1. OBJECTIVE
This experiment aims to extract soybean oil from crushed grains. You will investigate the functioning of a Soxhlet extractor, generally used for the pre-treatment and extraction of oils from solid samples. The practical activity is focused on the assembly and use of the equipment to promote the extraction and on the calculation of its relative yield. You will have to carry out weighings, place the sample in the appropriate compartment, assemble the equipment, process the products obtained and calculate the percentage obtained by extraction.


At the end of this experiment, you should be able to:

plan and execute unit operations in a chemistry lab;

correctly handle organic solvents using safe equipment and methodologies for the operator;

learn to operate Soxhlet extraction equipment, paying attention to details in assembly and operation;

recognize and employ solvent evaporation methods;

extract oils from different grains using a Soxhlet extractor.

2. WHERE TO USE THESE CONCEPTS?
Sample preparation and processing is a step of great importance for analysis, as even simpler samples are often unsuitable for direct analysis due to dilution or excessive concentration of target analytes or incompatibility with instrument operating procedures. In this sense, Soxhlet extraction presents itself as a solution to some of these problems. In addition to being used for pre-treatment of samples, this technique and this equipment have been widely used for the extraction of non-polar components in solid and liquid samples. Soxhlet extraction can be used to replace techniques that use large amounts of solvent and are characterized by long extraction protocols and low efficiency.


3. THE EXPERIMENT
In this experiment, oil will be obtained from previously ground soybeans (solid-liquid extraction) using the Soxhlet equipment. The practice consists of weighing the grains, placing them appropriately in the Soxhlet, removing the solvent and calculating the yield. You must be familiar with correctly assembling the equipment and using care when handling organic solvents. After completing three cycles, solvent removal will be performed using a traditional rotary evaporator. Finally, after weighing the product obtained, you can obtain the extraction yield.


4. SECURITY
In this practice, mandatory safety equipment for laboratory practices, such as gloves, long-sleeved lab coat and safety glasses, must be used. These pieces of equipment are important for working with harmful and toxic reagents, such as organic solvents, considering the risk associated with handling them. Hexane is a dangerous solvent for the operator and must be handled in a hood or under an extractor hood. After transferring the solvent into the flask, the solvent vial should be immediately closed; in case of spillage, clean up immediately. The goggles protect against splashing solvent in the eyes, while the glove and lab coat prevent the reagents from coming into contact with the skin.


5. SCENARIO
The environment in which the experiment will be conducted must be clean, with good light and air. On the bench, the starting materials, reagents, glassware, balance, Soxhlet extractor parts, test tube, a rotary evaporator and a calculator. The orders and instructions presented in the Route must be strictly followed. Solvents must not be opened on worktops, but in hoods or hoods with glass at half height. Its handling must be carried out carefully and with personal protective equipment. It is important to have a laboratory notebook and a pen in hand to take notes regarding observations during the execution of the experiment and to calculate the percentage obtained from the final product.