Page:NIOSH Manual of Analytical Methods - 3507-1.pdf/1

 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