# Vanadium Oxides (7504)

​VANADIUM OXIDES
(1): V2O5 MW: (2): V2O3 (3): NH4VO3
(1): 181.88 (2): 149.88 (3): 116.99
METHOD: 7504, Issue 2
CAS: (1) 1314-62-1 (2) 1314-34-7 (3) 7803-55-6
7504
RTECS: (1) YW2450000 (dust) (1) YW2460000 (fume) (2) YW3050000 (3) YW0875000
EVALUATION: PARTIAL
C 0.5 mg/m 3 (as V) (V 2O 5 Dust); C 0.1 mg/m 3 (as V) (V 2O 5 Fume); 1 mg/m 3 (FeV) NIOSH: C 0.05 mg/m 3/15 min (as V 2O 5) ACGIH: 0.05 mg/m 3 (respirable, as V 2O 5) OSHA:
Issue 1: 15 August 1987 Issue 2: 15 August 1994
PROPERTIES: solids; MP 658 °C (1); MP 1967 °C (2)
SYNONYMS: (1): vanadic anhydride; vanadium pentoxide; (2): vanadic oxide; vanadium sesquioxide; vanadium trioxide. SAMPLING SAMPLER:
FLOW RATE:
MEASUREMENT
CYCLONE + FILTER (10-mm cyclone or Higgins-Dewell (HD) + 5-µm PVC membrane) HD cyclone: 2.2 L/min nylon cyclone: 1.7 L/min
VOL-MIN: -MAX:
200 L @ 0.5 mg/m 3 1000 L
SHIPMENT:
routine
SAMPLE STABILITY:
stable
BLANKS:
2 to 10 field blanks per set
BULK SAMPLE:
X-RAY POWDER DIFFRACTION
ANALYTE:
vanadium pentoxide, vanadium trioxide, or ammonium metavanadate
SAMPLE PREPARATION:
Cu target X-ray tube optimize for intensity; 1° 2 θ slit graphite monochromator scintillation detector integrated intensity with background subtraction slow step scan (10 seconds/0.02° 2 θ)
CALIBRATION:
standard suspensions deposited on Ag filter
RANGE:
0.1 to 2 mg V per sample
of
analytes
ESTIMATED LOD: Table 1
RANGE STUDIED:
(1): 0.8-2.6 mg/m 3; (2): 0.2-2.6 mg/m 3 [1]
BIAS:
Table 1
ˆ ): OVERALL PRECISION (S rT
dissolve filter in tetrahydrofuran; redeposit on Ag filter
XRD:
high-volume respirable (preferred) or settled dust to identify interferences
ACCURACY
ACCURACY:
METHOD:
PRECISION (Sr):
Table 1
Table 1 ± 26 to 62%
APPLICABILITY: The working range is 0.2 to 4 mg/m 3 (as V) for a 500-L air sample. The method will determine V 2O 5, V2O 3, and NH 4VO 3 separately on the same sample. INTERFERENCES: α-Quartz (likely to be found in mineral samples) interferes (Table 1) but alternative diffraction lines are available. Most other compounds likely to be in the sample do not interfere [1].
OTHER METHODS: This replaces P&CAM 364 [2]. Methods S391 (Vanadiaum by graphite atomizer AAS) and 7300 (Elements by ICP-AES) determine total V.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 2 of 10 REAGENTS: 1.
2. 3. 4. 5. 6.
EQUIPMENT:
V2O 5, V 2O 3 or NH 4VO 3 (≥99%). Grind in freezer mill. Sieve through 10-µm sieve in isopropanol (for V 2O 3 or NH 4VO 3) or acetonitrile (for V 2O 5). Dry at 110 °C for one hour. Store in desiccator. Tetrahydrofuran (THF), reagent grade.* Isopropanol, reagent grade. Acetonitrile, reagent grade. Glue or tape for securing silver filters to XRD holders. Desiccant.
