Gravimetric Sample Preparation
Sample preparation is an important part of an analytical workflow. However, it usually consists of tedious and time-consuming manual operations. Unfortunately, labor-intensive manual processing also constitutes a high risk of error or variability, which can lead to out-of-specification (OOS) or out-of-tolerance (OOT) results (test results which fall outside of specification or tolerance acceptance criteria). Variability in sample preparation influences the accuracy of the final results of the analysis, so it is crucial to identify and eliminate any potential sources of errors before they can have an impact on downstream results.
An article published some years ago in LC/GC magazine investigated two aspects of an analytical laboratory workflow: firstly, what proportion of an analysts' time is spent on the different steps in an analytical workflow and secondly, what are the main sources of OOS errors. The results from this survey indicated that more than half (61%) of an analysts' time is spent on sample processing, and almost half (49%) of the OOS errors can be attributed to either sample processing or operator error.