DYES, BENZIDINE-, o-TOLIDINE-, o-DIANISIDINE-
Table 1
MW: Table 1
METHOD: 5013, Issue 2
CAS: Table 1
RTECS: Table 1
EVALUATION: PARTIAL
OSHA : no PEL NIOSH: lowest feasible; carcinogen ACGIH: carcinogen
PROPERTIES:
5013
Issue 1: 15 May 1989 Issue 2: 15 August 1994
colored powders; water soluble; VP not significant
SYNONYMS: Table 1.
SAMPLING SAMPLER:
FILTER (5-µm PTFE membrane)
MEASUREMENT TECHNIQUE:
HPLC, UV DETECTION
ANALYTE:
benzidine, o-tolidine, o-dianisidine
DESORPTION:
2 mL H 2O; ultrasonic
REACTION:
reductive cleavage of dye to free amine with sodium hydrosulfite
FLOW RATE: 1 to 3 L/min VOL-MIN: -MAX:
150 L @ 0.1 mg/m 3 500 L
SHIPMENT:
keep samples dry and cool; protect from light
SAMPLE STABILITY: FIELD BLANKS: BULK SAMPLE:
INJECTION VOLUME:
10 µL
at least 7 days @ 25 °C in the dark MOBILE PHASE:
60% methanol/40% phosphate buffer; ambient temperature
COLUMN:
10 cm x 8-mm ID, Waters Radial Pak C 18, 10-µm particles, with Radial Compression Module or equivalent
DETECTOR:
UV detector @ 280 nm
CALIBRATION:
solutions of benzidine, o-tolidine and odianisidine in methanol
RANGE:
ca. 15 to 250 µg per sample (Table 1)
2 to 10 field blanks per set
include 1 bulk sample for each dye present on the filter ACCURACY
RANGE STUDIED:
not studied
BIAS:
none identified
ˆ ): not evaluated OVERALL PRECISION (S rT ACCURACY:
not determined
ESTIMATED LOD: 3 µg benzidine per sample [1] PRECISION (Sr):
0.04 to 0.08 [2,3]
APPLICABILITY: The working range is ca. 0.06 to 8 mg/m 3 for a 250-L air sample. This method determines benzidine, o-tolidine or o-dianisidine from dyes based on these amines, but will not distinguish different dyes based on the same amine. The metho d will not distinguish benzidine obtained from reduction of the dyes and free benzidine in the dye formulation.
INTERFERENCES: Aniline, azobenzene, p-aminophenol, p-phenylenediamine or p-nitroaniline do not interfere in the measurement when present in equimolar amounts.
OTHER METHODS: This revises P&CAM 325 [2,3]. P&CAM 234 [4,5], a general colorimetric method for diazonium salts and azo dyes, has not been revised.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
