Page:NIOSH Manual of Analytical Methods - 8302.pdf/1

 MBOCA in urine (H2NC6H3Cl)2CH2

MW: 267.16

METHOD: 8302

8302

CAS: 101-14-4

RTECS: CY1050000

EVALUATION: PARTIAL

BIOLOGICAL INDICATOR OF:

Issue 1: 15 February 1984 Issue 2: 15 August 1994

exposure to 4,4'-methylenebis(2-chloroaniline)

SYNONYMS: MOCA; di-(4-amino-3-chlorophenyl)methane; 4,4'-methylenebis(2-chloroaniline) SAMPLING

MEASUREMENT

SPECIMEN:

2 urines (pre- and post-exposure)

TECHNIQUE:

GAS CHROMATOGRAPHY, ECD

VOLUME:

50 to 100 mL in polyethylene screw-cap bottles containing preservative

ANALYTE:

heptafluorobutyryl MBOCA derivative

EXTRACTIONS:

MBOCA and analyte

INJECTION VOLUME:

1 µL

PRESERVATIVE: 3 mL of 30% (w/w) citric acid solution SHIPMENT:

freeze urine and ship in dry ice in an insulated container

STABILITY:

stable for 2 days @ 25 °C and for 1 month @ -20 °C

TEMPERATURE-INJECTOR: -DETECTOR: -COLUMN:

200 °C 300 °C 1 min @ 90 °C; 35°/min; 4 min @ 250 °C

CONTROLS: collect urine from non-exposed workers COLUMN:

SE-54 capillary column, 30 m x 0.25-mm ID fused silica

CARRIER GAS:

5% methane in argon, 40 mL/min

CALIBRATION:

control urine spiked with MBOCA; MDA as internal standard

QUALITY CONTROL:

frozen pooled urine; correct for creatinine content

RANGE:

10 to 250 µg/L urine

ESTIMATED LOD:

1 µg/L urine

RECOVERY:

89% (100 µg/L of urine); 79% (4 to 25 µg/L urine)

PRECISION (Sr):

0.08

ACCURACY:

± 27 to 37%

APPLICABILITY: MBOCA is commonly found in the urine of humans exposed to the compound in the plastic industry. Despite the extensive metabolism of MBOCA in the rat, analysis of the urine of exposed workers showed only MBOCA [1]. This GC-EC D method is useful in screening workers exposed to MBOCA.

INTERFERENCES: Imipramine has a similar retention time. A careful work history/questionnaire is suggested.

OTHER METHODS: This revises P&CAM 342 [2] and Method 8302 (dated 2/15/84). This method is 40-fold more sensitive than the method in the Special Hazard Review [3]. A similar, less sensitive method using GC-FID has been described [4].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94