ACETALDEHYDE
CH3CHO
MW: 44.05
METHOD: 3507, Issue 2
CAS: 75-07-0
3507
RTECS: AB1925000
EVALUATION: FULL
OSHA : 200 ppm NIOSH: carcinogen; lowest feasible level ACGIH: 100 ppm; STEL 150 ppm; suspect carcinogen (1 ppm = 1.801 mg/m 3 @ NTP)
PROPERTIES:
Issue 1: 15 August 1987 Issue 2: 15 August 1993
liquid; d 0.78 g /mL @ 20 °C; BP 20.4 °C; MP -123 °C; VP 100 kPa (750 mm Hg; 99% v/v) @ 20 °C; explosive range 4 to 60% in air
SYNONYMS: ethanal; acetic aldehyde.
SAMPLING SAMPLER:
MEASUREMENT
LIQUID IN BUBBLER (midget bubbler containing 15 mL Girard T solution @ pH 4.5)
TECHNIQUE:
HPLC, UV
ANALYTE:
Girard T derivative
FLOW RATE:
0.1 to 0.5 L/min
SAMPLE PREPARATION:
dilute 5 mL sample to 100 mL with HPLC mobile phase
VOL-MIN: -MAX:
6 L @ 200 ppm 60 L
INJECTION VOLUME:
50 µL
SHIPMENT:
seal bubblers to prevent leakage before shipping; protect from light
SAMPLE STABILITY:
1 week @ 25 °C in dark [1]
FIELD BLANKS:
2 to 10 field blanks per set
COLUMN:
50 cm x 2-mm ID SS, Zipax SCX
DETECTOR:
UV @ 245 nm for acetaldehyde
MOBILE PHASE:
HPO 24-/HPO 4- buffer, 0.75 mL/min
CALIBRATION:
standard solutions of acetaldehyde in Girard T reagent
RANGE:
2 to 60 mg per sample [1]
ACCURACY RANGE STUDIED:
170 to 670 mg/m 3 [1] (60-L samples)
BIAS:
1.2%
ˆ ): 0.053 [1] OVERALL PRECISION (S rT ACCURACY:
ESTIMATED LOD: 0.1 mg per sample [1] PRECISION (Sr):
0.024 @ 11 to 43 mg per sample [1]
± 14.4%
APPLICABILITY: The working range is 18 to 372 ppm (33 to 670 mg/m 3) for a 60-L air sample. The method is sensitive enough for short-term exposure sampling and can be used to measure lower concentrations by diluting samples to less than the recommended 100 mL.
INTERFERENCES: Other volatile aldehydes and ketones (e.g., acetone, acrolein, benzaldehyde, formaldehyde, furfural, methyl ethyl ketone, and propionaldehyde) compete for the Girard T reagent which should be kept at a two-fold molar excess over aldehyde concentration. Chromatographic conditions may be adjusted to resolve acetaldehyde from other aldehydes [1].
OTHER METHODS: This revises S345 [2]. Method 2538 is an adaptation of OSHA Method 68, which uses solid sorbent collection and GC analysis. Other reported methods for acetaldehyde use collection in 2,4-dinitrophenylhydrazine solutio n [3,4].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/93
