Page:NIOSH Manual of Analytical Methods - 7304.pdf/1

 7304

ELEMENTS by ICP (Microwave Digestion) MW: Table 1

CAS: Table 2

RTECS: Table 2

METHOD: 7304, Issue 1

EVALUATION: FULL

Issue 1: 25 June 2014

OSHA:	 Table 2 ​ NIOSH:	Table 2 Other OELs:  [1,2]* ELEMENTS:

PROPERTIES:

Table 1

aluminum cadmium		iron		molybdenum selenium		titanium arsenic calcium		lead		nickel		sodium		vanadium barium chromium lithium phosphorus strontium yttrium beryllium cobalt		magnesium platinum		tellurium		zinc boron	copper 		manganese potassium	thallium		zirconium SAMPLING

SAMPLER:	 FILTER, (polyvinyl chloride (PVC), 37-mm diameter, 5.0 µm pore size)

MEASUREMENT TECHNIQUE:

INDUCTIVELY COUPLED ARGON PLASMA, ATOMIC EMISSION SPECTROSCOPY (ICP-AES)

ANALYTE:

Elements listed above

REAGENTS:

12 mL of 5:1 concentrated nitric acid and ASTM Type ll water

FLOW RATE:	 1 to 4 L/min VOL-MIN: -MAX:

Table 1

SHIPMENT:	 Routine

FINAL SOLUTION: 	20% HNO3, 50 mL

SAMPLE STABILITY:	 Stable BLANKS:

2 to 10 field blanks per set ACCURACY

WAVELENGTH:

Depends upon element; Table 3

BACKGROUND CORRECTION:

Spectral wavelength shift

RANGE STUDIED:

See Table 4

CALIBRATION:

Elements in 20% HNO3

ACCURACY:

See Table 4

RANGE:

See Table 4

BIAS:

See Table 4

ESTIMATED LOD:	 Table 3

OVERALL PRECISION ( SˆrT ):	 See Table 4

PRECISION ( Sr ):	 Table 3

APPLICABILITY:	 The working range of this method varies from element to element. This method is for the analysis of metal and nonmetal dust collected on PVC filters that are also used for gravimetric analysis. This is a simultaneous elemental analysis using a microwave digestion approach to simplify and expedite the analysis. Some elements such as antimony, silver, and tin do not form stable solutions in nitric acid when chloride from the PVC filters is present. In such cases a mixed cellulose ester (MCE) filter is necessary (See NMAM 7302). A different acid medium also helps but this technique is not described in this method. INTERFERENCES:	 Spectral interferences are the primary interferences encountered in ICP-AES analysis. These are minimized by judicious wavelength selection, inter-element correction factors and background correction. [3,4,5,6] OTHER METHODS:	 This method complements NIOSH hotplate digestion methods 7300 and 7301 for trace elements. Flame atomic absorption spectroscopy (e.g., Methods 7013 through 7082) is an alternative analytical technique for many of these elements. [7] Graphite furnace AAS (e.g., 7102 for Be, 7105 for Pb) is usually more sensitive. [7] NMAM 7301 and 7303 contain alternative extraction procedures.

NIOSH Manual of Analytical Methods (NMAM), Fifth Edition