Page:NIOSH Manual of Analytical Methods - 6011.pdf/2

 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