ALCOHOLS II
Table 1
MW: Table 1
METHOD: 1401, Issue 2
CAS: Table 2
Issue 1: 15 February 1984 Issue 2: 15 August 1994
PROPERTIES: Table 1
(1) (2) (3) (4)
n-butyl alcohol: 1-butanol; n-Butanol; Propyl carbinol sec-butyl alcohol: 2-butanol; methyl ethyl carbinol; 2-hydroxybutane. isobutyl alcohol: 2-methyl-1-propanol; isopropyl carbinol; IBA. n-propyl alcohol: 1-propanol; ethyl carbinol.
SAMPLING SAMPLER:
RTECS: Table 2
EVALUATION: FULL
OSHA : Table 2 NIOSH: Table 2 ACGIH: Table 2 COMPOUNDS and SYNONYMS:
1401
MEASUREMENT
SOLID SORBENT TUBE (coconut shell charcoal, 100 mg/50 mg)
TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
compounds above
DESORPTION:
1 mL 1% 2-propanol in CS2
INJECTION VOLUME:
5 µL
FLOW RATE: 0.01 to 0.2 L/min
VOL-MIN: -MAX:
(1) 2L 10 L
(2) 2L 10 L
(3) 2L 10 L
SHIPMENT:
routine
SAMPLE STABILITY:
unknown; store in freezer
BLANKS:
2 to 10 field blanks per set
(4) 1L 10 L
TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:
200 °C 250-300 °C 75 °C
CARRIER GAS:
N2 or He, 20 mL/min
COLUMN:
glass, 3 m x 2-mm ID, 10% SP-1000 on 80/100 mesh Chromosorb WHP, or equivalent
CALIBRATION:
solutions of analyte in eluent (internal standard optional)
ACCURACY RANGE STUDIED:
see EVALUATION OF METHOD
BIAS:
not significant [1]
ˆ ): OVERALL PRECISION (S rT METHOD ACCURACY:
± 15%
see EVALUATION OF
RANGE AND PRECISION:
see EVALUATION OF METHOD
ESTIMATED LOD: 0.01 mg per sample [2]
APPLICABILITY: This method may be used to determine two or more analytes simultaneously by varying GC conditions (e.g., temperature programming).
INTERFERENCES: The methods were validated using a 3 m x 3-mm ID stainless steel column packed with 10% FFAP on Chromosorb W-AW; other columns with equal or better resolution (e.g., capillary) may be used.
OTHER METHODS: This method combines and replaces Methods S66, S53, S64 and S62 [3].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ALCOHOLS II: METHOD 1401, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS:
EQUIPMENT:
1. Eluent: Carbon disulfide* (chromatographic grade) with 1% (v/v) 2-propanol and 0.2% (v/v) n-undecane, 0.1% (v/v) hexane or other suitable standard. 2. Analyte. 3. DE stock solution, 100 mg/mL. Prepare solutions of each analyte in heptane. 4. Nitrogen, purified. 5. Hydrogen, prepurified. 6. Air, compressed, filtered.
See SPECIAL PRECAUTIONS.
1. Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID, flame-sealed ends, containing two sections of activated (600 °C) coconut shell charcoal (front = 100 mg; back - 50 mg) separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. 2. Personal sampling pump, 0.01 to 0.2 L/min, with flexible connecting tubing. 3. Gas chromatograph, FID, integrator and column (page 1401-1). 4. Vials, glass, 2-mL, PTFE-lined crimp caps. 5. Syringe, 10-µL, readable to 0.1 µL. 6. Volumetric flasks, 10-mL.
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and an acute fire and explosion hazard (flash point = -30 °C); all work with it must be done in a hood.
SAMPLING: 1. 2. 3. 4.
Calibrate each personal sampling pump with a representative sampler in line. Break the ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.2 L/min for a total sample size of 1 to 10 L (2 to 10 L for sec-butanol and isobutyl alcohol). Cap the samplers with plastic (not rubber) caps and pack securely for shipment.
SAMPLE PREPARATION: 5. 6. 7.
Place the front and back sorbent sections of the sampler tube in separate vials. Discard the glass wool and foam plugs. Add 1.0 mL eluent to each vial. Attach crimp cap to each vial. Allow to stand 30 min with occasional agitation.
CALIBRATION AND QUALITY CONTROL: 8.
9.
Calibrate daily with at least six working standards covering the range of the samples. a. Add known amounts of analyte to eluent in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samples and blanks (steps 11 and 12). c. Prepare calibration graph (ratio of peak area of analyte to peak area of internal standard vs. mg analyte). Determine desorption efficiency (DE) at least once for each batch of charcoal used for sampling in the calibration range (step 8). Prepare three tubes at each of five levels plus three media blanks. a. Remove and discard back sorbent section of a media blank sampler. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ALCOHOLS II: METHOD 1401, Issue 2, dated 15 August 1994 - Page 3 of 4
10.
b. Inject a known amount of DE stock solution directly onto front sorbent section with a microliter syringe. c. Cap the tube. Allow to stand overnight. d. Desorb (steps 5 through 7) and analyze together with working standards (steps 11 and 12). e. Prepare a graph of DE vs. mg analyte recovered. Analyze three quality control blind spikes and three analyst spikes to insure that the calibration graph and DE graph are in control.
MEASUREMENT: 11.
12.
Set gas chromatograph according to manufacturer's recommendations and to conditions given on page 1401-1. Inject sample aliquot manually using solvent flush technique or with autosampler. NOTE: If peak area is above the linear range of the working standards, dilute with eluent, reanalyze and apply the appropriate dilution factor in calculations. Measure peak area. Divide the peak area of analyte by the peak area of internal standard on the same chromatogram.
CALCULATIONS: 13.
14.
Determine the mass, mg (corrected for DE) of analyte found in the sample front (W f) and back (Wb) sorbent sections, and in the average media blank front (B f) and back (Bb) sorbent sections. NOTE: If Wb > Wf/10, report breakthrough and possible sample loss. Calculate concentration, C, of analyte in the air volume sampled, V (L):
EVALUATION OF METHOD: Methods S66 (n-butyl alcohol), S53 (sec-butyl alcohol), S64 (isobutyl alcohol), and S62 (n-propyl alcohol) were issued on January 17, 1975, and validated using 10-L air samples of atmospheres generated by injection of the pure alcohol into dry air using a calibrated syringe drive [1]. No stability studies were done. Overall precision and recovery were as shown below, representing non-significant bias in each method:
Method S66 S53 S64 S62
Overall Precision ˆ rT) (S
Recovery (%)
0.065 0.066 0.073 0.075
100.0 107.2 100.0 103.5
Range Studied mg/m3 mg per sample 170 270 180 225
to to to to
610 850 620 835
1.5 2.2 1.5 2.5
to to to to
6 9 6 10
Breakthrough @ 2X OSHA Avg. in Dry Air DE 35 15 31 19
L L L L
0.89 0.92 0.85 0.89
Measurement Precision (Sr) 0.021 0.028 0.023 0.016
REFERENCES: [1] [2]
Documentation of the NIOSH Validation Tests, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). User check, UBTL, NIOSH Sequence #3990-X (unpublished, November 3, 1983). NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 ALCOHOLS II: METHOD 1401, Issue 2, dated 15 August 1994 - Page 4 of 4 [3]
NIOSH Manual of Analytical Methods, 2nd ed., V. 2., U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977).
METHOD REVISED BY: George Williamson, NIOSH/DPSE; S53, S62, S64 and S66 originally validated under NIOSH Contract 99-74-45.
TABLE 1. PROPERTIES
Compound
Formula
mg/m3 = 1 ppm @ NTP
M.W.
Density (g/mL)
BP (°C)
VP @ 20 °C, kPa (mm Hg)
n-Butyl alcohol
CH3CH2CH2CH2OH; C4H10O
3.03
74.12
0.810 @ 20°C
117
0.56 (4.2)
sec-Butyl alcohol
CH3CH(OH)CH2CH3; C4H10O
3.03
74.12
0.808 @ 20°C
99.5
1.7 (13)
Isobutyl alcohol
(CH3)2CHCH2OH; C4H10O
3.03
74.12
0.806 @ 15°C
n-Propyl alcohol
CH3CH2CH2OH; C 3H 8O
2.46
60.09
0.805 @ 20°C
108 1.2 (9) 97 2.0 (15)
TABLE 2. GENERAL INFORMATION Exposure Limits (ppm) COMPOUND
CAS#
RTECS#
OSHA
NIOSH
ACGIH
n-Butyl alcohol
71-36-3
EO1400000
100 TWA
C 50 (skin)
C 50 (skin)
sec-Butyl alcohol
78-92-2
EO1750000
150 TWA
100 TWA; 150 STEL
100 TWA
Isobutyl alcohol
78-83-1
NP9625000
100 TWA
50 TWA
50 TWA
n-Propyl alcohol
71-23-8
UH8225000
200 TWA
200 TWA; 250 STEL (skin)
200 TWA; 250 STEL (skin)
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94