Page:NIOSH Manual of Analytical Methods - 5019.pdf/1

 AZELAIC ACID

HOOC(CH2)7COOH

MW: 188.25

METHOD: 5019, Issue 2

5019

CAS: 123-99-9

RTECS: CM1980000

EVALUATION: PARTIAL

OSHA : no PEL NIOSH: no REL ACGIH: no TLV

Issue 1: 15 May 1985 Issue 2: 15 August 1994

PROPERTIES: solid; d 1.225 g/mL @ 25 °C; MP 106.5 °C; BP >360 °C (decomposes)

SYNONYMS: nonanedioic acid; 1,7-heptanedicarboxylic acid; lepargylic acid

SAMPLING SAMPLER:

FILTER (5-µm PVC membrane)

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FID

ANALYTE:

bis(trimethylsilyl)ester of azelaic acid

EXTRACTION:

5 mL ethanol; stand 20 min @ 70 °C; evaporate to dryness, derivatize and redissolve in pyridine BSTFA/TMCS in pyridine; 20 min @ 70 °C

FLOW RATE: 1 to 3 L/min VOL-MIN: -MAX:

200 L @ 5 mg/m 3 1000 L

SHIPMENT:

routine

DERIVATIZATION:

SAMPLE STABILITY:

not determined

INJECTION VOLUME: 1 µL

BLANKS:

2 to 10 field blanks per set

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

ACCURACY

250 °C; 250 °C; 190 to 250 °C; 6 °C/min or 200 °C isothermal

CARRIER GAS:

He, 39 mL/min

COLUMN:

3 m x 2-mm ID; 6% methyl silicone on 60/80 mesh Chromosorb WAW DMCS

ˆ rT): not determined OVERALL PRECISION (S

CALIBRATION:

analyte in pyridine

ACCURACY:

RANGE:

1 to 10 mg per sample

ESTIMATED LOD:

0.001 mg per sample [1]

PRECISION (Sr):

0.02 @ 1 to 10 mg per sample [1]

RANGE STUDIED:

not studied

BIAS:

not determined

not determined

APPLICABILITY: The working range is 2 to 20 mg/m 3 for a 500-L air sample. The measurement range can be lowered if adequate recoveries are found. The method may be applicable to other straight-chain aliphatic dicarboxylic acids.

INTERFERENCES: Moisture decomposes both the trimethylsilyl reagents and their corresponding derivatives.

OTHER METHODS: This is P&CAM 256 [2] in a revised format.

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