National Institute for Occupational Safety and Health

“ The LOQ for pentamidine isethionate on a PVC filter (50 ng) was the lowest level at which recovery was acceptable (>75%) . The LOD and LOQ for pentamidine isethionate on the interior surface of the front piece of a cassette filter holder were 7 and 24 ng, respectively. A standard solution of pentamidine isethionate in eluent at a concentration of 100 ng/mL was stable for a period of more than 3 months during storage at 0 °C in the dark. Smith states that for killing wet and dry tuberculosis bacteria, 95% ethanol and 50% ethanol, respectively, are most active . ”

“ Working standards in eluent are stable for more than 3 months when stored in the dark at 0 °C. b. Analyze together with samples and blanks (steps 15 through 17) . c. Prepare a calibration graph (peak height or area versus concentration of pentamidine isethionate) . Determine recovery (R) at least once for each lot of PVC membrane filters used for sampling in the calibration range (step 12) . Prepare three filters at each of five levels plus three media blanks. a. Place filters into 50-mL beakers. b. By means of a 10-μL syringe, fortify each filter with recovery solution. ”

“ Consequently, live tuberculosis bacteria may be collected during air sampling. Inhalation of tuberculosis bacteria in aerosols is the only notable means of transmission which results in infection. Infection does not result from skin contact. Thus, the analyst is safe as long as aerosols are not produced. The use of alcohol to kill tuberculosis bacteria simply increases the degree of safety. ”