1. Sampler: a. Filter: 37-mm diameter, 5.0-µm pore size, polyvinyl chloride filter supported with backup pad in a two-piece, 37-mm cassette filter holder (preferably, conductive) held together by tape or cellulose shrink band. NOTE: Test PVC filter for THF digestion (see Step 4). b. Cyclone: 10-mm nylon or Higgins-Dewell (HD), or equivalent. c. Sampling head holder: Holder must keep the cassette, cyclone, and coupler together rigidly so that air enters only at the cyclone inlet. 2. Bulk sampler: PVC membrane filter, 37-mm, 5-µm pore size in two-piece filter cassette. Sample closed face at 3 L/min. 3. Sampling pumps: HD cyclone, 2.2 L/min; nylon cyclone, 1.7 L/min; and bulk sampler, 3 L/min. 4. Filters, silver membrane, 25-mm diameter, 0.45-µm pore size (Osmonics, Inc., Nuclepore, Poretics, or equivalent). 5. X-ray powder diffractometer with copper target X-ray tube, graphite monochromator, and scintillation detector. 6. Reference specimen (mica, Arkansas stone or other stable standard. Source: Gem Dugout, State College, PA, 16801) for data normalization. 7. Filtration apparatus and side arm vacuum flask, with 25-mm filter holders. 8. Sieve, 10-µm, for wet-sieving. 9. Centrifuge tubes, wide-mouth, 40-mL. 10. Ultrasonic bath or probe. 11. Analytical balance (0.01 mg). 12. Magnetic stirrer with thermally-insulated top. 13. Bottles, reagent, 1-L, with ground glass stoppers. 14. Drying oven. 15. Polyethylene wash bottle. 16. Desiccator. 17. Pipets, TD, 2- to 25-mL.
SPECIAL PRECAUTIONS: THF is extremely flammable and should be used in a fume hood.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 3 of 10 SAMPLING: 1. 2.
3.
Calibrate each personal sampling pump with a representative sampler in line. Sample at 1.7 ± 5% L/min with a nylon cyclone or 2.2 ± 5% L/min with an HD cyclone for a total sample size of 200 to 1000 L. Do not exceed 2 mg dust loading on the filter. NOTE: Do not allow the sampler assembly to be inverted at any time. Turning the cyclone to more than 90 °C from vertical may deposit over-sized material from the cyclone body onto the filter. Obtain an area high-volume bulk sample in the vicinity of the personal sampling area.
SAMPLE PREPARATION: 4.
5.
6.
Place sample filter in a centrifuge tube. Add 10 mL THF. Place centrifuge tube in ultrasonic bath for 10 min. NOTE: The filter should dissolve almost instantaneously. Mount a silver filter in the filtration apparatus. Attach the funnel securely over the entire filter circumference. With no vacuum, pour 2 to 3 mL THF onto the filter. Pour the sample suspension from the centrifuge tube into the funnel. Rinse centrifuge tube twice with 5-mL portions of THF, adding rinses to the funnel, and apply vacuum. Control filtration rate to keep liquid level near top of funnel during filtering. Do not wash the walls or add THF to the funnel when the liquid level is lower than 4 cm above the filter. Leave vacuum on after filtration for sufficient time to dry the filter. Transfer filter with forceps to sample holder for XRD analysis.
CALIBRATION AND QUALITY CONTROL: 7.
8.
9.
Select six silver membrane filters as media blanks, randomly from the same box of filters to be used for depositing the samples. Mount each media blank on the filtration apparatus and apply vacuum to draw 5 to 10 mL THF through the filter. Remove, let dry and mount on XRD holders. NOTE: These will be used to test for sample self-absorption. Prepare standard suspensions. a. Weigh 10- and 50-mg portions of the dry analytes to the nearest 0.01 mg. Quantitatively transfer to 1-L glass-stoppered bottles. Add 1.00 L acetonitrile (for V 2O 5) or isopropanol (for V2O 3 or NH 4VO 3). b. Disperse the powder in the liquid using an ultrasonic probe or bath for 20 min. Immediately move the flask to a magnetic stirrer and add a stirring bar to the suspension. Allow the solution to return to room temperature before withdrawing aliquots. Prepare a series of standard filters over the range 0.05 to 2 mg V per sample. a. Mount a filter on the filtration apparatus. Wet the filter with ca. 3 mL of acetonitrile (for V2O 5) or isopropanol (for V 2O 3 or NH 4VO 3). b. Turn off the stirrer and shake the bottle vigorously by hand. Immediately remove the lid and withdraw an aliquot (2 to 25 mL) from the center of the suspension. Do not adjust the volume in the pipet by expelling part of the suspension. If more than the desired aliquot is withdrawn, return all of the suspension to the bottle, rinse and dry the pipet, and take a new aliquot. c. Transfer the aliquot from the pipet to the funnel. Keep the tip of the pipet near the surface but not submerged in the suspension. Rinse the pipet with ca. 5 mL of acetonitrile (for V2O 5) or isopropanol (for V 2O 3 or NH 4VO 3), draining the rinse into the funnel. Repeat the rinse three more times. d. Apply vacuum and rapidly filter the suspension. Leave vacuum on until filter is dry. Do not wash down sides of funnel after deposit is in place (to avoid rearranging the material on the filter). e. Transfer the filter to the XRD sample holder.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 4 of 10 10.
