Page:NIOSH Manual of Analytical Methods - 2557.pdf/1

 This method is considered historical and its use is no longer recommended. Please see the ‘Applicability’ Section for additional information. Revised: 15 August 2015.

DIACETYL

C4H6O2

MW: 86.09

METHOD: 2557, Issue 1

2557

CAS: 431-03-8

EVALUATION: PARTIAL

OSHA : no PEL NIOSH: no REL ACGIH: no TLV

RTECS: EK2625000

Issue 1: 15 March 2003

PROPERTIES:	 yellowish liquid; d = 0.981 g/mL @ 20 °C; BP 88 °C; VP 52 mm Hg @ 20 °C; FP 7 °C; flash point 21 °C

SYNONYMS: biacetyl; 2,3-butadione; 2,3-diketobutane; dimethyl diketone; dimethylglyoxal SAMPLING

MEASUREMENT

VOL-MIN: -MAX:

1L 10 L

SHIPMENT:	 Ship cold (5 °C) and store in dark SAMPLE STABILITY:	 7 days @ 5 °C 2 to 10 field blanks per set

ANALYTE:

diacetyl

DESORPTION:

1 mL of acetone/methanol (99:1) on rotary mixer for 1.5 hours

INJECTION VOLUME:

1 μL

TEMPERATURE -INJECTION: -DETECTOR: -COLUMN:

225 °C 250 °C 35 °C (hold 3 min) to 200 °C (6 C/min)

CARRIER GAS:

He (2.8 mL/min)

COLUMN:

capillary, fused silica, 30 m x 0.32-mm ID; 1-μm film, Stabilwax-DA or equivalent

CALIBRATION:

standard solutions of diacetyl in acetone/ methanol (99:1) solvent

RANGE:

2 to 470 μg/sample

ST OR

BLANKS:

GAS CHROMATOGRAPHY, FID

AL

FLOW RATE:	 0.01 to 0.2 L/min

TECHNIQUE:

IC

SAMPLER:	 SORBENT TUBE (carbon molecular sieve solid sorbent tube, 150/75 mg)

ACCURACY

RANGE STUDIED:

not determined

BIAS:

not determined

OVERALL PRECISION ( SˆrT ):

not determined

ACCURACY:

not determined

HI

ESTIMATED LOD:	 0.6 μg/sample PRECISION ( S ):	 0.018 r

APPLICABILITY:	 This method should no longer be used. Method 2557 has been found to underestimate the diacetyl concentration when sampling in air of moderate to high humidity [5.] NIOSH is evaluating an alternative method for diacetyl and other 2,3-dione compounds that involves derivitization with o-phenylenediamine. OSHA methods exist for diacetyl (OSHA 1013 and 1012) and 2,3-pentanedione (OSHA 1016.) The working range for diacetyl was 0.057 to 13.4 ppm (0.20 to 47.2 mg/m3) for a 10-L air sample. INTERFERENCES:	 Any compound with a similar retention time to diacetyl. OTHER METHODS:	 none determined

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition