170135_inorganicventures_flipping

8:1 Environmental Contamination

Overview:

§ Environmental contamina.on is caused by par.culate and/or gaseous ma7er in the air. § It has been reported that air in an analy.cal laboratory can contain up to 200 μg/m3 of par.culate ma7er containing Ca, Si, Fe, Na, Mg, K, Tl, Cu, Mn , and lesser amounts of other elements 1 . § Normal rural area airborne par.cle counts have been reported to be 1,400,000/m3 for par.cles greater than 0.5 μm. § Normal metropolitan area par.cle counts have been reported to be 53,000,000/m3 for par.cles greater than 0.5 μm.

1. T. Murphy, Na.onal Bureau of Standards Special Publica.on 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.