11.
Perform step scans on the standards and reference specimen using the same conditions as for samples. Use steps 12 and 13 to determine normalized intensity, , for each peak measured. Use exactly the same normalization factor, N, as for samples (step 13). Prepare calibration graph ( vs. mg of each standard). Determine slope, m (counts/µg). NOTE 1: The intercept with the axis should be ca. zero. A large negative intercept indicates an error in determining background (e.g., incorrectly measuring the baseline, or interference by another phase at the angle of background measurement). A large positive intercept indicates an error in determining the baseline or that an impurity is included in the measured peak. NOTE 2: Poor repeatability at a given level indicates problems in the sample preparation technique and new standards should be made. Eliminate curvature with absorption corrections based on the mass absorption coefficient of the analyte (step 15, or from Tables 2 through 4).
MEASUREMENT: 12.
13.
Obtain a qualitative X-ray diffraction scan (broad 2 θ range) of high-volume sample to determine the presence of interferences. NOTE: If quantitative analysis is to be done on the bulk sample, wet-sieve it first through a 10-µm sieve. Mount the filter (sample, standard, or blank) in the XRD instrument and perform the following: a. Determine net intensity, I or , of the reference specimen before filter is scanned. Select a convenient scale factor, N, which is approximately equivalent to the net count for the reference specimen peak; use this for all analyses. b. Step-scan the most intense, interference-free diffraction peak of each compound to be determined, integrating the counts. NOTE: Useful analytical lines for the analytes are given in Table 1. Use strongest line of the analyte which does not have a matrix interference. Avoid lines in the proximity of Ag (JCPDS #4-0783 [3]) and AgCl (JCPDS #31-1238 [4]) (the latter often exists on the surface of silver filters). c. Measure the background on each side of the peak for one-half the time used for peak scanning. Add the counts from each side to obtain total (average) background. d. Calculate net intensity, I x, (different between peak integrated count and total background count). e. Calculate and record the normalized intensity for the analyte peak on each sample and standard:
f.
For each media blank, determine the net count for the analyte diffraction peak. Calculate the average normalized intensity, Î b, for the 6 media blanks. Determine net count, I Ag, of an interference-free silver peak on the filter following the same procedure. Scan times should be shorter for the silver peak (e.g., about 5% of scan times for analyte peaks) and should be consistent throughout the method. For each media blank, determine the net count for the silver peak. Calculate the average value, , for the 6 media blanks. NOTE: Normalizing to the reference specimen intensity compensates for long-term drift in X-ray tube intensity. If intensity measurements are stable, the reference specimen may be run less frequently. In this case, the net intensities of the analyte, blank, and silver peaks (I x, I b, and I Ag) should be normalized to the most recently measured reference intensity.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 5 of 10 14.
Scan each field blank over the same 2 θ range used for the analyte and silver peaks. The analyte peak should be absent. The normalized intensity of the silver peak of the field blanks should match that of the media blanks. NOTE: These analyses serve only to verify that contamination of the filters has not occurred.
CALCULATIONS: 15.
Calculate absorption correction factors (Tables 2, 3, and 4) [5]:
where: R = (sin θAg)/(sin θx) and T = / = transmittance of sample. 16.
