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Ways to Calculate Water Content

Created By: Hyprowira | Published Date: 06 November 2019 | Last Modified: 14 March 2021

Did you know that water has its own levels? This difference in water content is caused by biochemical processes and living organisms. Therefore, determining the formula for water content can be done through several techniques. This technique can be used as needed. The difference between the content and the liquid, then the method for determining the water content is also different. More will be explained in the following description.


Drying Technique (Thermogravimetry)

The determination of the formula for the first moisture content is by means of a drying technique, or it can also be called the evaporation of water in certain materials through heating. Furthermore, weighing will be made to the constant weight. The method is a sample of 3-5 grams weighed and then put in a dry container with a known weight.

Next, the sample is dried in an oven with temperatures around 105 degrees Celsius. This drying time itself will take as long as an hour of exercise. After being heated, the container is cooled and then weighed and dried again to obtain the constant weight that has arisen. Difference in weight of starting material and dry weight is the result of the moisture content contained in the material.

Determination by Distillation Method

The second way is to use the distillation method. Usually, this method is used for ingredients that contain fat and volatile components. The procedure if using the distillation method that is by giving a solvent of about 75-100 ml in samples containing 2-5 ml of water. The solvent with water in the material will evaporate at temperatures lower than the temperature of boiling water. The steam that is formed undergoes condensation which is accommodated in a distillate reservoir flask. In a distillate holding flask, the solvent and water separate according to their specific gravity.

Determination by Chemical Formulas

The next formula for water content is to use a chemical formula. In this formula it is still distinguished again in several categories, namely the Karl Fischer titration method, the calcium carbide method, and the acetyl chloride method. In the Karl Fischer method usually often used to measure water content in certain fluids. For example honey, flour and egg products. In principle, titrate a sample using iodine solution which is soluble in methanol and pyridine.

Meanwhile, the calcium chloride method is based on the reaction between calcium carbide and water to produce acetyline gas. The measurement is by calculating the weight difference of the mixture before and after the reaction. In addition, you also need to measure the pressure of acetyline gas if the reaction is carried out in a closed room. Then, for acetyl chloride can be used in determining certain water levels. For example oil, butter, margarine, to spices which have a fairly low water content.

Determination of Water Content by Physical Methods

Finally, this water content formula can be done using physical methods. In this physical method it is still classified in several ways. Ie, with the dielectric constant for water which has a dielectric constant whose size is 80. Likewise with other substances with certain constants. For example for carbohydrates and proteins with a dielectric constant with smaller levels. For example, daja is smaller than 10, methanol 33, ethanol 24, and acetone 214. Likewise with benzene 2.3 and hexane 1.9. To determine the formula for water content using this method, the ion charge is divided by the distance between the two ions.

So, from a number of water content formulas and the determination that has been explained above, you can use it according to the needs of the liquid to be measured. It's best to ask the experts if you are still unsure about which method to use. May be useful.

The choice of water content determination method can be chosen based on the sample character so that it gets more accurate results. The Hyprowira Adhitama Laboratory provides water content analysis services for petroleum products, lubricants, and fuels based on the ASTM D6304 method standard, water content analysis for IEC 60814 transformer oil, and Karl Fischer Titrator Mettler Toledo tools and calibration services.