per trillion (ppt) in air that is extracted by water or other solvent to determine the presence of the trace molecules of interest to a required density approximating 1 trace molecule of interest for detection at one ppt for impingement materials made from nano-structures of precious metals. ...
Solid-phase extraction (SPE) is an effective way to prepare samples in chemistry. A sample collection and analysis gap can be closed using SPE as one of the methods. It is rarely used with no further preparation steps, such as dilution or pH adjustment [1,2,3]. Similar to liquid–liquid...