Laboratory glassware is an indispensable tool for chemical analysis work, and it is a consumable item commonly used in laboratories and is not valued by people. In normal work, its expenditure is second only to medicines. Reasonable management and use of glassware not only can effectively ensure normal work, but also reduce losses and save money.
(1) Characteristics and types of glassware.
In general, most of the chemical laboratories use glassware, and only a small number of experiments use plastic utensils in order to reduce the interference of the experiment. The glassware used in the chemical experiment has a small coefficient of thermal expansion due to its composition, is resistant to quenching and rapid heat, and has relatively high thermal stability and chemical stability.
Chemical glassware has a higher melting temperature than plastic vessels. Laboratory glassware commonly used in daily work includes scale tubes, pipettes, measuring cylinders, burettes, volumetric flasks, thermometers, test tubes, flasks, beakers, conical flasks, laboratory funnels, droppers, glass rods, plastic dropper, and the like.
(2) Classification management of glassware.
As the company continues to expand and the equipment is constantly updated, the number of glassware required is not only greatly increased, but also the variety is increasing. According to the previous methods of use and management, there are bound to be many drawbacks. Therefore, in the call for cost reduction and efficiency increase, we should start from ourselves and start with the details.
In view of the diversity and vulnerability of glassware, the laboratory must reserve a sufficient amount of goods. The previously unregulated and unrecorded management forms are obviously lagging behind, often causing repeated purchases, increased inventory, and increased difficulty in finding difficulties. If we adopt different types and different specifications for classification, we will make a detailed schedule when paying, so that the goods can be cleared, saving money, saving space and saving time. Can better put energy into the work. Glassware is very fragile and should be handled with care to avoid unnecessary waste due to negligence.
(3) Storage of glassware.
For glass instruments stored in warehouses, the infrequently used ones are sorted according to requirements, and the frequently used ones should be placed on a stable test bench or in a laboratory cabinet. Different vessels have different placement requirements. For example, after cleaning the conical flask, it should be placed regularly in the sampling basket or on the experimental table. It should not be placed at random to prevent damage. After the burette is used, the internal night must be washed. To prevent dust from entering, you can cover the plastic sleeve or invert it on the titration tube holder. For the long-term unused burette to be cleaned, the Vaseline backing paper is separated, and the piston is stored with a rubber band to prevent sticking or slipping damage. After the pipette is used, it is washed and placed on the pipe rack or placed in a dustproof box for use. After washing the cuvette, place the filter paper in a clean porcelain dish, place it on the filter paper or put it in a clean container. For instrument vessels with a grinding plug, such as a volumetric flask, the stopper and the bottle mouth should be fastened with rubber bands or wires before use to avoid accidentally breaking or mixing the plug. For long-term use, it is necessary to pad a piece of paper between the bottle mouth and the stopper when storing, so as not to stick to the time for too long.
(4) Clean storage of glassware.
Put the stored utensils on the premise of being clean, tidy and convenient, and put labels on different storage points, indicating the name, specifications and time, so that the placement is conspicuous and convenient to use.
In normal working use, if used glassware and plastic utensils are not cleaned or contaminated, it will directly affect the accuracy of the test results, resulting in large errors and even failure of the test. Therefore, it is important to ensure the cleanliness of the glassware. For those that have not been used, they should be cleaned and dried in strict accordance with the regulations, otherwise they will introduce errors and lose reliability. At the same time, try to be dedicated to the special dish. For easy-to-clean reagent residues, the relative error of re-use after cleaning is small, but for reagents that are difficult to clean, even if they are used in other tests after cleaning, the probability of cross-contamination will increase. Therefore, the correct label is the premise to ensure the accuracy of the sample results.
(5) Drying of glassware.
According to the requirements of practice at work, some utensils such as beakers and conical flasks can be used at the time of washing, and some chemical experiments require that the analytical instruments should be dry. Some require no water, and some require no trace. The requirements vary from project to project. Therefore, according to different requirements, it should be washed and dried after each use. For those who are not in a hurry, dry naturally. After washing with pure water, invert it in a clean place to control the moisture, so as to achieve the purpose of natural drying. For continuous use of the instrument, after washing and controlling the moisture, put it into an electric oven for drying, the oven temperature is 105—120 0c for about 1 hour, or it can be dried in a dry box. Some weighing bottles for weighing are cooled and stored in a desiccator after drying until completely dry. Therefore, professional staff should do different pre-test work according to different experimental requirements, experimental environment, and experimental utensils.
