CHLORINE
Cl2
MW: 70.91
CAS: 7782-50-5
METHOD: 6011, Issue 2
6011
RTECS: FO2100000
EVALUATION: FULL
OSHA : C 1 ppm NIOSH: 0.5 ppm; STEL 1 ppm ACGIH: 0.5 ppm; STEL 1 ppm (1 ppm = 2.90 mg/m 3 @ NTP)
PROPERTIES:
Issue 1: 15 May 1989 Issue 2: 15 August 1994
gas; d 3.214 g/L at 0 °C; BP -34.6 °C; vapor density (air = 1) 2.5
SYNONYMS: None.
SAMPLING
MEASUREMENT
SAMPLER:
PREFILTER + FILTER (PTFE, 0.5-µm + silver membrane, 25-mm, 0.45-µm)
TECHNIQUE:
ION CHROMATOGRAPHY, CONDUCTIVITY
FLOW RATE:
0.3 to 1 L/min
ANALYTE:
chloride ion (Cl -) or bromide ion (Br -)
VOL-MIN: -MAX:
2 L @ 0.5 ppm 90 L
EXTRACTION:
3 mL 6 mM Na 2S20 3, 10 min
INJECTION VOLUME:
SHIPMENT:
routine, protect from light
COLUMN:
SAMPLE STABILITY:
≥30 days at 25 °C [1]
BLANKS:
2 to 10 field blanks per set
Dionex HPIC-AG4A guard, HPIC-AS4A separator MFC-1 precolumn, AMMS anion suppressor
DETECTOR SETTING:
ACCURACY RANGE STUDIED: BIAS:
0.35 to 6.77 mg/m 3 (15-L samples) - 1.4%
50 µL
10 µS full scale
ELUENT:
0.25 mM NaHCO 3/4 mM Na 2CO 3/0.78 mM p-cyanophenol, 2 mL/min
CALIBRATION:
standard solutions of Cl - in deionized water
RANGE:
2 to 50 µg Cl - per sample [1]
ESTIMATED LOD:
0.6 µg Cl - per sample [1]
PRECISION (Sr):
0.067 @ 5.3 to 100 µg per sample [1]
ˆ ): 0.075 [1] OVERALL PRECISION (S rT ACCURACY:
± 14.8%
APPLICABILITY: The working ranges for Br 2 and Cl 2 are 0.008 to 0.4 ppm (0.06 to 2.6 mg/m 3) and 0.007 to 0.5 ppm (0.02 to 1.5 mg/m 3) respectively for a 90-L air sample. The method has sufficient sensitivity for STEL samples.
INTERFERENCES: Hydrogen sulfide gives a negative interference. HCl gives a positive interference up to a maximum of 15 µg per sample. HBr gives a positive interference as it is sampled continuously [1].
OTHER METHODS: P&CAM 209 (colorimetric) [2], OSHA Methods ID-101 [3] and ID-108 [4] are alternative methods.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
