated, trace metals grade, VWR, Cat. No. EM-HX0628-7 Hydrogen peroxide, 29-32%, VW

25、R, Cat. No. VW3690-5 Indium metal solution, aqueous, 1000-g/mL, SPEX CertiPrep, Inc., Cat. No. PLIN2-2X, for use as a stabilizer Lubricant, dry spray silicone or PTFE, W. W. Grainger, Cat. No. 4JB33, or local supply Nitric acid, concentrated, trace metals grade, VWR, Cat. No. EM-NX0408-2 Nitric acid

26、, 2%. Pipet 20 mL of concentrated nitric acid into a 1000-mL containing 800-mL of deionized water; fill to mark with deionized water, and invert several times to mix. Nitrogen, 99.995% minimum purity, optional, see Microwave Digestion, Step 6 O-rings, replacement, for microwave oven, Milestone, Cat.

27、 No. OR0159 O-ring, top of chamber, replacement, Milestone, Cat. No. OR0170 Pipet, dropping, VWR, Cat. No. 52950-206 Pipet tips, 10 mL, Rainin, Cat. No. RC-10 mL 4 of 11 1005-14 Pipet tips, 1-200-L VWR, Cat. No. 53508-810 Pipet tips, 100-1250-L, VWR, Cat. No. 53508-922 Scandium metal solution, aqueo

28、us, 10,000-g/mL, SPEX CertiPrep, Inc., Cat. No. PLSC2-3X, for use as an internal standard Standard metal solutions, Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Pd, Pt, Sn, Sr, Ti, V, Zn, and Zr solutions of 1000-g/mL concentrations, SPEX CertiPrep, Inc., Cat. Nos. PLAL1-2,

29、PLAS2-2, PLCA1-2, PLCD2-2, PLCO2-2, PLCR1-2, PLCU2-2, PLFE2-2, PLGA2-2, PLK1-2, PLLI2-2, PLMG2-2, PLMN2-2, PLMO2-2, PLNA2-2, PLNI2-2, PLP9-2, PLPB2-2, PLPD3-2, PLPT3-2, PLSN5-2, PLSR2-2, PLTI9-2, PLV2-2, PLZN2-2, and PLZR2-2, respectively Sulfuric acid, concentrated, trace metals grade, VWR, Cat. No

30、. EM-SX1248-6 Towels, paper, disposable, local supply Vials, autosampler, 50 mL, with caps, PerkinElmer, Cat. No. BO193234 Vials, PTFE, 15-mL, Milestone, Cat. No. HB00086, with caps, Cat. No. DD00134 Water, deionized, ASTM D1193 Type III reagent grade water, unless otherwise specified Water, hot, ta

31、p Wipers, Kimwipes Ex-L, VWR, Cat. No. 21905-026 The following materials are not required to perform the analyses described herein and are not cited in the Procedure portion of the method. However, they may be useful for reference purposes, for verification of instrument performance, or as an aid in

32、 instrument maintenance. The multi-element standard, diluted, was used to develop part of the precision statement. Kerosene solvent, metals free, VWR, Cat. No. AA36447-K7 or SPEX, Cat. No. KER-BLK-G Reference material, SPEX CertiPrep 23 Multi-Element Standard, 100-g/g (mg/kg) each, SPEX CertiPrep, I

33、nc., Cat. No. S23 1004. Dilute by weight in kerosene solvent to 10 g/g. Procedure The analyst is expected to be familiar with general laboratory practices, the technique of ICP-MS, and the equipment being used. Additional information regarding sample preparation may be found in ASTM Practice D7455,

34、“Sample Preparation of Petroleum and Lubricant Products for Elemental Analysis.” Additional information regarding the use of microwave digestion for sample decomposition may be found in ASTM Practice D7876, “Sample Decomposition Using Microwave Heating (With or Without Prior Ashing) for Atomic Spect

35、roscopic Elemental Determination in Petroleum Products and Lubricants.” Dispose of all supplies and samples in an environmentally safe manner according to applicable regulations. CAUTION: All subsequent steps involving additions of reagents and heating of samples must be performed in a properly oper

36、ating fume hood, and appropriate personal protective equipment must be worn. See the safety data sheet (SDS) and any local requirements for each material used. Preparation of Standards Standards are required for each element to be determined. They are prepared to contain a number of elements with co

