AMMONIA
NH3
MW: 17.03
METHOD: 6015, Issue 2
CAS: 7664-41-7 EVALUATION: PARTIAL
OSHA : 50 ppm NIOSH: 25 ppm; STEL 35 ppm; Group III pesticide ACGIH: 25 ppm; STEL 35 ppm (1 ppm = 0.697 mg/m 3 @ NTP)
PROPERTIES:
6015
RTECS: BO0875000 Issue 1: 15 August 1994
gas; MP -77.7 °C; BP -33.4 °C; explosive range 16 to 25% v/v in air; vapor density 0.6 (air = 1)
SYNONYMS: none
SAMPLING SAMPLER:
SOLID SORBENT TUBE (sulfuric acid-treated silica gel) A 0.8-micron MCE prefilter may be used to remove particulate interferences.
MEASUREMENT TECHNIQUE:
VISIBLE ABSORPTION SPECTROPHOTOMETRY
ANALYTE:
indophenol blue
FLOW RATE: 0.1 to 0.2 L/min
EXTRACTION:
20 mL deionized water
VOL-MIN: -MAX:
0.1 L @ 50 ppm 96 L
COLOR DEVELOPMENT:
SHIPMENT:
routine
SAMPLE STABILITY:
not determined
BLANKS:
2 to 10 field blanks per set
EDTA antiprecipitant, phenolate coupling agent, nitroprusside intensifier, hypochlorite.
WAVELENGTH:
630 or 660 nm
CALIBRATION:
standard solutions of ammonium chloride in deionized water
RANGE:
1.5 to 20 µg per sample [1]
ACCURACY ESTIMATED LOD: 0.5 µg per sample [1] RANGE STUDIED:
not studied
ACCURACY:
not determined
BIAS:
not determined
PRECISION (Sr):
not determined
ˆ ): not determined OVERALL PRECISION (S rT
APPLICABILITY: The working range is 0.2 to 400 ppm (0.15 to 300 mg/m 3) for a 10-L air sample. This method is applicable to STEL measurements.
INTERFERENCES: None identified.
OTHER METHODS: This method is based on the sampling procedure of Method S347 [2], the automated analytical procedure of EPA Method 350.1 [3], and Standard Methods 417G [4]. NIOSH Method 6701 [5] was less sensitive, employing a passive li quid sorbent badge for collection followed by ion chromatography. NIOSH Method P&CAM 205 [6] used impinger collection and Nessler's reagent for manual colorimetric analysis. OSHA has both impinger collection with ion specific electrode analys is (ID-164) [7] and sulfuric acid-impregnated beaded carbon collection followed by ion chromatography analysis (ID-188) [8].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
