Page:NIOSH Manual of Analytical Methods - 1606.pdf/1

 ACETONITRILE

CH3CN

MW: 41.06

METHOD: 1606, Issue 3

1606

CAS: 75-05-8

RTECS: AL7700000

EVALUATION: FULL

OSHA : 40 ppm NIOSH: 20 ppm ACGIH: 40 ppm; STEL 60 ppm (1 ppm = 1.68 mg/m3 @ NTP)

PROPERTIES:

Issue 1: 15 February 1984 Issue 3: 15 January 1998

liquid; d 0.783 g/mL @ 20 C; BP 82 C; VP 12 kPa ( 89 mm Hg) @ 25 C, explosive range 4.4 to 16% v/v in air

SYNONYMS: methyl cyanide, cyanomethane, ACN.

SAMPLING SAMPLER:

SOLID SORBENT TUBE (coconut shell charcoal, 400/200 mg)

FLOW RATE:

0.01 to 0.2 L/min

VOL-MIN: -MAX:

1 L @ 40 ppm 25 L

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

acetonitrile

DESORPTION:

2 mL methylene chloride/methanol (85:15); ultrasonic bath for 45 minutes.

INJECTION VOLUME:

1 µL

SHIPMENT:

keep cold; pack securely for shipment.

SAMPLE STABILITY:

at least 30 days at 5 C

TEMPERATURE-INJECTION: 250 C -DETECTOR: 300 C -COLUMN: 35 C, hold 4 min; 12 C/min to 150 C

BLANKS:

2 to 10 field blanks per set

CARRIER GAS:

He, 2.4 mL/min

COLUMN:

capillary, fused silica, 30 m x 0.32-mm ID, 1µm film, crossbonded PEG, Stabilwax® or equivalent

CALIBRATION:

solutions of acetonitrile chloride/methanol (85:15)

0.071 [1,2]

RANGE:

2.6 to 2000 µg per sample [1, 2]

± 16.4%

ESTIMATED LOD: 0.8 µg per sample [1]

ACCURACY RANGE STUDIED:

39.2 to 275 mg/m3 [1]

BIAS:

4.0%

OVERALL PRECISION ( ACCURACY:

rT

):

PRECISION ( r):

in

methylene

0.015

APPLICABILITY: The working range is 0.06 to 7.4 ppm (0.1 to 12.5 mg/m3) for a 25-L air sample [1]. Large (400 mg/200 mg) charcoal tubes are required for analyte collection, since breakthrough volume is lower with smaller charcoal tubes [2]. Analyte capacity of the large charcoal tubes has not been determined under conditions of high relative humidity [3].

INTERFERENCES: Samples containing greater than 15% methanol or other alcohols.

OTHER METHODS:This method revises NMAM 1606 (dated 8/15/94) and is based on Method S165 [4]. In this method, a capillary GC column has replaced the original packed column. Improvements include but are not limited to the following: new and less hazardous desorption solvent, smaller volume of desorption solvent required, improved desorption efficiency (DE), and lower LOD/LOQ. A storage stability study was completed and was found acceptable at 98.5% after 30 days at 5 C.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition