Page:NIOSH Manual of Analytical Methods - 2542.pdf/4

 MERCAPTANS, METHYL-, ETHYL-, and n-BUTYL-: METHOD 2542, Issue 1, dated 15 August 1994 - Page 4 of 4

REFERENCES: [1]	 Xue, Zhi-Lun, Backup Data Report for Methyl, Ethyl, and n-Butyl Mercaptans (NIOSH/DPSE, unpublished, October, 1991). [2]	 OSHA Analytical Laboratory, Method 26, Methyl Mercaptan, February 1981. [3]	 Knarr, R. and Rapport, S.M., Determination of Methanethiol at Parts-per-Million Air Concentration by Gas Chromatography, Anal. Chem., 52, 733-736 (1980). [4]	 Knarr, R. and Rapport, S.M., Impregnated Filters for the Collection of Ethanethiol and Butanethiol in Air, Am. Ind. Hyg. Assoc. J., 42, 839-941 (1981). [5]	 Material Safety Data Sheet, #504 Butyl Mercaptan, General Electric, Schenectady, NY 12305 (1982). [6]	 NIOSH/OSHA Occupational Health Guidelines for Occupational Hazards, U.S. Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981), available as GPO Stock #017-033-00337-8 from Superintendent of Documents, Washington, DC 20402. METHOD REVISED BY: Pratima Shah, NIOSH/DPSE, and Zhi-Lun Xue. TABLE 1. GENERAL INFORMATION Exposure Limits (ppm) Compound Methyl mercaptan Ethyl mercaptan n-Butyl mercaptan

OSHA C 10 C 10 10

NIOSH C 0.5/15 min C 0.5/15 min C 0.5/15 min

ACGIH 0.5 0.5 1.8

1 ppm = mg/m³ @ NTP 2.0 2.6 3.7

Density @ 20 °C (g/mL) 0.866 0.839 0.834

BP (°C) 6.2 35 98.4

VP kPa (mm Hg) > 1 atm 58.9 (442) 4.7 (35)

TABLE 2. EVALUATION DATA

Compound Methyl mercaptan Ethyl mercaptan n-Butyl mercaptan

Range Studied* (mg/m³) 1.0 to 4.0 1.3 to 5.6 1.8 to 7.4

Measurement Range (µg/sample) 10 to 50 10 to 50 20 to 70

Precision 0.055 0.059 0.063

LOD (µg/sample) 4 5 7


 * 180-L samples

Figure 1. Sample spiking and collection system. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

Overall Precision 0.091 0.097 0.086