Basic Training 4th Annual ICP Conference

8:1 Environmental Contamination

Overview:

§ Environmental contamination is caused by particulate and/or gaseous matter in the air. § It has been reported that air in an analytical laboratory can contain up to 200 μg/m3 of particulate matter containing Ca, Si, Fe, Na, Mg, K, Tl, Cu, Mn , and lesser amounts of other elements 1 . § Normal rural area airborne particle counts have been reported to be 1,400,000/m3 for particles greater than 0.5 μm. § Normal metropolitan area particle counts have been reported to be 53,000,000/m3 for particles greater than 0.5 μm.

1. T. Murphy, National Bureau of Standards Special Publication 422, "Accuracy in Trace Analysis: Sampling, Sample Handling, and Analysis", Proceedings of the 7th IMR Symposium.

8:2 Environmental Contamina3on

Reducing Environmental Contamina3on:

Use the chemical blank as the performance criteria. Dealing with environmental contamina8on is expensive. Therefore, reduce the blank to the lowest possible value by elimina8ng contamina8on from the sample container, the chemist, and sample prepara8on apparatus. v Separate the sample prepara8on and handling area from all other areas. v Eliminate as many foreign objects as possible from the prepara8on area (i.e. Motorized objects such as s8rring plates). v Use all-plas8c hoods. v Keep the sample out of the hood area as much as possible.