Page:NIOSH Manual of Analytical Methods - 1458.pdf/1

 METHYL ACETATE

CH3COOCH3

MW: 74.08

METHOD: 1458, Issue 2

CAS: 79-20-9

1458

RTECS: AI9100000

EVALUATION: FULL

OSHA : 200 ppm NIOSH: 200 ppm; STEL 250 ppm ACGIH: 200 ppm; STEL 250 ppm (1 ppm = 3.03 mg/m 3)

PROPERTIES:

Issue 1: 16 December 1974 Issue 2: 15 August 1994

liquid; d = 0.9244 g/mL @ 25 °C; BP = 54.05 °C; VP 23 kPa (173 mm Hg) @ 20 °C; vapor density (air = 1) 2.8

SYNONYMS: acetic acid methyl ester; methyl acetic ester; methyl ethanoate

SAMPLING SAMPLER:

MEASUREMENT

SOLID SORBENT TUBE (coconut shell charcoal, 100 mg/50 mg)

TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

methyl acetate

FLOW RATE:

0.01 to 0.2 L/minute

EXTRACTION:

1 mL CS 2

VOL-MIN: -MAX:

0.2 L @ 200 ppm 10 L

INJECTION VOLUME: 1 µL

SHIPMENT:

refrigerated

SAMPLE STABILITY:

at least 6 days @ 5 °C

BLANKS:

2 to 10 field blanks per set

ACCURACY RANGE STUDIED:

343 to 1130 mg/m 3 [1] (7-L samples)

BIAS:

7.2%

ˆ ): 0.0547 [1] OVERALL PRECISION (S rT ACCURACY:

± 16.8%

TEMPERATURE-INJECTOR: -DETECTOR: -COLUMN:

250 °C 300 °C 35 °C (2 min) to 150 °C (10 °C/min)

COLUMN:

DB-wax; 30 m, 0.32-mm ID, 1-µm film thickness

CARRIER GAS:

He, 1 mL/min;

MAKEUP GAS:

N 2, 30 mL/min

CALIBRATION:

solutions of methyl acetate in CS 2

RANGE:

7 µg to 1000 µg [2]

ESTIMATED LOD:

2 µg [2]

PRECISION (Sr):

0.036 @ 20 to 876 µg per sample [2]

APPLICABILITY: The working range is 0.3 to 1330 ppm (1 to 440 mg/m 3) for a 7-L air sample [1]. 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 S42 [1]. 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