Page:NIOSH Manual of Analytical Methods - 5029.pdf/1
4,4'-METHYLENEDIANILINE
CH2(C6H4NH2)2
MW: 198.27
METHOD: 5029, Issue 2
5029
CAS: 101-77-9
RTECS: BY5425000
EVALUATION: PARTIAL
OSHA : no PEL NIOSH: lowest feasible; carcinogen ACGIH: 0.1 ppm (skin); suspected human carcinogen (1 ppm = 8.11 mg/m 3 @ NTP)
PROPERTIES:
Issue 1: 15 August 1990 Issue 2: 15 August 1994
solid; MP 92 °C; BP 399 °C; VP 0.2 x 10 -7 kPa (1.5 x 10 -7 mm Hg) @ 25 °C
SYNONYMS: p,p'-diaminodiphenylmethane; MDA.
SAMPLING
MEASUREMENT
SAMPLER:
FILTER (acid-treated glass fiber, 37-mm)
TECHNIQUE:
HPLC, UV AND ELECTROCHEMICAL DETECTION
FLOW RATE:
1 to 2 L/min
ANALYTE:
4,4'-methylenedianiline (MDA)
VOL-MIN: -MAX:
10 L @ 0.1 ppm 1000 L
EXTRACTION:
0.1 N KOH In methanol
SHIPMENT:
transfer filter to glass vial; extract with 4 mL 0.1 N methanolic KOH before shipping
INJECTION VOLUME:
25 µL
SAMPLE STABILITY:
stable at least 60 days @ 20 °C [1]
FIELD BLANKS:
2 to 10 field blanks per set
MEDIA BLANKS:
at least 3 per set
ACCURACY RANGE STUDIED:
not studied
BIAS:
not determined
ˆ ): not determined OVERALL PRECISION (S rT ACCURACY:
not determined
MOBILE PHASE:
0.1 N sodium acetate in acetonitrile/70% H 2O @ 1 mL/min
30%
COLUMN:
C 18 column, 4-µm particle size
DETECTOR:
UV, 245 nm; electrochemical (ECHD), glassy carbon electrode at +0.75 to +0.85 V vs. Ag/AgCl electrode
CALIBRATION:
MDA in 0.1 N methanolic KOH
RANGE: UV: ECHD:
0.3 to 5 µg per sample [1] 0.025 to 0.5 µg per sample [1]
ESTIMATED LOD: 0.12 to 1.2 µg per sample [4] PRECISION (Sr):
0.027
ESTIMATED LOD: UV: 0.12 µg per sample ECHD: 0.007 µg per sample [1]
APPLICABILITY: The working range is 0.025 ppb to 1.2 ppm (0.0002 to 10 mg/m 3) for a 100-L air sample, and the method is applicable to STEL measurements. The method is specific for MDA and the use of UV and electrochemical detectors in serie s gives greater reliability to the analysis, and allows a wide measurement range. The method has been applied to wipe samp les.
INTERFERENCES: 4,4'-Diphenylmethane diisocyanate (MDI) will interfere owing to its conversion to MDA on the acid-treated glass fiber filter. Other aromatic amines do not interfere.
OTHER METHODS: Methods with acetylation, and the determination of the acetic anhydride derivative of MDA either by HPLC/UV [2] or by GC/EC (OSHA Method 57) [3] have been reported.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94