Sampling: Sample collection is a critical stage of analysis which can ultimately determine the overall effectiveness of the result. A poor sampling procedure often cannot be recovered by enhanced software processing or optimization of other parameters. Undesirable outcomes from poor sampling could result in reduction in performance and reduced operator confidence, which may increase the probability of false alarms. Furthermore, improper sampling may lead to reduction in sensor lifetime or interruption of analysis due to maintenance. For extraction of polar organics or other molecules of interest present at very low concentrations in solid samples, an additional liquid extraction step is also REQUIRED.