Page:NIOSH Manual of Analytical Methods - 2521.pdf/1

 METHYLCYCLOHEXANONE

CH3C6H9(=0) (3 isomers)

MW: 112.17

METHOD: 2521, Issue 2

CAS: 1331-22-2

EVALUATION:

OSHA : 100 ppm (skin) (2-methyl isomer) NIOSH: 50 ppm (skin); STEL 75 ppm (2-methyl isomer) (1 ppm = 4.59 mg/m 3 @ NTP) ACGIH: 50 ppm (skin); STEL 75 ppm (2-methyl isomer) (1 ppm = 4.59 mg/m 3 @ NTP)

2521

RTECS: GW1575000

FULL

PROPERTIES:

Issue 1: 15 May 1985 Issue 2: 15 August 1994

Isomer 2-CH 3C 6H 9O 3-CH 3C 6H 9O 4-CH 3C 6H 9O

BP, °C 165 169 170

d, g/mL @ 20 °C 0.925 0.914 0.914

SYNONYMS: Isomers: 2-methylcyclohexanone; CAS #583-60-8. 3-methylcyclohexanone; CAS #591-24-2. 4-methylcyclohexanone; CAS #589-92-4. Mixture of isomers: CAS #1331-22-2. SAMPLING SAMPLER:

SOLID SORBENT TUBE (Porapak Q, 150 mg/75 mg)

FLOW RATE:

0.01 to 0.05 L/min

VOL-MIN: -MAX:

1 L @ 460 mg/m 3 6L

SHIPMENT:

routine

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

3- and 4-methylcyclohexanone

DESORPTION:

1 mL acetone; stand 15 min

INJECTION VOLUME:

5 µL

SAMPLE STABILITY:

≥ 7 days @ 25 °C [1]

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

BLANKS:

2 to 10 field blanks per set

CARRIER GAS:

N 2, 30 mL/min

COLUMN:

stainless steel, 1.2 m x 3-mm OD, packed with 50/80 mesh Porapak Q

CALIBRATION:

standard solutions of 3- and 4- methylcyclohexanone isomers in acetone

RANGE:

0.5 to 4 mg per sample

ACCURACY RANGE STUDIED:

213 to 852 mg/m 3 [1] (3-L samples)

BIAS:

0.69%

200 °C 260 °C 190 °C

ESTIMATED LOD: 0.09 mg [1]

ˆ ): 0.057 [1] OVERALL PRECISION (S rT ACCURACY:

± 11.35%

PRECISION (Sr):

0.041 @ 0.7 to 2.9 mg per sample [1]

APPLICABILITY: The working range is 100 to 800 mg/m 3 (20 to 170 ppm) for a 5-L air sample. This method was developed for the 3- and 4-methylcyclohexanones. 2-Methylcyclohexanone is not of major commercial importance and has not been test ed with this method. The use of a capillary column would give better sensitivity; however, all the isomers may not elute as a single peak.

INTERFERENCES: None reported.

OTHER METHODS: This revises Method S375 [2].

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