Page:NIOSH Manual of Analytical Methods - 5040.pdf/1

 DIESEL PARTICULATE MATTER (as Elemental Carbon) C

AW: 12.01

METHOD: 5040: Issue 3

CAS: none

RTECS: none

EVALUATION: FULL

OSHA : no PEL NIOSH: no REL ACGIH: 20 :g/m as elemental carbon (proposed [1])

PROPERTIES:

5040

Issue 1: 15 May 1996 Issue 3: 15 March 2003 Issue :10 March 2016 nonvolatile solid

3

SYNONYMS (related terms): diesel particulate matter, diesel exhaust, diesel soot, diesel emissions

SAMPLING

MEASUREMENT

SAMPLER:

FILTER: quartz-fiber, 37-mm; sizeselective sampler may be required [2].

TECHNIQUE:

Thermal-optical analysis; flame ionization detector (FID)

FLOW RATE:

2 to 4 L/min (typical)

ANALYTE:

VOL-MIN: -MAX:

142 L @ 40 :g/m3 19 m3 (for filter load of ~ 90 :g/cm2 )

Elemental carbon (EC). Total carbon is determined, but an EC exposure marker was proposed. See [2] for details.

SHIPMENT:

Routine

FILTER PUNCH SIZE:

1.5 cm2 (or other [2])

SAMPLE STABILITY:

Stable

CALIBRATION:

Methane injection

BLANKS:

2 to 10 field blanks per set

RANGE:

1 to 105 :g per filter portion (See also [2].)

ACCURACY RANGE STUDIED:

23 to 240 :g/m3 (See also ref. [2].)

BIAS:

None (See also ref. [2].)

OVERALL PRECISION ( Ö r T ):

0.085 at 23 :g/m3 (See also ref. [2].)

ACCURACY:

± 16.7% at 23 :g/m3 (See also ref. [2].)

ESTIMATED LOD: 0.3 :g per filter portion PRECISION ( þ r ):

0.19 @ 1 :g C, 0.01 @ 10 to 72 :g C

APPLICABILITY: The working range is approximately 6 to 630 :g/m3, with an LOD of ~ 2 :g/m3 for a 960-L air sample collected on a 37-mm filter with a 1.5 cm2 punch from the sample filter. If a lower LOD is desired, a larger sample volume and/or 25-mm filter may be used (e.g., a 1920-L sample on 25-mm filter gives an LOD of 0.4 :g/m3 ). The split between organic carbon (OC) and EC may be inaccurate if the sample transmittance is too low. The EC loading at which this occurs depends on laser intensity. In general, the OC-EC split may be inaccurate when EC loadings are above 20 :g/cm2. High loadings can give low (and variable) EC results because the transmittance remains low and relatively constant until some of the EC is oxidized. The split should be reassigned (prior to EC peak) in such cases [3]. An upper EC limit of 800 :g/m3 (90 :g/cm2 ) can be determined.

INTERFERENCES: Total carbon (as OC and EC) is determined by the method, but EC was recommended as a measure of workplace exposure because OC interferences may be present [2, 3]. Cigarette smoke and carbonates ordinarily do not interfere in the EC determination. Less than 1% of the carbon in cigarette smoke is elemental. If heavy loadings of carbonate are anticipated, a size-selective sampler (impactor and/or cyclone) should be used [2]. For measurement of diesel-source EC in coal mines, a cyclone and impactor with a submicrometer cutpoint are required to minimize collection of coal dust. A cyclone and/or impactor may be necessary in other workplaces if EC-containing dusts are present.

OTHER METHODS: Other methods for determination of EC and OC have been employed, but these are not equivalent to the method described herein. Information on other methods is summarized elsewhere [2].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition