1, the laboratory chemical reagent collection
(1) chemical reagent collection should be based on the experimental notification form, the laboratory administrator to prepare the required chemical reagents. General chemical reagents, by the subject teacher for registration procedures, before receiving. Dangerous drugs, precious metal chemical reagents, to meet the principle of experimental teaching, by the application of the subject teacher, approved by the supervisor, before receiving.
(2) each time the number of chemical reagents, the laboratory administrator should be weighed, recorded in a timely manner in the container on the gross weight label, for the purpose of accounting vouchers.
(3) When receiving chemical reagents or drugs, you should confirm that the name on the container is the name of the drug you need for the experiment. Pay attention to drug hazard labels and drawings for hazards. For your safety and the smooth running of the experiment, check the drug report form (if available) and the MSDS of the reagent or drug.
(4) The use of flammable and explosive, toxic, corrosive, oxidizing and other dangerous reagents must be applied for in advance to report, so that the number of how much to use how much to receive, and a preparation into the use of reagents. Toxins issued in accordance with the principle of first-in-first-out, issued with accurate registration (reagent measurement, issuance time and the person in charge). All poisonous substances must be two people to receive, two people to return, otherwise the custodian of the poison warehouse has the right not to issue.
2 laboratory chemical reagents custody
2.1 chemical reagents should be stored depending on their nature
General reagents can be stored in glass bottles; glass has a strong corrosive effect of reagents, such as hydrofluoric acid, sodium hydroxide should be stored in polyethylene plastic bottles; easily oxidized by the air, differentiation, deliquescence of reagents should be sealed and preserved; easy to decompose the reagent should be colored Glass bottle storage and hidden in the dark; susceptible to thermal decomposition and low boiling point solvents, should be stored in a cold place; highly toxic reagents should be stored in the safe; radioactive reagents should be stored in lead canisters.
2.2 Do a good job of regular maintenance of chemical reagents
If the chemical reagents are not properly stored, they will fail and deteriorate, affecting the effect of experiments, and cause waste of materials, and even sometimes accidents. Therefore, the scientific storage of good reagents to ensure the smooth progress of the experiment, to obtain reliable experimental data has a very important significance. The deterioration of chemical reagents, most of the cases are due to the influence of external conditions, such as oxygen in the air, carbon dioxide, water vapor, acidic and alkaline substances in the air, as well as the ambient temperature, light, etc., can make the chemical reagents oxidation, reduction, deliquescence, weathering, precipitation of crystals, dilution, corrosion, decomposition, volatilization, sublimation, polymerization, mildew, discoloration, and ignition of the explosion and other changes. Often check the storage of chemical reagents in storage conditions found that the actual storage period or deterioration should be reported in a timely manner, and in accordance with the provisions of the proper handling (degradation of use or scrap) and write-off. Under normal storage conditions, general chemical reagents should not be stored for more than 2 years, the benchmark reagent not more than 1 year.
In order to avoid interference with the environment and other factors, all chemical reagents once taken out shall not be put back into storage containers: belonging to the reagents must be recycled or designated, the reagents returned to the warehouse, you must set up a separate special container recycling or storage, with a moisture-absorbent or oxidizable, easy to deterioration of chemical reagents must be sealed and stored, to avoid hygroscopic solution, oxidation or deterioration. Regular inventory, check the error should be checked in a timely manner, and reported to the competent leadership or departmental processing.
3 laboratory chemical reagent storage
Chemical reagents should be stored in reagent bottles, tightly plugged caps, placed firmly on the cabinet shelves to ensure safety. And placement should be arranged in a neat and orderly, and easy to access. All chemical reagents should be labeled with the name of the reagent solution, concentration and preparation time. The size of the label should be appropriate to the size of the reagent bottle, the handwriting should be clear, the font should be correctly written, and it should be stuck in the middle of the bottle slightly above the center of the bottle to make it neat and beautiful, and the label can be coated with molten paraffin to protect it. Special attention should be paid to the safety of chemical reagents. The place where the reagents are kept should be cool, dry and well ventilated. Since there are various kinds of reagents, general reagents are classified into two categories: inorganic and organic, and special reagents and dangerous reagents are stored separately.