Calculate concentration, C, of analyte in air volume sampled, V (L):
where:
Îx = normalized intensity of sample peak Îb = normalized intensity of blank m = slope of calibration graph, counts/µg
EVALUATION OF METHOD: VANADIUM PENTOXIDE: The V 2O 5 method was evaluated [1] with both spiked and generated samples of V 2O 5. With the spiked samples, using the 31.05° line and loadings of 433 to 699 µg/filter, the overall SˆrT was 8.3% with an average bias of -7.3%. Five sets of generated samples, ranging from 184 to 2400 µg V 2O 5 per filter, gave an average bias of 10.12% with a pooled Sr of 6.9%. The generated samples used an aerosol which had been sized with a cyclone with characteristics similar to the 10-mm nylon cylone; however, individual 10-mm nylon cyclones on the cassettes were not used. VANADIUM TRIOXIDE: The method was evaluated [1] with both spiked and generated samples of V2O 3. With the spiked samples, and the 24.39° line and loadings of 107 to 321 µg per filter, the overall Sr was 8.2% with an average bias of 12.2%. Five sets of generated samples, from atmospheres of 0.24 to 2.57 mg V 2O 3/m 3, gave an average bias of -10.1% with a pooled Sr of 13.4% (24.39° line). As above, the samples were generated by using an aerosol, which had been sized by means of a cyclone with characteristics similar to the 10-mm nylon cylone; however, individual 10-mm nylon cyclones on the cassettes were not used. AMMONIUM METAVANADATE: The method was evaluated [1] with spiked NH 4VO 3 samples over the range of 109 to 277 µg NH 4VO 3 per filter, and with samples generated as described above, with atmospheres of 0.037 to 0.435 mg/m 3 of NH 4VO 3. The 18.10 °2 θ line provided an overall SˆrT of 26.3%, with a bias of -10.2% over the generation range. The stability of the compound is critical and analysis should occur within two weeks of sampling, unless refrigeration storage is employed. Sampling is quantitative using the two-filter technique described.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 6 of 10 For the analytes, biases of spiked samples were determined by assuming the volume of suspension as "true." Biases of generated samples were determined by assuming that the concentration obtained from the ICP-AES analysis of monitor AAWP filters was the "true" concentration. Instrumental imprecision increases with smaller depositions. For low loading levels, higher counting times will increase precision, as should sample spinning. The stated lower limit of quantitation of ca. 100 µg per analyte when the recommended analytical lines were used is an estimate based on numerous spiked and generated sample experiments.
REFERENCES:
[1] [2] [3] [4] [5]
[6] [7]
T. Carsey, "Quantitation of Vanadium Oxides in Airborne Dusts by X-Ray Diffraction," Anal. Chem., 57: 2125-2130 (1985). NIOSH Manual of Analytical Methods, 2nd ed., Vol. 8 (unpublished, 1982). Powder Diffraction File Search Manual, International Centre for Diffraction Data (JCPDS), Swarthmore, PA, 19081, p. 809 (1981). Ibid., p. 810. M. Abell, D. Dollberg, J. Crable, "Quantitative Analysis of Dust Samples from Occupational Environments Using Computer-Automated X-ray Diffraction," in Advances in X-Ray Analysis , Vol. 24, Plenum, p. 37 (1981). E. Bertin: Principles and Practice of X-ray Spectrometric Analysis , 2 nd Ed., Plenum, New York, p. 471 (1975). Criteria for a Recommended Standard...Occupational Exposure to Vanadium, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-222 (1977).
METHOD REVISED BY: Charles Lorberau, NIOSH/DPSE.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 7 of 10 Table 1.
d-space (A)
Characteristics of analytical lines.
