7.1 Sampling Techniques
Swabs and Wipes
Swabbing is a widely used sampling technique. Swabs may be saturated with solvent (e.g., water, alcohol), aiding the solubilization and physical removal of surface residues, or used dry.
Advantages:
- dissolves and physically removes sample
- adaptable to a wide variety of surfaces
- economical and widely available
- may allow sampling of a defined area
- applicable to active, microbial, and cleaning agent residues
Limitations:
- an invasive technique that may introduce fibers
- results may be technique dependent
- swab material and design may inhibit recovery and specificity of the method
- evaluation of large, complex and hard-to-reach areas difficult (e.g., crevices, pipes, valves,
large vessels)
- subject to the vagaries of site selection