3.1 Inorganic chemical reagents storage
Salt, monomers, oxides, bases, acids and other categories are stored separately. Salts generally according to the position of the metal ion in the periodic table, also from left to right, first under the salt after the acid salt method of classification: such as sodium salt - sodium sulfide, sodium carbonate, sodium silicate, sodium nitrite, sodium sulfate, sodium sulfate, sodium thiosulfate, calcium salts and so on. Monomers are further divided into metals and nonmetals or classified by the group of the monomer element in the periodic table. Oxides are also classified according to the order of the groups in the periodic table. Non-oxygenated acids can be categorized according to the group of the root element in the periodic table from left to right, from top to bottom: such as hydrohalic acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydriodic acid, etc. Oxygenated acids can be categorized according to the group of the root element in the periodic table from left to right, from top to bottom. Oxygen-containing acids can be categorized according to the grouping of the acid-forming elements: boric acid, nitric acid, sulfuric acid, phosphoric acid, etc. Alkalis mainly according to the alkali can be in the metal elements in the periodic table of the family classification: such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, etc..
3.2 organic chemical reagents storage
Functional group classification: such as hydrocarbons (saturated hydrocarbons, unsaturated hydrocarbons), hydrocarbon derivatives (alcohols, aldehydes, ketones, acids, ethers, esters), carbohydrates, nitrogen-containing compounds, organic molecules away from the compounds and so on. Each reagent should be arranged in order of purity level, the prepared solution should be stored separately from the solid reagents.
3.3 special attention: the storage of hazardous chemical reagents
Hazardous chemical reagents with high chemical activity of substances, such as flammable and explosive reagents, corrosive reagents, toxic reagents, oxidizing reagents, radioactive and other harmful to people and the environment, a series of "potent" chemical substances, the "activity" of its The "activity" is so high that it can even decompose itself and threaten the safety of life and property, so it must be taken seriously. According to the relevant provisions of the state, the packaging of hazardous chemical reagents are marked with a hazardous symbol, hazardous code number, in the relevant reagent manuals also have the text description.
(1) flammable and explosive chemical reagents must be stored in a dedicated hazardous reagent warehouse, and stored in non-combustible materials made of cabinets, shelves, the temperature should not exceed 28 ℃, according to the provisions of the implementation of the "five double" system. A small number of bottles can be set up in the laboratory dangerous goods cabinet, according to the nature of the compartment storage, the same compartment shall not be mixed with oxidizers and other nature of the conflict with the goods, and according to the type of storage equipped with the appropriate fire extinguishing equipment and automatic alarm devices. Low-boiling point highly inflammable reagents should be stored at low temperatures (below 5 ℃, prohibit the use of sparks generated by the ordinary household refrigerator storage).
(2) oxidizing reagents shall not be stored with other reagents of conflicting nature **** together. Packaging should be intact, sealed, forbidden to mix with acids, should be placed in a cool, ventilated place, prevent sun exposure.
(3) corrosive reagent storage containers must be reasonably selected according to the different corrosive, acids should be cyanide, foaming agents, water combustion products, oxidizers, etc. away from the alkali should not be mixed.
(4) highly toxic reagents should be away from open flames, heat, oxidizers, acids and food storage in a well-ventilated place, generally not with other types of *** with the storage, and should be implemented in accordance with the provisions of the "five double" system.
(5) chemical reagents in water flammable reagents must be stored in a dry, strictly leak-proof and storms or tidal floods to ensure that water does not enter the warehouse during the period. Not in the hydrochloric acid, nitric acid and other items emitting acid mist stored together, and not mixed with other dangerous goods.
In addition to the above three categories, there are other categories: such as indicator, according to the acid-base indicator reagent, redox indicator, other indicators, coloring agents, etc., classified storage; cleaning agent and acidic chemical wash, alkaline chemical wash, other chemical wash and general cleaning agent.
4 precautions for the safe use of chemical reagents
Take out the agent can not be poured back into the original reagent bottles, take out the agent should be covered, do not put, so as to avoid Zhang Guan Li. For safety reasons, before the use of chemical reagents, first of all, its safety features - whether flammable and explosive, whether corrosive, whether toxic, whether strong oxidizing and so on, to have a comprehensive understanding. In order to take some safety precautions in the use of targeted, so as to avoid improper use of laboratory personnel and experimental equipment caused by the hazards. The following classification of chemical reagents from the safety performance of the various types of chemical reagents in the use of precautions were introduced.
4.1 flammable and explosive chemical reagents
Generally, the flash point of 25 ℃ below the chemical reagents are included in the flammable chemical reagents, which are mostly volatile liquids, can be combusted in the presence of open flame. The lower the flash point, the easier it is to burn. Flammable chemical reagents should never be used with open flames, and should not be heated directly with a heater, generally without a water bath. In the use of flammable chemical reagents in the laboratory personnel, to wear the necessary protective gear, it is best to wear protective glasses.
4.2 Toxic chemical reagents
General chemical reagents are toxic to humans, in the use of a large number of inhalation must be avoided; after the use of public performance reagents, to wash hands in a timely manner, wash your face and take a bath, change the overalls, for some inhalation or ingestion of a small amount of chemical reagents can be poisoned to death, such as: potassium cyanide, sodium cyanide and its cyanide; arsenic trioxide and some arsenic compounds, mercury chloride and some mercury salts, mercury sulfide, mercury sulfate, mercury sulfate, mercury sulfate, mercury sulfate, mercury sulfate and mercury sulfate salts. Mercury chloride and some mercury salts, sulfuric acid, dimethyl ester and so on. In the use of these reagents must understand the first aid treatment of poisoning, highly toxic reagents must have a special person to keep, strict control of the amount of use.
4.3 Corrosive chemical reagents
Any chemical reagent touching the skin, mucous membranes, eyes, respiratory organs should be cleaned up in time, especially for the skin, mucous membranes, eyes, respiratory organs have a strong corrosive chemical reagents, such as: a variety of acids and bases, phosphorus trichloride, bromine, phenol, water hydrazine, etc., in the use of the corrosive reagents before you must know the first aid treatment of these contacts. Before use, be sure to know the first aid treatment for contact with these corrosive chemicals. Such as: acid splash on the skin to wash with lye and so on.
4.4 strong oxidizing chemical reagents
Strong oxidizing chemical reagents are peroxide is containing strong oxidizing ability of oxygen-containing acids and their salts. Such as: hydrogen peroxide, potassium nitrate, perchloric acid and its salts, potassium permanganate and its salts peroxide benzoic acid, phosphorus pentoxide and so on. And then under appropriate conditions can release oxygen explosion, and with organic materials, aluminum, zinc powder sulfur and other flammable substances to form explosive mixtures, in the use of the ambient temperature is not higher than 30 ° C, ventilation should be good, and do not use with organic or reducing substances **** with (heating).
4.5 flammable reagents in contact with water
These chemical reagents are potassium, sodium, lithium, calcium, calcium, calcium carbide, etc., in contact with water can be a violent reaction, and release a lot of heat, but also can be combustible, in the use of the water should be avoided to avoid direct contact with water, and do not contact with the human body, so as to avoid burns to the skin.
4.6 radioactive chemical reagents
The use of such chemical reagents, must be used in accordance with the use of radioactive substances, to take protective measures. Other types of dangerous chemical reagents, whether commonly used or not, before use must understand its safety precautions before use.
In the process of chemical experiments due to improper operation or carelessness will inevitably lead to accidents. The problem is that when an accident occurs to have the right attitude, calm mind, do not panic, two to timely and correct handling, three according to the requirements of standardized operation, try to avoid accidents. For example, when diluting concentrated sulfuric acid, the sulfuric acid should be injected into the water slowly along the inner wall of the container, stirring while adding to make the heat spread evenly. When doing experiments with toxic gases, try to do them in a fume hood. If you accidentally get phenol on your hands, you should immediately scrub them with alcohol and then rinse them with water.
In short, the management of chemical reagents must require managers to have professional knowledge of chemical reagent management. Including commonly used reagents, properties, uses, general safety requirements, first aid measures, the disposal of end-of-life reagents and fire knowledge. Strict management of chemical reagents to ensure the smooth progress of the experiment, which is an important part of laboratory safety.