Chemistry Reference
In-Depth Information
3.4.2 A
utomAted
hPlc m
ethod
d
eveloPment
S
yStemS
Automation of the optimization is a natural extension of a methodical, planned
method development process. Why automate? The desire to automate method devel-
opment stems from the simple reason that traditional manual HPLC method devel-
opment is a labor-intensive, time-consuming, and often-imprecise process, resulting
in lost time, money, and productivity because it can take weeks to develop a method
manually. Automated method development systems provide an alternative to the tra-
ditional slow, manual, and unreliable trial-and-error method development approach
and can often reduce method development time to as little as a few hours. In addition,
automated systems can often evaluate a larger number of conditions, thus improving
the robustness of the method.
Systems have been developed that utilize external modeling software (Table 3.1;
e.g., DryLab, Molnar-Institute, Berlin, Germany; or LC Simulator or AutoChrom,
Advanced Chemistry Development, Toronto, Ontario, Canada) that either partially
or completely automate the HPLC method development process (8-14). These the-
ory-based modeling software programs allow analysts to evaluate a much wider
range of experimental conditions than would ever be practical by running experi-
ments in the laboratory, significantly decreasing method development and optimi-
zation time. With this type of software, the effects of variables, either alone or in
combinations—for example, organic concentration, pH, temperature, gradient slope,
and buffer concentration—can be easily observed. In addition, analysts can
• Evaluate method robustness to decrease the cost of revalidating methods
• Transfer gradient methods from one instrument to another, eliminating
method redevelopment time
• Model two separation variables simultaneously for faster method development
• Shorten run times to increase sample throughput
• Train new chromatographers and establish laboratory method develop-
ment SOPs
Figure 3.7 shows a screenshot from DryLab software during the development of a
separation of some nitroaromatics. Screens such as this in the software can be used
to model separations, including different solvent compositions and column configu-
rations. The underlying software algorithms are based on HPLC theory, and are very
accurate in their predictions, as summarized in Table 3.2 for a separation of cocaine,
methadone, and related substances.
The critical component in a completely automated system is software that bridges
the gap between the modeling software and CDS software that runs the system
and generates data. In these systems, the process of method development starts
with the help of a Windows-based interface between the modeling software (e.g.,
AutoChrom, LCD Labs) and the CDS. The software interface asks for specific infor-
mation about separation needs, and using software protocols, suggests actual start-
ing conditions, including pH, solvent, and column. The software can also facilitate
the setup of the method in the CDS and complete the analysis. Systems and soft-
ware are now available from many vendors that incorporate PDA and MS for peak
