Hygroscopic Fluid Dispensing Using Freezing-Point Detection

The patent replaces complex chemical titration systems with a simple thermal system. Instead of using Karl Fischer titration equipment, the invention uses a temperature sensor and cooling mechanism to measure the freezing point depression of DMSO, which directly indicates water content. This substitution of mechanical/thermal methods for chemical methods reduces device complexity while maintaining measurement capability.

The patent employs inexpensive, simple components such as off-the-shelf temperature sensors, basic cooling elements, and standard microplate well structures. These replace expensive, specialized Karl Fischer titration equipment. The system uses readily available materials that can be easily replaced or disposed of, reducing both initial cost and maintenance complexity.

The patent performs preliminary cooling of the DMSO sample to its freezing point before measurement. By pre-cooling the sample and using freezing point depression as the measurement basis, the system achieves rapid water content determination without the time-consuming chemical reactions required by Karl Fischer titration. The freezing process itself provides the measurement signal.

The patent exploits the phase transition of DMSO from liquid to solid at its freezing point. By measuring the freezing point depression caused by water contamination, the system quickly determines water content. This phase transition method is inherently faster than chemical titration because it relies on a physical property change rather than a chemical reaction that must reach completion.

The patent uses feedback control to monitor the freezing process. The temperature sensor continuously measures the temperature of the DMSO sample during cooling, and the system detects the freezing point by identifying the temperature plateau or rapid temperature change. This feedback mechanism ensures accurate detection of the freezing point despite variations in cooling rate or sample conditions, maintaining measurement precision while keeping the operation simple.

The patent employs a microplate well structure that serves multiple functions: it contains the sample, provides thermal isolation, and interfaces with the temperature sensor. This multi-functional design simplifies the overall system while maintaining measurement accuracy, as the same structure that is easy to handle also contributes to precise thermal measurement.