MERCAPTANS, METHYL-, ETHYL-, and n-BUTYL- 2542 CH3SH CH3CH2SH CH3CH2CH2CH2SH
MW: 48.11 MW: 62.13 MW: 90.19
METHOD: 2542, Issue 1
CAS: 74-93-1 CAS: 75-08-1 CAS: 109-79-5
RTECS: PB4375000 RTECS: KI9625000 RTECS: EK6300000
EVALUATION: PARTIAL
OSHA: Table 1 NIOSH: Table 1 ACGIH: Table 1
Issue 1: 15 August 1994
PROPERTIES: Table 1
SYNONYMS: Methyl mercaptan: methanethiol; mercaptomethane; methyl sulfhydrate Ethyl mercaptan: ethanethiol; mercaptoethane; ethyl sulfhydrate n-Butyl mercaptan: butanethiol; 1-mercaptobutane; 1-butanethiol
SAMPLING SAMPLER: FILTER (glass fiber, 37-mm, impregnated with mercuric acetate)
MEASUREMENT TECHNIQUE:
GAS CHROMATOGRAPHY, FPD SULFUR MODE
ANALYTE:
methyl, ethyl, and n-butyl mercaptans
EXTRACTION:
20 mL HCl (25% v/v) plus 5 mL 1,2dichloroethane, 2 min
FLOW RATE: 0.1 to 0.2 L/min VOL-MIN: -MAX:
10 L @ 0.5 ppm 150 L
SHIPMENT: protect samples from light [1,2] SAMPLE STABILITY: at least 3 weeks @ 25 °C BLANKS:
1 µL
TEMPERATURE-INJECTION: 250 °C -DETECTOR: 250 °C -COLUMN: 30 °C 2 min, 15 °C/min, 200 °C
2 to 10 field blanks per set ACCURACY
RANGE STUDIED:
Table 2
BIAS:
not determined
OVERALL PRECISION ( ): Table 2 ACCURACY:
INJECTION VOLUME:
not determined
COLUMN:
narrow-bore, fused-silica capillary, 30 cm × 0.25-mm ID, 1 µm DB-1
CARRIER GAS:
He, 1.0 mL/min; makeup gas: N2, 20 mL/ min
CALIBRATION:
standard solutions of mixed mercaptans in 1,2-dichloroethane
RANGE:
Table 2
ESTIMATED LOD: Table 2 PRECISION ( ):
Table 2
APPLICABILITY: The working ranges are 0.2 to 10 ppm for a 20-L air sample for all three mercaptans [1–4]. INTERFERENCES: Dimethyl disulfide, diethyl disulfide, and dibutyl disulfide may interfere [2–4]. OTHER METHODS: This is a modification of OSHA Method 26 for methyl mercaptan with the addition of ethyl- and n-butyl mercaptan [2].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition
