Page:NIOSH Manual of Analytical Methods - 2500.pdf/1

 METHYL ETHYL KETONE CH3 COCH2 CH3

MW: 72.11

METHOD: 2500, Issue 2

CAS: 78-93-3

EVALUATION: FULL

OSHA : 200 ppm NIOSH: 200 ppm: STEL 300 ppm ACGIH: 200 ppm: STEL 300 ppm (1 ppm = 2.95 mg/m3 @ NTP)

PROPERTIES:

2500

RTECS: EL6475000 Issue 1: 15 February 1984 Issue 2: Rev., 15 May 1996 liquid; d 0.805 g/mL @ 20 °C; BP 79.6 °C; MP ! 86 °C; VP 13 kPa (100 mm Hg; 13% v/v) @ 25 °C; explosive range 2 to 10% v/v in air

SYNONYMS: 2-butanone; MEK

SAMPLING SAMPLER:

SOLID SORBENT TUBE (beaded carbon, ~150 mg/~75 mg)

FLOW RATE:

0.01 to 0.2 L/min

VOL-MIN: -MAX:

0.25 L @ 200 ppm 12 L

SHIPMENT:

routine

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

methyl ethyl ketone (MEK)

DESORPTION:

1 mL CS2 ; stand 30 min

INJECTION VOLUME:

5 :L

SAMPLE STABILITY:

at least 90 days @ - 5 °C [1]

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

BLANKS:

2 to 10 field blanks per set

CARRIER GAS:

N2 or He, 25 mL/min

COLUMN:

glass or stainless steel, 4 m x 2-mm ID; 20% SP-2100/0.1% Carbowax 1500 on Supelcoport 100/120

CALIBRATION:

MEK solutions in CS 2

RANGE:

0.15 to 5 mg per sample

ACCURACY RANGE STUDIED:

75 to 2250 mg/m3 [1]

BIAS:

not significant [1]

OVERALL PRECISION (Ö r T ):

0.038 [1]

ACCURACY:

± 7.4%

250 °C 300 °C 55 to 75 °C

ESTIMATED LOD: 4 :g per sample [2,3] PRECISION (þ r ):

0.04 [1]

APPLICABILITY: The working range is 17 to 560 ppm (50 to 1650 mg/m3 ) for a 3-L air sample. The method is applicable to 15-min samples. This method was developed to give improved sample stability compared to conventional charcoal tubes [3,4]. Side-by-side comparisons of this method and Method S3 were made in a sporting goods manufacturing plant in which MIBK, THF, and toluene were also present. This method has also been used successfully for methyl isobutyl ketone [1] and acetone [5].

INTERFERENCES: Under the given conditions, acetone and isopropanol have retention times similar to MEK. Mass spectrometry and other GC columns, e.g., SP-1000, or 30 m x 0.32-mm WCOT capillary coated with 1 :m DB-1, are aids to resolving interferences.

OTHER METHODS: This method is similar, except for the sampler, to Methods P&CAM 127 [6] and S3 [7,8], which it replaces.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition