Page:NIOSH Manual of Analytical Methods - 3511.pdf/1

 MONOMETHYLANILINE

C6H5NH(CH3)

MW: 107.16

METHOD: 3511, Issue 1

3511

CAS: 100-61-8

RTECS: BY4550000

EVALUATION: PARTIAL

OSHA : 2 ppm (skin) NIOSH: 0.5 ppm (skin) ACGIH: 0.5 ppm (skin) (1 ppm = 4.38 mg/m 3 @ NTP)

Issue 1: 15 August 1994

PROPERTIES: liquid, discolors on standing; MP - 57 °C; BP 194 - 196 °C; d = 0.989 g/mL @ 20 °C; VP 40 Pa (0.3 mm Hg) @ 20 °C

SYNONYMS: N-methylaniline; N-methylbenzenamine

SAMPLING SAMPLER:

MIDGET BUBBLER (0.05 M sulfuric acid, 10 mL)

FLOW RATE:

0.2 to 1.0 L/min

VOL-MIN: -MAX:

11 L @ 2 ppm 100 L

SHIPMENT:

take care to prevent spillage

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

monomethylaniline

EXTRACTION:

neutralize with 1 mL 4 M NaOH

INJECTION VOLUME:

5 µL

CARRIER GAS:

N 2, 50 mL/min

SAMPLE STABILITY:

at least 7 days @ 25 °C

BLANKS:

2 to 10 field blanks per set

TEMPERATURE-INJECTOR: -DETECTOR: -COLUMN:

BULK SAMPLE:

required

COLUMN:

60/80 mesh Chromosorb 103, 2ft x 1/8"O.D., with an Ascarite precolumn

CALIBRATION:

standard solutions of monomethylaniline in sulfuric acid

RANGE:

0.1 to 3 mg per sample [1]

ACCURACY RANGE STUDIED:

4.38 to 17.52 mg/m 3 [1] (100-L samples)

BIAS:

none [1]

245 °C 275 °C 170 °C

ESTIMATED LOD: 8 µg per sample

ˆ ): 0.089 [1] OVERALL PRECISION (S rT ACCURACY:

± 26.38%

PRECISION (Sr):

0.024 [1]

APPLICABILITY: The working range is 0.2 to 7 ppm (1 to 30 mg/m 3) for a 100-L air sample. Using a nitrogen-specific detector instead of a FID will greatly increase sensitivity. This alternate detector has been used for amines with a 30-m x 0.25- mm x 0.25µm film DB-5 (5% methyl, phenyl-50% dimethyl-polysiloxane) fused-silica capillary column with a liner packed with KOH-co ated glass wool.

INTERFERENCES: None known.

OTHER METHODS: This revises Method S153 [2].

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