The absorbance detection experiment and evaluation of commonly used HPLC grade chromatographic solvent products have been completed. The experimental results indicate that, Sigma-Aldrich ® The brand chromatographic mobile phase solvent meets the requirements of the absorbance detection index added in the 2025 edition of the Chinese Pharmacopoeia.
In chemical laboratories, bottle mouth separators are the core tool for improving separation efficiency and ensuring operational safety. They can make the transfer of high-risk reagents such as strong acids and bases safer, more accurate, and more convenient.
Various common laboratory procedures require the use of sterile containers. However, if you are using laboratory plastic products, there are several issues that must be considered before placing the container in the autoclave. Here are six questions to ask yourself before high-pressure sterilization of plastic bottles to ensure that the process is carried out in a safe and effective manner.
Although some plastic polymers are suitable for high-pressure sterilization, there are also some that are not suitable. For example, you should not high-pressure sterilize plastic bottles made of low-density polyethylene (LDPE) or high-density polyethylene (HDPE). The temperature range of these polymers is very narrow, with LDPE ranging from -50 to+80 ° C, while HDPE has a wider temperature range of 100 to+120 ° C, but still lower than the most commonly used 121 ° C for high-pressure sterilization. Other polymers that are not suitable for high-pressure sterilization include polymethyl methacrylate, acrylic acid (PMMA), polystyrene (PS), and polyvinyl chloride (PVC), also due to their narrow temperature range.
Various laboratory processes require plastic containers, but understanding the chemical compatibility of plastics - their physical properties - and how this affects the compatibility of chemicals in contact with plastic containers is crucial.
In this lesson, we have listed the most common types of plastic containers in laboratory environments, summarized the main characteristics of each type of plastic container, and provided suggestions on the most suitable and unsuitable substances to ensure that laboratory containers have correct plastic chemical compatibility.
When the ultrasonic cleaning machine is working, I believe many people are not very familiar with which factors affect the washing effect. Now let's talk about one of the influencing factors - temperature. The most suitable cleaning temperature for the cleaning solution of the cleaning machine is 50-65 degrees. If the temperature of the ultrasonic cleaning solution is low and the cavitation effect is poor in cold weather, the cleaning effect of the ultrasonic cleaning machine will also be poor. Therefore, it is necessary to wrap a heating wire around the outside of the cleaning tank of the ultrasonic cleaning machine for temperature control.
Usually, heating can provide cleaning speed, and the chemical components in most cleaning solutions will achieve the best cleaning effect at a certain temperature. The best way to know the optimal cleaning temperature is through experimentation. The optimal temperature for ultrasonic cleaning is usually between 50-65 degrees Celsius.
When the temperature rises, cavitation is prone to occur, and ultrasonic cleaning machines have the best cleaning effect. As the temperature continues to rise, the gas pressure inside the bubble increases, causing a decrease in sound pressure and weakening the cleaning effect. The cleaning solution of ultrasonic cleaning machine needs to be cleaned at a temperature close to the boiling point. So, when using an ultrasonic cleaning machine for cleaning, we should pay attention to its temperature and not ignore the impact of temperature on it, in order to ensure the best cleaning effect of the cleaning machine.