ETHYL ACETATE

1457

CH3COOC2H5 MW: 88.10 CAS: 141-78-6 RTECS: AH5425000

METHOD: 1457, Issue 1 EVALUATION: FULL Issue 1: 15 August 1994

OSHA : 400 ppm PROPERTIES: liquid, d = 0.8945 g/mL @ 25 °C;

NIOSH: 400 ppm BP = 77 °C; VP = 9.7 kPa (73 mm Hg)
ACGIH: 400 ppm @ 20 °C
(1 ppm = 360 mg/m 3 @ NTP)

SYNONYMS: acetic ether; acetic ester; ethyl ethanoate

SAMPLING MEASUREMENT

SAMPLER: SOLID SORBENT TUBE TECHNIQUE: GAS CHROMATOGRAPHY, FID

(coconut shell charcoal, 100 mg/50 mg)
ANALYTE: ethyl acetate
FLOW RATE: 0.01 to 0.2 L/minute
EXTRACTION: 1 mL CS 2
VOL-MIN: 0.1 L @ 1400 mg/m 3
-MAX: 10 L INJECTION VOLUME: 1 µL

SHIPMENT: refrigerated TEMPERATURE-INJECTION: 250 °C

-DETECTOR: 300 °C
SAMPLE -COLUMN: 35 °C, 2 min;
STABILITY: 6 days @ 5 °C [1] 10 °C/min to 150 °C

BLANKS: 2 to 10 field blanks per set COLUMN: DB-Wax; 30 m, 0.32-mm ID, 1-µm film
thickness

CARRIER GAS: He, 1 mL/min

ACCURACY MAKEUP GAS: N 2, 30 mL/min

CALIBRATION: standard solutions of ethyl acetate in CS 2

RANGE STUDIED: 704 to 2950 mg/m 3 [2]
(6-L samples) RANGE: 1.5 to 1,000 µg per sample [1]
BIAS: -2.1%
ESTIMATED LOD: 0.5 µg per sample [1]
OVERALL PRECISION (ŜrT): 0.058 [2]
PRECISION (Sr): 0.019 @ 40.5 to 810 µg per sample [1]
ACCURACY: ±11.8%

APPLICABILITY: The working range is 0.07 to 790 ppm (0.25 to 2800 mg/m 3) for a 6-L air sample [2]. The method may be
adapted for other esters with appropriate changes in chromatographic conditions.

INTERFERENCES: Any compounds with similar retention times.

OTHER METHODS: This revises Method S49 [2]. Improved recovery of analyte may be achieved with the addition of 5% butyl
carbitol to the CS 2 desorption procedure [3,4].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

 ETHYL ACETATE: METHOD 1457, Issue 2, dated 15 August 1994 - Page 2 of 4

REAGENTS: EQUIPMENT:

1. Carbon disulfide,* chrom. grade. 1. Sampler: glass tube, 7 cm long, 6-mm OD, 4-
2. Ethyl acetate, reagent grade. mm ID, flame-sealed ends with plastic caps,
3. Helium, purified. containing two sections of activated (600 °C)
4. Hydrogen, prepurified. coconut shell charcoal (front = 100 mg; back
5. Air, filtered, compressed. = 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
* See SPECIAL PRECAUTIONS. 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. Refrigerant, bagged ("Blue Ice," or equivalent).
4. Gas chromatograph, FID, integrator and
column (page 1457-1).
5. Vials, glass, 2-mL, PTFE-lined caps.
6. Syringes, 10-µL and other convenient sizes for
preparing standards, readable to 0.1 µL.
7. Volumetric flasks, 10-mL.

SPECIAL PRECAUTIONS: Carbon disulfide is toxic and an acute fire and explosion hazard (flash point
= -30 °C.) Use only in a hood.

