Page:NIOSH Manual of Analytical Methods - 1615.pdf/1

 METHYL tert-BUTYL ETHER

CH3OC(CH3)3

MW: 88.15

METHOD: 1615, Issue 2

CAS: 1634-04-4

1615

RTECS: KN5250000

EVALUATION: PARTIAL

OSHA : No permissible exposure limit NIOSH: No recommended exposure limit ACGIH: No threshold limit value (1 ppm = 3.6 mg/m 3 @ NTP)

PROPERTIES:

Issue 1: 15 August 1990 Issue 2: 15 August 1994

liquid; d 0.74 g/mL @ 20 °C; BP 55.2 °C; VP 32.6 kPa (245 mm Hg) @ 25 °C

SYNONYMS: MTBE; 2-methoxy-2-methyl-propane.

SAMPLING SAMPLER:

TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

methyl tert-butyl ether (MTBE)

FLOW RATE: 0.1 to 0.2 L/min

DESORPTION:

2 mL CS 2, 30 min

VOL-MIN: -MAX:

2 L @ 10 ppm 96 L

INJECTION VOLUME:

1 µL, split ratio 60:1

SHIPMENT:

routine

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

SAMPLE STABILITY:

BLANKS:

SOLID SORBENT TUBES (two charcoal tubes in series; front 400 mg; back 200 mg)

MEASUREMENT

at least 5 days @ 25 °C, 3 weeks @ -7 °C (92% recovery) [1]

200 °C 250 °C 0 °C for 7 min; 5 °C/min to 25 °C, and then 25 °C/min to 250 °C (hold 5 min)

2 to 10 field blanks per set CARRIER GAS:

He, 1 to 2 mL/min

COLUMN:

fused silica capillary, 50 m x 0.3-mm ID, 0.5-µm film of bonded dimethylsilicone gum (polydimethylsiloxane)

CALIBRATION:

standard solutions of MTBE in CS 2

RANGE:

0.06 to >10 mg per sample [1]

ACCURACY RANGE STUDIED:

not studied

BIAS:

not significant [1]

ˆ ): not determined OVERALL PRECISION (S rT ACCURACY:

not determined

ESTIMATED LOD: 0.02 mg per sample [1] PRECISION (Sr):

0.033 @ 9 µg to

10 mg per sample [1]

APPLICABILITY: The working range is 0.2 to >35 ppm (0.75 to >125 mg/m 3) for an 80-L air sample. This method is designed for the determination of MTBE in gasoline and may be used for the determination of other components of gasoline.

INTERFERENCES: 2,3-Dimethylbutane may interfere if initial chromatographic temperatures are higher than 0 °C.

OTHER METHODS: This is a new method [1].

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