Relative Scan Inten- Peak Min Max sity 1 2θ1 2θ 2θ
CaliDetection bration Limit 2 Slope (µg) (ct/µg)
Precision 3 Bias 4 (% SˆrT) (%)
Comments
4.38 4.09 3.40 2.88 2.185
100 35 90 65 17
20.27 21.73 26.21 31.05 41.32
19.4 20.9 25.5 30.3 40.5
20.9 22.4 26.6 31.4 41.6
Vanadium Pentoxide (PDF # 9-0387) 4 205.0 11.5 -28.9 13 57.1 10 54.2 11.3 -22.3 9 73.0 8.3 10.1 28 24.9 -
α-Quartz interf. 20.85 °2 θ α-Quartz interf. 20.85 °2 θ α-Quartz interf. 26.69 °2 θ good weak; V 2O 3 interf. 41.42 °2 θ
3.65 2.70 2.47 2.18 1.83 1.69 1.43
60 80 60 20 25 100 30
24.39 33.18 36.37 41.42 49.83 54.28 65.25 5
24.75 23.5 33.5 32.5 36.8 35.7 41.7 40.6 50.4 49.3 54.5 53.3
Vanadium Trioxide (PDF # 26-278) 6 75.1 14.7 -10.1 5 78.3 16.0 0.0 9 70.6 15.6 14.2 62 11.7 21 30.2 5 91.2 20.7 -10.1
good AgCl interf. 32.32 °2 θ α-Quartz interf. 36.53 °2 θ weak; V 2O 5 interf. 41.32 °2 θ weak good
5.88 4.90 4.14 3.77 3.164 2.912 2.628
50 75 95 40 100 60 45
15.07 18.10 21.46 23.60 28.21 6 30.74 34.12
14.3 17.7 21.0 23.1
1 2 3
4 5 6
Ammonium Metavanadate (PDF # 9-411) 15.4 7 133.8 24.0 11.4 18.2 7 101.4 26.3 -10.2 21.8 10 49.8 13.2 23.9 18 38.5 50.3 30.1 30.9 21 33.9 33.5 34.4 20 36.0 -
good good weak; V 2O 5 interf. 21.73 °2 θ weak; V 2O 5 interf. 41.32 °2 θ AgCl interf. at 27.88 °2 θ weak weak
From Reference [7], p. 979 (g = 1.5418A)°. Reference [6]. SˆrT = (GRSD 2 + 0.1667 .SRSD 2 + .05 2)½, where GRSD is the generated-sample pooled relative standard deviation, and SRSD is the spiked-sample pooled relative standard deviation. This is the estimated relative standard deviation for the total (sampling plus measurement) air-monitoring method. From generated samples. Not evaluated because of an Ag interference at 64.48 °2 θ. Not evaluated because of an AgCl interference at 27.88 °2 θ.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 8 of 10 Table 2.
V 2O 5 Silver
Matrix absorption correction factors for vanadium pentoxide/silver peaks by degrees two-theta.
20.27° 38.12° T 1.00 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.92 0.91 0.90 0.89 0.88 0.87 0.86 0.85 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75
(T) 1.0000 1.0094 1.0189 1.0285 1.0384 1.0483 1.0585 1.0688 1.0794 1.0901 1.1009 1.1120 1.1233 1.1348 1.1465 1.1584 1.1705 1.1828 1.1954 1.2082 1.2213 1.2346 1.2482 1.2620 1.2762 1.2906
26.13° 38.12° f(T) 1.0000 1.0073 1.0147 1.0222 1.0298 1.0375 1.0454 1.0533 1.0614 1.0697 1.0780 1.0865 1.0952 1.1040 1.1129 1.1220 1.1312 1.1406 1.1502 1.1599 1.1698 1.1799 1.1902 1.2006 1.2113 1.2221
31.00° 38.12°
20.27° 38.12°
26.13° 38.12°
31.00° 38.12°
f(T)
T
f(T)
f(T)
f(T)
1.0000 1.0062 1.0124 1.0187 1.0251 1.0317 1.0383 1.0450 1.0518 1.0587 1.0658 1.0729 1.0801 1.0875 1.0950 1.1026 1.1103 1.1182 1.1261 1.1343 1.1425 1.1509 1.1595 1.1682 1.1770 1.1860
0.74 0.73 0.72 0.71 0.70 0.69 0.68 0.67 0.66 0.65 0.64 0.63 0.62 0.61 0.60 0.59 0.58 0.57 0.56 0.55 0.54 0.53 0.52 0.51 0.50 0.49
1.3053 1.3203 1.3356 1.3512 1.3672 1.3835 1.4002 1.4172 1.4346 1.4524 1.4706 1.4892 1.5083 1.5278 1.5478 1.5682 1.5892 1.6107 1.6327 1.6553 1.6784 1.7022 1.7266 1.7516 1.7774 1.8039
1.2332 1.2445 1.2560 1.2677 1.2796 1.2918 1.3043 1.3170 1.3300 1.3432 1.3567 1.3706 1.3847 1.3992 1.4139 1.4291 1.4445 1.4604 1.4766 1.4932 1.5102 1.5277 1.5456 1.5640 1.5828 1.6022
1.1952 1.2046 1.2141 1.2238 1.2337 1.2438 1.2541 1.2646 1.2753 1.2862 1.2973 1.3087 1.3203 1.3322 1.3444 1.3568 1.3695 1.3825 1.3957 1.4094 1.4233 1.4376 1.4522 1.4672 1.4826 1.4984
T = Sample transmittance (see step 15) f(T) = Sample correction factor (see step 15)
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 9 of 10 Table 3.