SAMPLING:

1. Calibrate each personal sampling pump with a representative sampler in line.

2. Break the ends of the sampler immediately before sampling. Attach sampler to personal
sampling pump with flexible tubing.
3. Sample at an accurately known flow rate between 0.01 and 0.2 L/min for a total sample size of
0.2 to 10 L.
4. Cap the samplers with plastic (not rubber) caps and pack securely for shipment with bagged
refrigerant.

SAMPLE PREPARATION:

5. Place the front and back sorbent sections of the sampler tube in separate vials. Discard the
glass wool and foam plugs.
6. Add 1.0 mL CS 2 to each vial. Attach crimp cap to each vial.
NOTE: Decane or other suitable internal standard at 0.1% v/v may be added at this step.
7. Allow to stand 30 min with occasional agitation.

CALIBRATION AND QUALITY CONTROL:

8. Calibrate daily with at least six working standards over the range 8 to 1000 µg analyte per
sample.
a. Add known amounts of analyte to CS 2 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 (peak area of analyte vs. mg ethyl acetate).

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

 ETHYL ACETATE: METHOD 1457, Issue 2, dated 15 August 1994 - Page 3 of 4

9. Determine desorption efficiency (DE) at least once for each lot of charcoal used for sampling in
the calibration range (step 8). Prepare three tubes at each of five concentrations plus three
media blanks.
10. Determine desorption efficiency (DE) for each lot of charcoal tubes used for sampling in the
calibration range (step 9).
a. Remove and discard back sorbent section of a media blank sampler.
b. Inject a known amount of calibration 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. µg ethyl acetate recovered.
11. Analyze three quality control blind spikes and three analyst spikes to insure that the calibration
graph and DE graph are in control.

MEASUREMENT:

12. Set gas chromatograph according to manufacturer's recommendations and to conditions given
on page 1457-1. 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 CS 2,
reanalyze, and apply the appropriate dilution factor in calculations.
13. Measure peak area.

CALCULATIONS:

14. Determine the mass, µg (corrected for DE), of ethyl acetate 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.
15. Calculate concentration, C, of ethyl acetate in the air volume sampled, V (L), at the sampling
site:

EVALUATION OF METHOD:

Method S49 [2] was evaluated over the range of 704 to 2950 mg/m 3 for 6-L samples at 23 °C and a
pressure of 759 mm Hg. The overall sampling and analytical precision ( ŜrT) was 0.058 with an average
recovery of 97.9% and the breakthrough capacity was found to be 25 mg of ethyl acetate [5]. The
method was updated later for a lower range (40.5 to 810 µg/sample) with a capillary column [1].
Desorption efficiencies ranged from 44.5% to 87.5% with an analytical precision ( Sr) of 0.058. Samples
of ethyl acetate on coconut charcoal are stable for 6 days at 5 °C with a recovery of 91.0% based on
samples analyzed immediately after collection [1].

REFERENCES:

[1] S.M. Pendergrass, Ethyl Acetate Method Development (unpublished report), NIOSH/MRSB,
1990, NIOSH Seq. Report 7716-F (unpublished, Feb. 5, 1993).
[2] NIOSH Manual of Analytical Methods, 2nd ed., V. 2, S49, U.S. Dept. of Health, Education, and
Welfare, Publ. (NIOSH) 77-157B (1977).

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

 ETHYL ACETATE: METHOD 1457, Issue 2, dated 15 August 1994 - Page 4 of 4

[3] Analysis of NIOSH Samples for Ethyl Acetate, NIOSH/MRSB/MDS, Sequence #7133 -
Cincinnati, Ohio (unpublished, 1991).
[4] Beck, S., T. Stock, and L. Whitehead, Improved Efficiency of Desorption of Oxygenated
Solvents from Activated Charcoal Using a New Polar Additive to Carbon Disulfide, Appl. Occup.
Environ . Hyg., 5(3), 171-177, 1990.
[5] Documentation of the NIOSH Validation Tests, U.S. Department of Health, Education, and
Welfare, Publ. (NIOSH) 77-185(1977).

METHOD REVISED BY:

S.M. Pendergrass, NIOSH/DPSE.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94