Significance and Use
The health of workers in many industries is at risk through exposure by inhalation to toxic metals. Industrial hygienists and other public health professionals need to determine the effectiveness of measures taken to control workers' exposures, and this is generally achieved by making workplace air measurements. Exposure to some metal-containing particles has been demonstrated to cause dermatitis, skin ulcers, eye problems, chemical pneumonitis, and other physical disorders (1).
AAS is capable of quantitatively determining most metals in air samples at the levels required by federal, state, and local occupational health and air pollution regulations. The analysis results can be used for the assessment of workplace exposures to metals in workplace air.
1.1 This practice covers the collection, dissolution, and determination of trace metals in workplace atmospheres, by flame atomic absorption spectrophotometry.
1.2 The sensitivity, detection limit, and optimum working concentration for 23 metals are given in Table 1.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (Specific safety precautionary statements are given in Section 9.)
TABLE 1 AAS Instrumental Detection Limits and Optimum Working Concentration for 23 Metals
|Element||Detection Limit, μg/mL |
(approximately three times
standard deviation of blank)A
|Optimum Linear Range|
|TLV, mg/m3 (elements, compound classes, and oxides)B|
|Ag||0.001||5||0.1 (metal) 0.01 (soluble compounds as Ag)|
|Al||0.04||50||2.0 (soluble salts and alkyls not otherwise classified) 10 (metal dust and oxide)|
|5 (pyro powder and welding fume)|
|Ba||0.01||10||0.5 (soluble compounds)|
|Bi||0.03||10||No Limit expressed for this element|
|Ca||0.002||1||2 (oxide as CaO)|
|Cd||0.0008||1||0.01 (elemental and compounds|
|0.002 (elemental compounds|
|Co||0.009||5||0.02 (elemental and inorganic) 0.1 (carbonyl and hydrocarbonyl)|
|Cr||0.003||5||0.5 (metal and Cr III compounds) 0.05 (water soluble Cr VI compounds)|
|0.01 (insoluble Cr VI compounds)|
|Cu||0.002||5||0.2 (fume) 1 (dust and mists as Cu)|
|Fe||0.005||5||5 (iron oxide fume) 5 (soluble salts as Fe)|
|In||0.03||50||0.1 (metal and compounds)|
|K||0.003||1||No Limit expressed for this element|
|Li||0.0008||1||No Limit expressed for this element|
|Mg||0.0002||0.5||10 (as MgO fume)|
|Mn||0.002||5||0.2 (elemental and inorganic compounds)|
|Na||0.0003||0.5||No Limit expressed for this element|
|Ni||0.006||5||0.05 (elemental, soluble and insoluble compounds)|
|Pb||0.02||10||0.15 (inorganic compounds, fume, dust)|
|Rb||0.003||5||No Limit expressed for this element|
|Sr||0.003||5||No Limit expressed for this element|
|Tl||0.02||50||0.1 (soluble compounds)|
|V||0.06||100||0.05 (pentoxide, respirable dust or fume, as V2O5)|
|Zn||0.002||1||10 (oxide dust as ZnO) 5 (oxide fume as ZnO)|
A These detection limits represent ideal laboratory conditions; variability due to sampling, digestion, reagents, and sample handling has not been taken into account.
B Threshold Limit Values of Airborne Contaminants and Physical Agents adopted by ACGIH for 1994–1995. Values are elemental concentrations except as noted.