Purpose: To evaluate the active air sampler performance according to ISO 14698-1:2003 Annex B guideline.
Methods: Study was conducted by an independent expert public laboratory, using Trypticase Soy agar ICR+ media plates on tested and reference systems. Physical efficiency: Bacillus atrophaeus spores in Potassium Iodide (KI) solutions were aerosolized and sampled. KI concentration (0 to 7% (w/v)) determined average particles size in a range of 1 µm to 6 µm mass mean diameter. Result expressed as recovery percentage of colonies counted on tested system versus reference membrane impaction air sampler. Biological efficiency: mixed suspensions of B. atrophaeus (BA) spores and Staphylococcus epidermidis (SE) cells were aerosolized and sampled. Result expressed as recovery percentage of counted colonies ratio SE/BA sampled by the active air sampler versus the ratio obtained on the reference Casella slit sampler.
Results: Physical efficiency (ten repeats per size): 84.2±14.8% at 1 µm mass mean diameter, 85.8±11.2% at 1.3 µm, 94.2±10.9% at 2.2 µm and 99.7±9.7% at 5.4 µm. Biological efficiency (twenty repeats): 76.48±26.42%.
Significance: Physical efficiency indicates high recoveries at all sizes. Biological efficiency indicates effectiveness at sampling cells without significant loss of viability. Results demonstrate that the MAS-100 VF is an efficient solution for capturing bacteria-laden air particles repeatably and reproducibly, and could be incorporated into the Environmental Monitoring Program of the FSMA Food Safety Plan for reliable environmental air sampling.