Page:NIOSH Manual of Analytical Methods - 2550.pdf/1

 BENZOTHIAZOLE IN ASPHALT FUME

C7H5SN

MW: 135.19

METHOD: 2550, Issue 1

CAS: 95-16-9

2550

RTECS: DL0875000

EVALUATION: PARTIAL

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

PROPERTIES:

Issue 1: 15 January 1998

liquid; d 1.246 g/mL @ 20 C; MP 2 C; BP 231 C; vp 4.5 kPa (34.0 mm Hg) @ 131 C; vapor density 4.7 (air = 1)

SYNONYMS: Benzosulfonazole; 1-Thia-3-azaindene SAMPLING SAMPLER:

FILTER + SORBENT TUBE (2-µm, 37-mm, PTFE + XAD-2, 100/50 mg)

FLOW RATE:

1.0 to 2.0 L/min

VOL-MIN: -MAX: 960 L

480 L

SHIPMENT:

Ship samples with refrigerant packs

SAMPLE STABILITY:

ca. 28 days @ 4 C [1]

BLANKS:

2 to 10 field blanks per set

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, SULFUR CHEMILUMINESCENCE DETECTOR

ANALYTE:

benzothiazole

DESORPTION:

4 mL hexane; stand 30 minutes

INJECTION VOLUME:

1 µL

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

275 C 1000 C 50 C, 1.0 min; 15 C/min to 225 C, hold 15 min; 6 C/min to 320 C

CARRIER GAS:

Helium @ 2.4 mL/min (splitless)

COLUMN:

capillary, 30 m, 0.32-mm ID, 1.0-µm film, 100% dimethyl polysiloxane, Rtx-1® or equivalent

CALIBRATION:

solutions of benzothiazole in hexane

RANGE:

1.0 to 250 µg per sample

ACCURACY

RANGE STUDIED:

not studied

BIAS:

not determined

OVERALL PRECISION ( ACCURACY:

rT

): not determined not determined

ESTIMATED LOD: 0.30 µg per sample (instrumental) [1] PRECISION ( r):

0.5 @ 1.0 to 20 µg per sample

APPLICABILITY: The working range is 0.002 to 0.5 mg/m3 for a 480-L air sample. This method was developed to determine benzothiazole in the presence of other sulfur compounds in asphalt fume samples (see Figure 1). This method may be used in conjunction with method 5800, Polycyclic Aromatic Compounds, Total [2]. An aliquot of the desorbed sample from method 5800 can be analyzed for benzothiazole by this method, since the sampler and desorbing solvent are the same.

INTERFERENCES: None identified; however, compounds with a similar retention time may interfere. Positive identification may be confirmed by dual column chromatography using an appropriate alternative capillary column. Identification can also be confirmed by mass spectrometry.

OTHER METHODS:None identified.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition