The laboratory spatula is an instrument that consists of a rod, usually made of stainless metal, that serves as a spoon in chemical analysis. It is the spoon that we use in the kitchen, but with some modifications that make it essential for handling reagents, such as salts, oxides, acids, bases, etc.
Laboratory spatulas are utensils that help with mixing, scraping, and other tasks related to transferring materials and samples from one place to another.
Material: Stainless Steel (410)
Includes: Double flat-ended with 3 L x 0.75 in. W
For Use With (Application): Heavier work
In the kitchen, we use a teaspoon to serve sugar, milk, cocoa, rice grains, etc. Exactly this is the function of the spatula in the laboratory: to transport solid reagents from one place to another. It is therefore very useful when weighing reagents and standards (standards), as well as in collecting a precipitate or crystals.
In the image above we can see a typical laboratory spatula. Note that it has two ends: one flat and the other curved.
The round end, as it has a concave surface, is often preferred when it is necessary to collect a granular or powdered solid from their respective containers. Meanwhile, the straight end, although it also serves the former, is usually reserved mostly to scrape the internal walls of a beaker, or to accommodate the filter paper during filtration or vacuum drying of the crystals.
Characteristics of laboratory spatulas
Of the laboratory materials, the spatula is one of those with the most different shapes and characteristics. That is, in the same laboratory we can find several types of spatulas. Due to this, some general characteristics will be mentioned, and other specific ones, in relation to spatulas used in a laboratory:
-They are relatively cheap (compared to glass materials).
-Many spatulas are made of materials such as stainless steel or nickel, featuring a polyvinyl chloride plastic handle, or a wooden handle that is quite reminiscent of knives and spoons.
-The material with which they are made must not be absorbent. That is why the famous popsicles can never be used in a laboratory, as they would absorb reagents and could not be washed or reused.
-The laboratory spatula must be inert and resistant to high temperatures and organic solvents.
-There are spatulas made from porcelain, with which dusty solids are taken.
-Other spatulas, on the other hand, are made of various types of plastics, such as polyamide, nylon, polypropylene, polytetrafluoroethylene, etc., each with very specific uses.
-Depending on its material, the spatula can be disposable, especially when trying to avoid contamination between different solids.
The spatula is mainly used for handling solids and, as we do with a teaspoon when dissolving sugar in a cup, shaking liquids to ensure complete dissolution of a solute. Thus, its functions are as follows:
The spatula has a flat or curved surface on which the solid to be handled or transported from one place to another can rest. In this sense, its function is the same as that of a normal spoon.
Although it is normal to use a glass rod for this purpose, the spatula also allows you to stir solutions of the same reagent that you recently handled. Usually this is only done for small, qualitative solutions. When they are large (500 mL or more), it is chosen to use a magnetic stirrer.
Many times in precipitation reactions, sediments form at the bottom and on the inner walls of the beaker or beaker. This is when the spatula is very useful, since its hard edge perfectly scrapes the remaining solid, thus contributing to its recovery and a better performance of the reaction in general.
Remove filter papers from funnels
Another of the most important functions of the spatula is that it facilitates the removal of filter papers in the filter funnels. If it were not for the spatula, this process would be complicated and would also run the risk of contaminating the precipitate or the crystals obtained.
Note in the image above that the thinner end of the spatula is used for this process, as you must carefully lift the edge of the filter paper with the sample on its surface.
Uses / applications
The functions mentioned in the previous section alone offer many of the uses that a laboratory spatula normally has. However, some very specific ones that are based on the functions above will be cited here, and finally.
The spatula is ideal for handling solids by hand, making it the instrument of choice for weighing solids on the analytical balance. The process consists of sinking the spatula into the solid content of the container and hitting it with the index finger so that it is not overflowing and weighing is more comfortable.
The curved end (scoop type) is generally used for this purpose. However, there are very small containers where it is necessary to insert the flat end (knife type). Thus, the thin, flat end is used for weighing standards, where amounts are usually only a few milligrams (less than 100 mg).
Heavy sodium hydroxide
Unless the spatula is completely inert to alkalis, sodium hydroxide pellets should not be weighed with a metal spatula. Instead, plastic spatulas, resistant to the base, are used.
Collect solids from test tubes and centrifuge
Very fine-tipped spatulas are ideal for collecting solid samples from test tubes or centrifuge tubes, with which further analysis can be carried out.
Remove or apply solids
Spatulas are also very useful for, for example, removing a paste-like product from a reaction balloon, such as a resin. Likewise, it facilitates the handling of dusty solids and their application on different sample holders.
This use was already mentioned above. However, it should be noted that a glass rod, with a plastic end that is known as a police rubber, works perfectly as a spatula to scrape and recover solids from the internal walls of a beaker, flask, balloon, etc.