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
