Naphthas (1550)
NAPHTHAS
Table 1
MW: Table 1
METHOD: 1550, Issue 2
CAS: Table 1
1550
RTECS: Table 1
EVALUATION: FULL
OSHA : Table 1 NIOSH: Table 1 ACGIH: Table 1
Issue 1: 15 February 1984 Issue 2: 15 August 1994
PROPERTIES: Table 1
SYNONYMS: Petroleum ether (benzin), rubber solvent, petroleum naphtha, VM&P naphtha, mineral spirits, Stoddard solvent, kerosene (kerosine), coal tar naphtha. SAMPLING
MEASUREMENT
SAMPLER:
SOLID SORBENT TUBE (coconut shell charcoal, 100 mg/50 mg)
FLOW RATE:
0.01 to 0.2 L/min
VOL-MIN: -MAX:
1.3 L @ 400 mg/m 3; 0.2 L @ 2500 mg/m 3 20 L @ 400 mg/m 3; 3.2 L @ 2500 mg/m 3
SHIPMENT:
routine
TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
naphtha hydrocarbons
DESORPTION:
1 mL CS 2; stand 30 min
INJECTION VOLUME: 5 µL (packed column); 0.1 to 1 µL (capillary column)
SAMPLE STABILITY:
at least 1 week @ 25 °C
TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:
BLANKS:
2 to 10 field blanks per set
CARRIER GAS:
N 2 or He, 30 mL/min
BULK SAMPLE:
required; 5 to 10 mL
COLUMN:
glass, 3 m x 6-mm, 10% SP-2100 on Supelcoport 80/100 or 30-m fused silica capillary, 0.325-mm ID, 1.0-µm DB-1 or equivalent
ACCURACY
200 to 250 °C 250 to 300 °C 50 to 250 °C @ 8 °/min
RANGE STUDIED:
see EVALUATION OF METHOD
CALIBRATION:
solutions of bulk naphtha in CS 2
BIAS:
see EVALUATION OF METHOD
RANGE:
0.5 to 10 mg per sample [2,3,4]
ˆ ): OVERALL PRECISION (S rT ACCURACY:
0.05 [1]
see EVALUATION OF METHOD
ESTIMATED LOD: 0.1 mg per sample PRECISION (Sr):
0.01 [1]
APPLICABILITY: The working range is 100 to 2000 mg/m 3 for a 5-L air sample. This is a general procedure for analysis of various types of hydrocarbon mixtures called "naphthas" which are used as thinners in paints and varnishes and as genera l purpose solvents.
INTERFERENCES: Most naphthas are quite complex. The components elute over a wide temperature range by gas chromatography, making interferences from other substances possible. Columns and conditions must be chosen to obtain the desired degree of separation for a given mixture.
OTHER METHODS: This method combines and replaces Methods S86 [2], S380 [3] and S382 [4]. A similar method appears in the criteria document [5].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 NAPHTHAS: METHOD 1550, Issue 2, dated 15 August 1994 - Page 2 of 5 REAGENTS: 1.
2. 3. 4. 5.
EQUIPMENT:
Eluent: Carbon disulfide*, chromatographic quality, containing 0.1% (v/v) octane, 0.5% (v/v) hexadecane or other suitable internal standard. NOTE 1: Use an internal standard which is not a major constituent of the sample. NOTE 2: Use toluene in place of carbon disulfide for low-boiling analytes [5]. Naphtha bulk sample. Nitrogen or helium, purified. Hydrogen, prepurified. Air, filtered.
See SPECIAL PRECAUTIONS.
1. Sampler: glass tube, 7 cm long, 6-mm OD, 4mm 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 1550-1). 4. Vials, glass, 2-mL, PTFE-lined crimp caps. 5. Syringe, 10-µL (1-µL syringe for capillary columns) and other convenient sizes for preparing standards, readable to 0.1 µL. 6. Volumetric flasks, 10-mL. 7. Pipet, delivery, 1.0-mL, with pipet bulb.
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and an acute fire and explosion hazard (flash point = -30 °C); work with it only 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 which contains between 0.5 and 8 mg naphtha. Cap the samplers with plastic (not rubber) caps and pack securely for shipment. Ship a bulk sample (5 to 10 mL) in a separate container from the sorbent tubes.
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.
Calibrate daily with at least six working standards over the range 0.1 to 10 mg naphtha per sample. a. Add known amounts of naphtha bulk sample to eluent in 10-mL volumetric flasks and dilute to the mark. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 NAPHTHAS: METHOD 1550, Issue 2, dated 15 August 1994 - Page 3 of 5 b. c. 9.
10.
