Page:NIOSH Manual of Analytical Methods - 2525.pdf/1

 n-BUTYL MERCAPTAN

CH3CH2CH2CH2SH

MW: 90.19

METHOD: 2525, Issue 2

2525

CAS: 109-79-5

RTECS: EK6300000

EVALUATION: FULL

OSHA: 0.5 ppm NIOSH: C 0.5 ppm ACGIH: 0.5 ppm (1 ppm = 3.69 mg/m3 @ NTP)

Issue 1: 5 May 1989 Issue 2: 15 May 1996

PROPERTIES: liquid; d 0.842 g/mL @ 25 C; BP 98 C; VP 4.7 kPa (35 mm Hg; 4.6% v/v) @ 20 C

SYNONYMS: butanethiol; 1-butanethiol; 1-mercaptobutane SAMPLING

MEASUREMENT TECHNIQUE:

GAS CHROMATOGRAPHY, FPD SULFUR MODE

FLOW RATE: 0.01 to 0.05 L/min

ANALYTE:

n-butyl mercaptan

VOL-MIN: -MAX:

1L 4L

DESORPTION:

1 mL acetone; stand 15 min

SHIPMENT:

routine

SAMPLER:

SOLID SORBENT TUBE (Chromosorb 104, 150 mg/75 mg)

INJECTION VOLUME:

5 µL 150 C 200 C 140 C

SAMPLE STABILITY:

at least 7 days @ 25 C [1]

TEMPERATURE-INJECTOR: -DETECTOR: -COLUMN:

BLANKS:

2 to 10 field blanks per set

COLUMN:

glass, 1.2 m x 2-mm ID, packed with 60/80 mesh Chromosorb 104

CARRIER GAS:

N2, 50 mL/min

CALIBRATION:

standard solutions of n-butylmercaptan in acetone

RANGE:

20 to 200 µg per sample [2]

ACCURACY RANGE STUDIED: 17 to 74 mg/m3 [1] (1.5-L samples) BIAS:

- 2% [1] ESTIMATED LOD: 3 µg per sample [1]

OVERALL PRECISION ( ACCURACY:

rT):

PRECISION ( r):

0.062 [1]

0.015 @ 30 to 110 µg per sample [1]

± 14.2%

APPLICABILITY:The working range is 5 to 50 mg/m3 (1.4 to 14 ppm) maximum sample size is based on the capacity of the Chromosorb 104 to collect vapors of n-butyl mercaptan in air at high relative humidity (94%) [1]. Smaller concentrations may be determined if desorption efficiency is adequate.

INTERFERENCES:None identified.

OTHER METHODS:This revises NIOSH Method S350 [2].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 5/15/96