Use of DryLab programs as the core of a systematic method development strategy.

Requirements for new pharmaceutical products and their impact on applications of high-performance liquid chromatography (HPLC) are discussed. The strengths and weaknesses of HPLC in this context are evaluated and compared with current trends and expectation in separation science.

Computer-aided method development techiques have been commercially available for a number of years. Each of these procedures has strengths and weaknesses. In the past, hidden difficulties in the practical application of computeraided method development have discouraged their widespread use. This paper proposes the complementary use of these techniques so that their strengths are maximized while their weaknesses are compensated for. The result is a method development strategy that obtains simple solutions for simple separation problems and reserves the more complex solutions for difficult separations.

Isocratic method for the separation of nitrobenzene, 2,6-dinitrotoluene, benzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, 2-nitro-1,3-xylene, 4-nitro-1,2-xylene. The most robust Separation is available at (60:40)(MeOH:Water) on a 250x4.6mm, 5 µm C18 column at 2 ml/min flowrate.

Summary

The ribosomal 50S and 30S subunit proteins (r-proteins) of Thermus aquaticus have, for the first time, been characterized by size exclusion chromatography (SEC) and by reversed phase high performance liquid chromatography (RPC). To ensure that the best resolution in the RPC was obtained. the elution conditions, such as gradient time, flow rate, temperature, ionic strength of the eluent and the type of stationary phase were optimized. Correlation between experimentally found retention times and those predicted by DryLab G was better than 0.7% over 30 peaks. Protein fractions from RPC runs were desalted and processed by gel electrophoresis so that the ribosomal proteins could be identified by their position on SDS-polyacrylamide gels. The enhanced speed and quality of separation which has been achieved in this study is expected to bring advantages in experimental work with ribosomal proteins as well as with other biopolymers. In our case the high resolution technique provides a basis for the preparation of a collection of individual ribosomal protein components for future rRNA-protein interaction studies.