What are the conditions for holding samples in containers
Feb 26, 2022
The material of the container shall have strong chemical stability,
It shall not react with the water sample,
The vessel wall shall not absorb or adsorb the material to be used
Before sampling chemical products, a sampling scheme must be formulated. The sampling scheme at least includes the following contents: (1) determine the range of overall materials, that is, batch size.
(2) Determine the sampling unit, i.e. bottle, barrel, box, tank or specific time interval (convective animal material). (3) Determine the number of samples, sample quantity and sampling position. (4) Specify sampling operation methods and sampling tools. (5) Specify the preparation method of the sample. (6) Specify sampling and drilling measures.
On the premise of meeting the requirements, the less the number and quantity of samples, the better.
(1) For the determination of the number of samples, general chemical products can be treated with multi unit materials. The number of sampling units for single raw materials shall be implemented according to the regulations.
(2) Determination of sample quantity, which shall meet the needs of at least 3 repeated tests; If it is necessary to reserve samples for future reference, it shall meet the needs of samples for future reference; In case of sample preparation, it shall meet the needs of sample preparation. 2.3 requirements for sample container and sample preservation [3]
(1) The sample containers shall be provided with caps, plugs or valves that meet the requirements, and must be cleaned and dried before use. The material must not have chemical reaction with the sample material and cannot have permeability. For photosensitive materials, the penetration container is strictly opaque.
(2) Requirements for sample labels. 2] After the sample is put into the container, label the container immediately. The label contents include: sample name and sample number, overall batch number and quantity, production unit, sampling position, sample quantity, sampling date, sampler, etc.
(3) Requirements for sample preservation. In the product sampling standards or sampling operation procedures, the preservation of samples (as standby samples), preservation environment, preservation time, etc. shall be specified. The withdrawal of highly toxic and dangerous samples must comply with the relevant provisions of poisons and dangerous substances in addition to the general provisions. 2.4 requirements for sampling records [4]
During sampling, the status and sampling operation of the collected materials shall be recorded, such as the name, source, number, quantity, packaging, storage environment, sampling position, number and quantity of samples, sampling date, name of sampler, etc. Sampling records should be designed into appropriate forms to facilitate regular and convenient recording. 3. Precautions for sampling [7]
(1) There are many kinds of chemical products and the sampling conditions are changeable. During sampling, the best sampling scheme and sampling technology shall be selected according to the basic principles and general regulations of sampling and the actual situation.
(2) Sampling is a highly technical work related to accuracy test. Sampling should be carried out by specially trained personnel.
(3) Before sampling, the feasibility test of the selected sampling method and device shall be carried out to master the sampling operation technology. (4) During the sampling process, the collected materials shall be prevented from environmental pollution and deterioration.
(5) The sampling personnel must be familiar with the characteristics of the collected products and the relevant knowledge and treatment methods of safe operation. (6) During sampling, measures must be taken to prevent explosion, poisoning, combustion, corrosion and other accidents.
