[Development of integrated equipment for automatic sampling and distillate collection]

Preparative chromatography plays an important separation and purification role in the pharmaceutical， chemical， and food industries. New preparative chromatography equipment that integrates automatic sampling and fraction-collecting functions was developed to improve separation efficiency and ease of use， and to meet the separation-efficiency and collection-accuracy needs of modern industry.The design concept and working principles of the device are introduced in detail. The developed equipment significantly improves the injection rate and reduces human operating errors through advanced automation technology， leading to an experimental process that is entirely more scientific and efficient. At the same time， the fraction-collection system was optimized such that it can flexibly adjust to various application requirements， thereby ensuring the highest purities and recoveries of the collected target ingredients. This innovative equipment uses a high-speed servo motor to independently drive the X-， Y-， and Z-axes of the instrument tray in order to realize high-speed sampling and collection actions at any position within the scope of the set tray， while synchronously sampling and collecting. A control circuit was used to calibrate the sampling and collection positions to ensure accuracy and that the device is compatible with a variety of sample-tray specifications to meet the preparation requirements of a wide 1-200 mL/min flow range. The developed equipment was used to separate and purify samples of stevioside and rebaudioside A， and exhibited excellent performance， including fast separation， stable output， and accurate collection. The equipment is capable of realizing synchronous sample-collection functions， thereby providing a stable and reliable separation and purification option for a wide range of industries.