Analyze together with samples and blanks (steps 11 and 12). Prepare calibration graph (ratio of peak area of analyte to peak area of internal standard vs. mg naphtha). 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. b. Inject a known amount of naphtha bulk sample 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 naphtha 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 1550-1. Inject sample aliquot manually using solvent flush technique or with autosampler. NOTE 1: The columns and conditions given provide moderate to good separation of components. If less resolution is needed, use shorter, less efficient columns as were used in validation of Methods S86 [2], S380 [3] and S382 [4]. NOTE 2: 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 naphtha found in the sample front (W f) and back (W b) sorbent sections, and in the average media blank front (B f) and back (B b) sorbent sections. NOTE: If W b > W f/10, report breakthrough and possible sample loss. Calculate concentration, C, of naphtha in the air volume sampled, V (L):
EVALUATION OF METHOD: Methods S86 (Naphtha, Coal Tar), S380 (Petroleum distillate) and S382 (Stoddard Solvent) were issued on March 14, 1975 [2,3,4]. They were validated at 24 °C and approximately 755 mm Hg using 10-, 4and 3-L air samples, respectively, of 2-50-W Hi-Flash Solvent (Neville Chemical Co.; BP 154 to 195 °C; d 0.893 g/mL), VM&P Naphtha (Amsco Product 1101; BP 120 to 147 °C; d 0.743 g/mL) and Stoddard Solvent (Fisher Scientific Co.; BP 159 to 176 °C; d 0.774 g/mL) [1]. Overall precision and recovery were as shown below, representing a non-significant bias in each method. Breakthrough tests in dry air showed a capacity of 20 to 25 mg of each solvent tested. Capacity at high relative humidity was not determined.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 NAPHTHAS: METHOD 1550, Issue 2, dated 15 August 1994 - Page 4 of 5
Method
Overall Precision ( SˆrT)
S86 (b) S380 (a) S382 (b) NOTES:
0.051 0.052 0.052
Bias 5.99% -4.37% -3.10%
Range Studied Accuracy mg/m 3 ±15.0% ±12.5% ±11.4%
193 to 809 937 to 3930 1417 to 5940
mg per sample 2 to 8 4 to 16 4.5 to 18
Avg. DE
Ref.
0.88 0.96 0.95
[1,2] [1,3] [1,4]
(a) Data based on experiments using an internal standard method with a 10 ft., 1/8" stainless steel column packed with 10% OV-101 on 100/120 mesh Supelcoport. (b) Data based on experiments using an internal standard method with a 6 ft., 1/8" stainless steel column packed with 1.5% OV-101 on 100/120 mesh Chromosorb W.
REFERENCES: [1] [2] [3] [4] [5]
Documentation of the NIOSH Validation Tests, S86, S380, S382, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). NIOSH Manual of Analytical Methods, 2nd ed., V. 2, Method S86, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977). Ibid, V. 3, S380, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977). Ibid, S382. Criteria for a Recommended Standard...Occupational Exposure to Refined Petroleum Solvents, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-192 (July, 1977).
METHOD REVISED BY: Ardith A. Grote, NIOSH/DPSE; S86, S380 and S382 originally validated under NIOSH Contract CDC-99-74-55.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94 NAPHTHAS: METHOD 1550, Issue 2, dated 15 August 1994 - Page 5 of 5 Table 1. General information. Exposure Limits, mg/m 3 NAME OSHA CAS # Predominant RETECS Hydrocarbon Species Petroleum ether (a)
Vapor Boiling NIOSH Range (°C) ACGIH 30 to 60 C 5-C6
8032-32-4 OI6180000
Pressure, kPa (mm Hg) @ 20 °C 13 (100) -(13 °C)
Liquid Density (g/mL @ 15 °C) 0.63 to 0.66 aliphatic 350; C 1800 --
Rubber solvent (a)
45 to 125 C 5-C8
(c) 2000 (500 ppm)
SE7449000 8030-30-6
0.67 to 0.85 aliphatic 350; C 1800 1590 (400 ppm)
Petroleum naphtha (b)
30 to 238 C 6-C8
5 (40) 2000 (500 ppm)
0.6 to 0.8
(Petroleum distillates mixture) 350; C 1800 --
8002-05-9 SE7449000 VM&P naphtha (a)
95 to 160 C 7-C11
0.3 to 3 (2 to 20) --
8032-32-4 OI6180000 Mineral spirits (a)
<20% aromatic350, C 1800 1370 (300 ppm) 150 to 200 C 9-C12
0.2758(2) 2900 (500 ppm)
8052-41-3
150 to 210 C 9-C12
0.2758 (2) 2900 (500 ppm)
8052-41-3
175 to 325 C 9-C16
(c) --
8008-20-6
0.8 <20% aromatic 100 --
OA5500000 Coal tar naphtha (b)
0.75 to 0.80 <20% aromatic 350; C 1800 525 (100 ppm)
WJ8925000 Kerosene (a)
0.77 to 0.81 <20% aromatic 350; C 1800 525 (100 ppm)
WJ89250000 Stoddard solvent (a)
0.72 to 0.76
110 to 190 C 8-C10
<0.7 (<5) 400 (100 ppm)
0.86 to 0.89 NAPHTHAS: METHOD 1550, Issue 2, dated 15 August 1994 - Page 5 of 5 8030-30-6
aromatic 400 (100 ppm) --
DE3030000 (NIOSH) (a) As defined by NIOSH Criteria Document [5]. (b) As defined for OSHA PEL. (c) Not available.
NIOSH Manual of Analyatical Methods (NMAM), Fourth Edition, 8/15/94
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94