This fifth in a blog series on robustness and its role in enhancing lab optimization processes focuses on data management. The series takes a critical look at the term “robustness” and describes how it relates to a portfolio of analytical instruments (hardware and software) in quantifiable terms and benefits. The working definition for robustness (described in Part 1 of the series) includes three aspects: measurement, instrument, and process. The following describes an example of measurement robustness that centers on chromatography data management software, or more specifically electronic workflows.
Fundamentally, all chromatography workflows (IC, LC, and GC) are similar: samples are injected, chromatographic separations are performed, signals are captured, and results are generated. Where workflows differ is in the details – such as the instrument conditions, injection sequence requirements, and the techniques by which results are calculated. These differences create complexity, introduce variability, increase the risk of errors, and ultimately reduce laboratory productivity. Electronic workflows provide a means to address the details and minimize the differences in variability.
Thermo ScientificTM eWorkflowsTM minimize the differences in variability by simplifying and automating the laboratory process. An eWorkflow is composed of a series of rules that captures all the unique aspects of a chromatography workflow and guides the operator through a minimal number of steps to run it. These steps include the following;
A workflow (either pre-configured or new)
An instrument (single or multiple chromatography systems)
The number of unknown samples and other samples like standards and blanks
Chromatographic conditions (column temperature, flow rate, detector parameters – including mass spectrometry)
The sequence (i.e., name, location, methods, report, structure, customer variables, related documents)
System suitability testing (for verifying chromatographic resolution and reproducibility)
A final report (automatically created upon completion of the sequence (print-out or electronic)
What Is Their Value?
Today’s test laboratories are businesses spanning multiple industries and chromatograph techniques. A chromatography data system is expected to manage all the analytical processes from instrument control to raw data storage and processing right through to generating final results – and follow standard operating procedures (SOPs). eWorkflow are a vital component in addressing these challenges.
The following provides an example of a robustness study aimed at verifying chromatographic resolution and reproducibility and making “go-no go” decisions based on pre-configured conditions with the following 4 capabilities;
Improve reliability by reducing errors
Increase throughput by reducing delays
Reduced sample loss by detecting system failure
Improve workflow efficiency by automating the sample to spec comparison
How Are They Used?
As stated above, eWorkflows have the ability to include everything required to run an analysis. This includes standard, quality control and system suitability calculations and the ability to make intelligent run decisions as the sequence executes based on their results. To illustrate this, Figure 1 shows the Chromeleon Chromatography Studio displaying a chromatogram, processing method (middle pane) and computed results (bottom pane). The analyte, an active ingredient in the tablets, is analyzed as a percentage of the expected amount. The results are automatically compared to preset pass/fail thresholds and regulatory requirements.
Figure 1. A Chromeleon processing method configured with FDA recommended suitability tests
The processing method was configured to perform the five system suitability tests recommended by the FDA. For example, Test 1 checks that the resolution of the acetophenone peak versus the next peak is > 2. When acquiring a sequence of samples using this processing method, the “Fail-Action” (column 😎 in the method pane is configured to halt the sequence if the test fails to meet this criterion. For example, the Theoretical Plates test has failed, since the computed value (1278) is less than the test criterion (2000). This is show in the “Result” (column 9) for each test. In addition to pass and fail, the system also identifies when the value cannot be calculated. The %RSD test is “Not Executed” because the displayed injection is only the second line of the sequence, meaning that an insufficient number of samples (2 out of 5) have been analyzed to perform this calculation.
By automating some of the most repetitive and time consuming step found in a laboratory, eWorkflows enhance lab productivity by reducing errors and effectively getting it right the first time.
Keep an eye out for the next blog in the robustness series that will center on LIMS. In the meantime, please visit our growing blog library on analytical instrument robustness in Analyte Guru by typing robustness in the search window.