Page:NIOSH Manual of Analytical Methods - 3507.pdf/1
Issue 2: 15 August 1994
- (1 ppm = 1.801 mg/m³ @ NTP)
SYNONYMS: ethanal; acetic aldehyde
SAMPLER: LIQUID IN BUBBLER
FLOW RATE: 0.1 to 0.5 L/min VOL-MIN: 6 L @ 200 ppm
SHIPMENT: seal bubblers to prevent leakage before
SAMPLE STABILITY: 1 week @ 25 °C in dark [1] FIELD BLANKS: 2 to 10 field blanks per set
RANGE STUDIED: 170 to 670 mg/m³ [1] (60-L samples) BIAS: 1.2% OVERALL PRECISION (ŜrT): 0.053 [1] ACCURACY: ±14.4% |
TECHNIQUE: HPLC, UV
ANALYTE: Girard T derivative SAMPLE
INJECTION COLUMN: 50 cm × 2-mm ID SS, Zipax SCX DETECTOR: UV @ 245 nm for acetaldehyde MOBILE PHASE: Na2HPO4/NaH2PO4 buffer, 0.75 mL/min CALIBRATION: standard solutions of acetaldehyde in
RANGE: 2 to 60 mg per sample [1] ESTIMATED LOD: 0.1 mg per sample [1] PRECISION (Ŝr): 0.024 @ 11 to 43 mg per sample [1] |
APPLICABILITY: The working range is 18 to 372 ppm (33 to 670 mg/m³) 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 solution [3,4].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition