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Agilent LC Method Development Solution: overnight answers to difficult separation problems
By Michael Frank
Agilent Product Manager, Pharmaceutical Solutions
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Figure 1. The 1200 Series LC Method Development Solution is a configurable system that allows you to automate testing of up to eight columns and 15 different solvents.
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Figure 2. Thermostatted column compartments allow you to test columns of various dimensions, at various temperatures.
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Figure 3. When a herbicide formulation changed, Dow scientists screened six columns and two solvents overnight, quickly establishing the best LC conditions. (Click here to see this image larger.)
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New LC stationary phases can significantly improve chromatographic resolution by increasing selectivity, but researchers often keep their current columns rather than spending days to comprehensively screen multiple columns and solvents. To reduce the cost of such experimentation, scientists at The Dow Chemical Company are taking advantage of the Agilent 1200 Series LC Method Development Solution to perform this screening in a completely automated fashion.
Rapid method scouting with greatly reduced effort
Dow scientists used the 1200 Series LC Method Development Solution to perform method scouting for challenging separations of chemical and agricultural samples. They tried many column stationary phases, solvent gradients, and separation conditions, all using 50 mm Agilent ZORBAX Rapid Resolution High Throughput (RRHT) columns with 1.8 µm particles. The Agilent 1200 Series Rapid Resolution LC that is incorporated into the system was operated at up to 600 bar to facilitate faster runs at higher flow rates.
Analysts at Dow successfully applied the 1200 Series LC Method Development Solution to analyses of active ingredients in herbicides, as well as impurity profiling and target compound analyses. In one example, they rapidly solved a difficult separation problem when changes in a herbicide formulation led to failure of their LC separation for quantification of active compounds. To scout for improved conditions, they tested six columns and two organic solvents. Figure 3 shows that a change from a C18 to a cyano stationary phase and from acetonitrile (ACN) to methanol (MeOH) solvent provided increased selectivity between the active compounds and the aromatic solvent used in the new formulation. Dow was able to improve this separation overnight, saving days of method development time.
Better separations via cost-saving experiments
In many cases, Dow scientists found that column and solvent scouting produced significantly better separations, while requiring only a single overnight sequence with short columns with sub-2-µm-particles. Because the Agilent 1200 Series LC Method Development Solution saves them so much time and manual labor, they can now economically perform these screens whenever they need to quickly develop a new method. Their full story with additional examples and chromatograms was presented at the HPLC 2009 Conference in Dresden, Germany. For more details, download the complete poster.
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