Ten NIOSH Analytical Methods - Phosphine.
NIOSH 1979 Apr:41 pages
The NIOSH validated method for the determination of phosphine (12768820) is described. Sixteen liters of air (flow rate at 0.01 to 0.2 liters per minute) is drawn through tubes containing mercuric cyanide impregnated silica gel. The contents of the tubes is extracted with 10 milliliters (ml) of a solution containing 0.316 grams (g) potassium-permanganate plus 6ml concentrated sulfuric-acid per liter for 90 minutes in a water bath at 65 to 70 degrees-C. The extracts are treated with 1ml of a solution of 7.9g ferrous-ammonium- sulfate plus 1ml concentrated sulfuric-acid per 100ml. To this is added 7.5ml of a solution of 49.4g ammonium-molybdate plus 112ml concentrated sulfuric-acid per liter. The solution is extracted with 25ml of a 1 to 1 toluene/isobutanol solution. Ten ml of the nonaqueous layer are treated with 10ml alcoholic sulfuric-acid solution, 50ml concentrated sulfuric-acid plus 950ml methanol. Twenty five drops of stannous-chloride reagent, 0.4g in 50ml glycerol, are added. The absorbance of the solution is immediately measured at the wavelength of 625 nanometers. The concentration is determined from a calibration curve. The method is validated for phosphine concentrations of 0.195 to 0.877 milligrams per cubic meter (mg/m3), with a standard deviation of 0.0119mg/m3.
NIOSH-Author; NIOSH-Analytical-Method; Analytical-Method; Standards; Sampling; Standards-Completion-Program; SCP; Set-7; Colorimetry; Adsorbents;
NTIS Accession No.
Division of Physical Sciences and Engineering, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, 41 pages, 5 references