Page:NIOSH Manual of Analytical Methods - 2018.pdf/1

 ALIPHATIC ALDEHYDES FORMULA: Table 1

MW: Table 1

METHOD: 2018

2018

CAS: Table 1

EVALUATION: PARTIAL

OSHA : Table 2 NIOSH: Table 2 ACGIH: Table 2

RTECS: Table 1 Issue 1: 15 March 2003

PROPERTIES: Table 1

COMPOUNDS AND SYNONYMS: See Table 3

SAMPLING SAMPLER:

CARTRIDGE (containing silica gel coated with acidified 2,4dinitrophenylhydrazine)

FLOW RATE:

0.1 to 1.5 L/min

VOL-MIN: -MAX:

1 L @ 0.68 to 1.3 mg/m3 15 L @ 7.0 to 15 mg/m3

SHIPMENT:

Ship cold (0 to 5 o C).

SAMPLE STABILITY: BLANKS:

MEASUREMENT TECHNIQUE:

HPLC; UV DETECTION

ANALYTE:

2,4-dinitrophenylhydrazones of aldehydes (Table 1)

EXTRACTION:

Elution with 10 mL of carbonyl-free acetonitrile

INJECTION VOLUME:

20 µL

MOBILE PHASE:

Acetonitrile:water (see Table 1 for percentages); 1.3 mL/min

COLUMN:

Stainless steel, 3.9 x 150 mm, packed with 5-µm C-18, Symmetry™ or equivalent

DETECTOR:

UV @ 360 nm

CALIBRATION:

Standard solutions of aldehydeDNPH derivatives in acetonitrile

RANGE:

See Table 4 [1]

ESTIMATED LOD:

See Table 4

PRECISION ( þ r ):

See Table 5 [1]

>30 days @ 5 o C [1] 2 to 10 field blanks per set 6 to 10 media blanks per set

ACCURACY RANGE STUDIED:

Not studied

BIAS:

Not determined

OVERALL PRECISION ( Ö rT ):

Not determined

ACCURACY:

Not determined

APPLICABILITY: Working ranges are approximately 0.05 to 15 mg/m3 (approximately 0.02 to 4 ppm) for 15-L air samples for the four aldehydes. This method can be used for the determination of acetaldehyde and valeraldehyde for OSHA STEL and PEL exposures. Upper limits of the method for the Supelco sampler are 105, 183, 50, and 50 µg per sample for acetaldehyde, propionaldehyde, valeraldehyde, and isovaleraldehyde, respectively. INTERFERENCES: Ozone has been observed to consume the 2,4-dinitrophenylhydrazine (2,4-DNPH) reagent and to degrade the DNPH derivative of formaldehyde [2]. Thus, ozone may degrade other aldehyde-DNPH derivatives. An ozone scrubber may be attached to the inlet of the sampler to remove ozone from the air; this scrubber may contain granular potassium iodide to reduce ozone to oxygen. Ketones and other aldehydes can react with 2,4-DNPH; the derivatives produced, however, generally are separated chromatographically from the analyte of interest. OTHER METHODS: ASTM method D5197-97 and EPA compendium method TO-11A are applicable to the same four aldehydes and employ air samplers containing DNPH-coated silica gel [3,4]. NIOSH methods 2538 [5] and 3507 [6] and OSHA method 68 [7] are other methods for determination of acetaldehyde in air. OSHA method 85 is applicable to valeraldehyde and employs DNPH on glass fiber filters [8].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition