IODINE
I2
MW: 253.81
METHOD: 6005, Issue 2
CAS: 7553-56-2
6005
RTECS: NN1575000
EVALUATION: FULL
OSHA : C 0.1 ppm NIOSH: C 0.1 ppm; Group I Pesticide ACGIH: C 0.1ppm (1 ppm = 10.38 mg/m 3 @ NTP)
PROPERTIES:
Issue 1: 15 August 1987 Issue 2: 15 August 1994
Solid; d (solid @ 25 °C) 4.93 g/mL;MP 113.6 °C; BP 185.2 °C; VP 40 kPa (0.305 mm Hg; 395 ppm) @ 25 °C; not combustible
SYNONYMS: None
SAMPLING SAMPLER:
MEASUREMENT
SOLID SORBENT TUBE (alkali-treated charcoal, 100 mg/50 mg)
TECHNIQUE:
ION CHROMATOGRAPHY
ANALYTE:
iodide ion ( I ¯ )
FLOW RATE:
0.5 to 1 L/min
DESORPTION:
3 mL 10 mM Na 2CO 3
VOL-MIN: -MAX:
15 L @ 0.05 ppm 225 L
INJECTION LOOP VOLUME:
SHIPMENT:
routine
SAMPLE STABILITY:
8 days @ 25 °C [1]
FIELD BLANKS:
2 to 10 field blanks per set
MEDIA BLANKS: 6 per sample set + 15 per lot of charcoal
50 µL
ELUENT:
10 mM Na 2CO 3; 3 mL/min
COLUMNS:
HPIC-AS4A anion separator; HPIC-AG4A anion guard; micromembrane suppressor
CONDUCTIVITY SETTING:
3 µS full scale
CALIBRATION:
standard solutions of KI in eluent
RANGE:
8 to 200 µg I 2 per sample [1]
ESTIMATED LOD:
1 µg I 2 per sample [1]
PRECISION (Sr):
0.071 @ 10 to 30 µg I2 per sample [1]
ACCURACY RANGE STUDIED:
0.74 to 2.1 mg/m 3 [1] (15-L air samples)
BIAS:
- 5.7%
ˆ ): 0.085 [2] OVERALL PRECISION (S rT ACCURACY:
± 22.4%
APPLICABILITY: The working range is 0.05 to 5 ppm (0.5 to 50 mg/m 3) for a 15-L air sample. The method is applicable to 15-min ceiling measurements.
INTERFERENCES: Particulate iodide salts, HI, or organic iodides may give positive interferences, but collection of these compounds on treated charcoal has not been investigated. Iodate, other halogens, nitrate, phosphate, and sulfate do not interfere.
OTHER METHODS: Better sensitivity (ppb range) has been found using amperometric detection (AS1 column [2] or AG2 and AS2 columns [3]). An AS5 column using 6 m M Na 2CO 3/0.8 mM paracyanophenol in 2% acetonitrile as eluent and either conductometric or amperometric detection yielded the best sensitivity [2].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
