What is the best way to do trace metal sampling?
1. All samplers contaminate or distort in some way.
• Plastics may leach metals from ultraviolet inhibitors, metal-organic plasticizers, (rarely) metal catalysts.
• Teflon has a rough porous surface into which ions, fine charged particles, and very fine particles may become attached. Errors may occur in your first sample due to these trapped trace elements.
• Metal and glass may dissolve into the sample, usually at the nanogram/ liter level.
• The sample may react with the sampler, causing errors and damage to the sampler.
2. Are you using the right sampler? Is the sampler clean? Have you run a test blank?
3. Selecting a particular sampler may depend upon the material(s) sought or environment being sampled.
4. Alconox lab detergent is suggested to remove oil and most soils. Rinse. A 3% acid solution (HCl or HN03) will remove detergent. Rinse at least once, using distilled water. Air dry if storing.
5. Run a test blank by filling the sampler with distilled water, holding for at least as long as the sample will be held in the sampler, and running test analysis.
6. Air dry and store in a clean plastic bag until needed.