Page:NIOSH Manual of Analytical Methods - 3800.pdf/1

 ORGANIC AND INORGANIC GASES BY EXTRACTIVE FTIR SPECTROMETRY

FORMULA: Table 1

MW: Table 1

METHOD: 3800, Issue 1 OSHA : NIOSH: ACGIH:

CAS: Table 1

EVALUATION: FULL

3800

RTECS: Table 1 Issue 1: 15 March 2003

PROPERTIES: Table 1

Table 1 Table 1 Table 1

SYNONYMS: See example compounds in Table 1

SAMPLING

MEASUREMENT

SAMPLER:

Portable direct-reading instrument (filter, if required)

FLOW RATE:

~0.1 to ~20 L/min (systemdependent)

TECHNIQUE:

EXTRACTIVE FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETRY

ANALYTE:

See Table 1 (Additional compounds may be identified/quantified according to data quality objectives and QA/QC requirements)

VOL-MIN: -MAX:

Instrument dependent None

PRESSURE:

Extracted gases between 725 and 795 mm Hg absolute

ANALYTICAL FREQUENCIES:

See Table 2 for example compounds

TEMPERATURE:

Extracted gases between 10 and 30 °C

CALIBRATION:

Calibration gas standards

IDENTIFICATION: BLANKS:

Nitrogen gas, or zero air

Infrared spectra interpretation and computerized reference library searches

RANGE:

See Table 2 (dependent on compound and absorption pathlength)

ESTIMATED LOD:

See Table 2 for example values at 10-meter absorption pathlength

PRECISION ( þ r ):

See Appendix E, 2B and 2C

ACCURACY RANGE STUDIED:

See Table 1

BIAS:

See Appendix E

OVERALL PRECISION ( Ö r T ):

See Appendix E

ACCURACY:

See Appendix E

APPLICABILITY: The usefulness of FTIR techniques has been demonstrated in ambient air and combustion gas mixtures [7,8]. With the participation of an experienced analyst (see Appendix A), the method can be used for the characterization of workspace air containing mixtures of volatile organic and inorganic compounds. See Table 1 for examples.

INTERFERENCES: Overlap of infrared absorption features may affect the quantification of each compound. By appropriate use of multivariable least squares analyses, the analyst may be able to obtain accurate compound concentrations for overlapping compounds.

OTHER METHODS: This method is based on portions of EPA Method 320 [1] and its addendum [2] which describe the determination of gaseous compound concentrations by extractive FTIR spectrometry. Several compatible ASTM standards describing infrared techniques and terminology are also available [3-6].

NIOSH Manual of Analytical Methods, Fourth Edition