Matrix absorption correction factors for vanadium trioxide/silver peaks by degrees two-theta.
V 2O 3 Silver
24.39° 38.15° T 1.00 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.92 0.91 0.90 0.89 0.88 0.87 0.86 0.85 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75
f(T) 1.00000 1.00779 1.01571 1.02375 1.03191 1.04021 1.04863 1.05719 1.06589 1.07474 1.08372 1.09286 1.10215 1.11160 1.12122 1.13099 1.14094 1.15107 1.16137 1.17186 1.18255 1.19342 1.20450 1.21579 1.22729 1.23902
33.18° 38.15°
36.37° 38.15°
54.28 38.15°
24.39° 38.15°
f(T)
f(T)
f(T)
T
1.00000 1.00576 1.01161 1.01753 1.02354 1.02964 1.03583 1.04211 1.04848 1.05494 1.06151 1.06817 1.07494 1.08181 1.08879 1.09589 1.10309 1.11042 1.11786 1.12543 1.13313 1.14096 1.14892 1.15702 1.16526 1.17365
1.00000 1.00527 1.01061 1.01603 1.02152 1.02709 1.03274 1.03847 1.04429 1.05019 1.05617 1.06225 1.06842 1.07468 1.08104 1.08749 1.09405 1.10072 1.10749 1.11437 1.12137 1.12848 1.13571 1.14306 1.15055 1.15816
1.00000 1.00360 1.00725 1.01095 1.01469 1.01849 1.02233 1.02622 1.03016 1.03416 1.03822 1.04232 1.04649 1.05071 1.05500 1.05934 1.06375 1.06823 1.07277 1.07738 1.08206 1.08681 1.09164 1.09654 1.10152 1.10659
0.74 0.73 0.72 0.73 0.70 0.69 0.68 0.67 0.66 0.65 0.64 0.63 0.62 0.61 0.60 0.59 0.58 0.57 0.56 0.55 0.54 0.53 0.52 0.51 0.50 0.49
f(T) 1.25097 1.26315 1.27558 1.28825 1.30119 1.31439 1.32786 1.34162 1.35567 1.37002 1.38469 1.39968 1.41500 1.43068 1.44672 1.46313 1.47993 1.49713 1.51475 1.53281 1.55133 1.57031 1.58979 1.60978 1.63030 1.65139
33.18° 38.15°
36.37° 38.15°
54.28° 38.15°
f(T)
f(T)
f(T)
1.18219 1.19089 1.19975 1.20877 1.21797 1.22734 1.23689 1.24663 1.25657 1.26670 1.27705 1.28761 1.29839 1.30941 1.32066 1.33216 1.34392 1.35595 1.36825 1.38084 1.39374 1.40695 1.42048 1.43435 1.44858 1.46318
1.16591 1.17379 1.18182 1.19000 1.19832 1.20681 1.21546 1.22427 1.23326 1.24242 1.25177 1.26131 1.27105 1.28100 1.29116 1.30153 1.31214 1.32298 1.33408 1.34542 1.35704 1.36893 1.38111 1.39359 1.40639 1.41952
1.11173 1.11696 1.12228 1.12769 1.13320 1.13880 1.14450 1.15030 1 15621 1.16223 1.16837 1.17462 1.18099 1.18749 1.19411 1.20088 1.20778 1.21483 1.22203 1.22939 1.23691 1.24460 1.25246 1.26051 1.26875 1.27719
T = Sample transmittance (see step 15) f(T) = Sample correction factor (see step 15)
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ​VANADIUM OXIDES: METHOD 7504, Issue 2, dated 15 August 1994 - Page 10 of 10 Table 4.
Matrix absorption correction factors for ammonium metavanadate/silver peaks by degrees two-theta.
NH 4VO 3 Silver
15.07° 38.15°
18.10° 21.46° 23.60 38.15° 38.15° 38.15°
15.07° 18.10° 21.46° 23.60° 38.15° 38.15° 38.15° 38.15°
T
f(T)
f(T)
f(T)
f(T)
T
f(T)
f(T)
f(T)
f(T)
1.00 0.99 0.98 0.97 0.96 0.95 0.94 0.93 0.92 0.91 0.90 0.89 0.88 0.87 0.86 0.85 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75
1.0000 1.0126 1.0254 1.0384 1.0517 1.0653 1.0791 1.0932 1.1075 1.1221 1.1371 1.1523 1.1678 1.1836 1.1997 1.2162 1.2330 1.2501 1.2676 1.2855 1.3038 1.3224 1.3414 1.3609 1.3807 1.4474
1.0000 1.0105 1.0211 1.032 1.043 1.0542 1.0656 1.0773 1.0891 1.1011 1.1134 1.1259 1.1386 1.1516 1.1648 1.1783 1.1920 1.2060 1.2202 1.2348 1.2496 1.2647 1.2801 1.2959 1.3120 1.3284
1.0000 1.0088 1.0178 1.0270 1.0362 1.0457 1.0553 1.0650 1.0749 1.0850 1.0953 1.1057 1.1164 1.1272 1.1382 1.1494 1.1608 1.1724 1.1842 1.1963 1.2086 1.2211 1.2338 1.2468 1.2601 1.2736
1.0000 1.0081 1.0162 1.0245 1.0330 1.0415 1.0503 1.0591 1.0681 1.0773 1.0866 1.0960 1.1056 1.1154 1.1254 1.1355 1.1458 1.1563 1.1669 1.1778 1.1889 1.2002 1.2116 1.2233 1.2353 1.2474
0.74 0.73 0.72 0.71 0.70 0.69 0.68 0.67 0.66 0.65 0.64 0.63 0.62 0.61 0.60 0.59 0.58 0.57 0.56 0.55 0.54 0.53 0.52 0.51 0.50 0.49
1.0000 1.0126 1.0254 1.0384 1.0517 1.0653 1.0791 1.0932 1.1075 1.1221 1.1371 1.1523 1.1678 1.1836 1.1997 1.2162 1.2330 1.2501 1.2676 1.2855 1.3038 1.3224 1.3414 1.3609 1.3807 1.4010
1.0000 1.0105 1.0211 1.0320 1.0430 1.0542 1.0656 1.0773 1.0891 1.1011 1.1134 1.1259 1.1386 1.1516 1.1648 1.1783 1.1920 1.2060 1.2202 1.2348 1.2496 1.2647 1.2801 1.2959 1.3120 1.3284
1.0000 1.0088 1.0178 1.0270 1.0362 1.0457 1.0553 1.0650 1.0749 1.0850 1.0953 1.1057 1.1164 1.1272 1.1382 1.1494 1.1608 1.1724 1.1842 1.1963 1.2086 1.2211 1.2338 1.2468 1.2601 1.2736
1.0000 1.0081 1.0162 1.0245 1.0330 1.0415 1.0503 1.0591 1.0681 1.0773 1.0866 1.0960 1.1056 1.1154 1.1254 1.1355 1.1458 1.1563 1.1669 1.1778 1.1889 1.2002 1.2116 1.2233 1.2353 1.2474
T = Sample transmittance (see step 15) f(T) = Sample correction factor (see step 15)
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94