Page:NIOSH Manual of Analytical Methods - 6005.pdf/1

 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