37、mpatible chemistries. Stock standard solutions are prepared first, from which lower level, matrix matched, calibration standard solutions are then prepared. 5 of 11 1005-14 Preparation of Stock Standard Solutions Prepare stock standard solutions of 10-g/mL concentration of each element (except Ca 20

38、-g/mL and P 40-g/mL) as follows: 1. Pipet 1.0 mL each of the Al, As, Ca (2.0 mL), Cd, Cr, Co, Cu, Fe, Ga, Mg, Mn, Ni, and Pb, 1000-g/mL commercial stock standards into a 100-mL polypropylene volumetric flask. Dilute to the mark with deionized water. Label as Stock Standard A. The solution should rem

39、ain stable for two months. 2. Pipet 1.0 mL each of the Pd, Pt, Sn, V, and Zn 1000-g/mL commercial stock standards into a second 100-mL polypropylene volumetric flask. Dilute to the mark with deionized water. Label as Stock Standard B. The solution should remain stable for two months. 3. Pipet 1.0 mL

40、 each of the Mo, P (4.0 mL) Ti, and Zr, 1000-g/mL commercial stock standards into a third 100-mL polypropylene volumetric flask. Dilute to the mark with deionized water. Label as Stock Standard C. The solution should remain stable for two months. 4. Pipet 1.0 mL each of the K, Li, Na, and Sr 1000-g/

41、mL commercial stock standards into a fourth 100-mL polypropylene volumetric flask. Dilute to the mark with deionized water. Label as Stock Standard D. The solution should remain stable for two months. 5. Pipet 1.0 mL of the K 1000-g/mL commercial stock standard into a fifth 100-mL polypropylene volu

42、metric flask. Dilute to the mark with deionized water. Label as Stock Standard E. The solution should remain stable for two months. Cleaning of PTFE Vials and Caps Clean the PTFE vials and caps as follows: 1. Place PTFE vials and caps in a 600-mL beaker, cover with 2% nitric acid, and place a watch

43、glass on top of the beaker. 2. Place the beaker on a hot plate. Set the hot plate to 200 C and bring to a boil. Adjust the temperature of the hot plate to maintain a slow boil. Boil for two hours. 3. Remove the beaker from the hot plate and allow to cool. 4. Decant the acid and dispose of it in an e

44、nvironmentally safe manner according to applicable regulations. 5. Rinse the PTFE vials, caps, beaker, and watch glass with deionized water, and air dry. 6. Store the vials and caps in the beaker, covered with the watch glass until needed. Microwave Digestion The blank and the reference are digested

45、 in the same manner as the samples. 1. Weigh 0.20-0.25 g of each sample to the nearest 0.0001 g into the previously cleaned and air dried vials. Using a pipet or graduated cylinder, add 1 mL of water. Using a graduated cylinder, add 3 mL of concentrated nitric acid (HNO3). Using a plastic dropping p

46、ipet, add three drops of hydrofluoric acid (HF) to the PTFE vials. 6 of 11 1005-14 2. Prepare an additional three vials as digestion acid blanks by adding 1 mL water, 3 mL concentrated nitric acid and three drops of hydrofluoric acid to each of the pre-cleaned, air dried PTFE vials. One vial is used

47、 for preparing the blank, two are used for standard preparation. This is to ensure matrix matching with the samples. The addition of hydrofluoric acid is used to stabilize tin (Sn). If the results for tin (Sn) are inconsistent, increase the amount of hydrofluoric acid (HF) to five drops. 3. Close th

48、e digestion vessels and place them into the sample holder. 4. Set up the microwave as described below. Refer to the UltraWAVE Operator Manual for details. Add the basic load/absorption media as follows: Using graduated cylinders, add 130 mL of water, 5 mL of 30% hydrogen peroxide, and 2 mL of sulfur

49、ic acid into the PTFE vessel that goes into the stainless steel pressure vessel. This acts as absorption media. Ensure that all o-rings are properly cleaned and greased. 5. Check the water level in the CryoLab chiller. 6. Turn on the gas (nitrogen or argon), CryoLab chiller, computer, and UltraWAVE. 7. Program the system using the settings shown in Table 2. Other conditions may be used provided they produce equivalent results. Table 2 Digestion Conditions Nr. t(min) E (w) T1 C T2 C P 1 00:30:00 1500 230 60 150 2 00:40:00 1500 230 60 150 Nr.