Page:NIOSH Manual of Analytical Methods - 8324.pdf/1

 3-BROMOPROPIONIC ACID in URINE

8324

metabolite of 1-bromopropane

FORMULA: C3H5BrO2 METHOD: 8324, Issue 1

MW: 152.97 CAS: 590-92-1 EVALUATION: FULL

Published limits and guidelines using this compound as a marker: OSHA:	 None NIOSH:	 None Other OELs: [1,2,3,4]*

BIOLOGICAL INDICATOR OF:

RTECS: UE7875000 Issue 1: 29 August 2014

Exposure to 1-bromopropane

PROPERTIES:	 Solid; d 1.48 g/mL at 25 oC; MP 58-62 oC

SYNONYMS: β-Bromopropionic acid; 2-carboxyethylbromide. SAMPLING SPECIMEN: 	 Urine VOLUME:

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, MASS SPECTROMETRY with SELECTED ION MONITORING (GC/MS-SIM)

ANALYTE:

tert-butyldimethylsilane derivative of 3-bromopropionic acid

EXTRACTION:

Liquid-liquid extraction (LLE)

INJECTION VOLUME:

0.5 μL, splitless

At least 15 mL

PRESERVATIVE:

None added. Refrigerate or freeze upon collection.

SHIPMENT: 	 Ship cold or frozen with ice or dry ice. Freeze upon receipt at the laboratory. SAMPLE STABILITY:	 Stable in frozen urine for at least 30 days. CONTROLS:	 Urine specimens obtained from non-exposed individuals. ACCURACY

TEMPERATURES INJECTION: 200 oC COLUMN:

60 oC initial, 4 oC/min to 180 oC,15 oC/min to 255 oC, post-run at 270 oC for 5 min

DETECTOR:

Source 230 oC, Quadrupole 150 oC; Solvent delay, 15 min

RANGE STUDIED:

RUN TIME:

Approximately 50 minute cycle time

Table 1

CARRIER GAS:

Helium, 0.8 mL/min constant flow

BIAS:

None established

COLUMN:

Capillary, fused silica, 100% dimethylpolysiloxane, 50 m X 0.20 mm (ID), 0.33 μm film thickness

CALIBRATION:

Analyte in control urine; with internal standard

PRECISION:	 Table 1 RECOVERY ACCURACY:	 Full recovery (95% overall) was established by a spiked urine recovery, overall RSD was +3.1% (Table 1). The definitions of precision and accuracy in this method are those utilized by the US Food and Drug Administration [5].

QUALITY CONTROL:

RANGE:

At least one level of spiked urine sample prepared from a separately weighed stock solution 2.0 to 100 μg/mL

ESTIMATED LOD: Approximately 0.01 μg/mL (IUPAC) [6]. 0.1 μg/mL is the lowest calibration standard. APPLICABILITY: 3-Bromopropionic acid (3-BPA) has been reported to be a rat metabolite [7] and is a potential human biomarker for exposure to 1-bromopropane. This method measures the quantity of free 3-BPA in urine. 1-Bromopropane is used as an industrial solvent. In one limited study, 3-BPA was not detected in individuals exposed to low levels of 1-bromopropane [8]. INTERFERENCES: None found or identified. OTHER METHODS:	This method is from the one described by B’Hymer and Cheever [9] and further investigated by Mathias, et al. [8].

NIOSH Manual of Analytical Methods (NMAM), Fifth Edition