Heptane (method no. S89), hexane (method no. S90), octane (method no. S378), pentane (method no. S379), in NIOSH/OSHA standards completion program
S89-1 - S89-9, S90-1 - S90-9, S378-1 - S378-9, S379-1 - S379-9
NIOSH standard analytical methods are described for determining hexane (110543), pentane (109660), heptane (142825), or octane (111659) in the air, and condensed method descriptions and validation reports with test data are included. Each description includes the principle of the method, range and sensitivity, interference, precision and accuracy, advantages and disadvantages of the method, apparatus, reagents, procedure, analysis of samples, determination of desorption efficiency, calibration and standards, calculations and references. All four methods entail trapping the alkane vapors by drawing a known volume of air through a charcoal tube, desorption of the analyte with carbon-disulfide, and separation and analysis using a gas chromatograph with a flame ionization detector. A calibrated personal sampling pump is used. The method for hexane has been validated over the range of 877 to 3679 milligrams per cubic meter for a 4 liter sample at 17 degrees centigrade and 764 millimeters of mercury atmospheric pressure; that for pentane is 1476 to 6190 milligrams per cubic meter for a 2 liter sample at 24 degrees centigrade and 769 milligrams of mercury; that for heptane is 968-4060 milligrams per cubic meter for a 4 liter sample at 24 degrees centigrade and 748 millimeters of mercury; and that for octane is 1050-4403 milligrams per cubic meter for a 4 liter sample at 20 degrees centigrade and 758 millimeters of mercury. The respective air quality standards (8 hours time weighted average) are 500ppm (1800 milligrams per cubic meter), 1000ppm (2950 milligrams per cubic meter), 500ppm (2000 milligrams per cubic meter), and 500ppm (2350 milligrams per cubic meter).