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
