The Karl Fischer Moisture Analyzer is suitable for the determination of water in a variety of organic and inorganic materials. What do you need to pay attention to when using it? 1. Tests for organic and inorganic compounds 2. Because of the difference in the nature of the compounds, they can be classified into two types: those that can be directly measured and those that cannot be directly measured. Therefore, when requesting the analyst to determine the water in a certain compound, the first thing to think about belongs to that type. If the latter is used, and the direct measurement is used, a large measurement error will occur or the substrate cannot be measured. 3. If water in a compound that cannot be directly measured is to be calibrated, an appropriate method must be used to eliminate various disturbance factors and reach the intention of accurate determination. Second, sampling and sampling Before the injection, the syringe should be cleaned 5 to 7 times with the help of the test solution, and then the sample size should be determined according to the water content of the sample. Generally, the sample of 0.1 to 5 mL is sampled according to the syringe sample of Table 3. Table 3 Sample size Refer to data sample Water content (ppm) Sample size (mL) 0-102-510-1001-2100-10000.1-1>1000<0.1 From Table 3, it can be seen that the sample with large water content is small. On the contrary, the sampling amount is large, otherwise a large measurement error will occur. Pay special attention to whether there are small bubbles in the syringe during injection to prevent serious measurement errors. Third, the accuracy of the measurement <br> Determination accuracy Karl Fischer titration method to determine the range of water content of a wide range from a few ppm to 100%, the accuracy of the request is based on the water content resolution. The general request for parallel determination of the difference between the two results and the arithmetic mean should not be greater than the following values: water content (ppm) allow the difference 1-10 ± 1ppm10-50 arithmetic mean ± 10% > 50 arithmetic mean ± 5% in progress In the analysis, the arithmetic mean of the two measurements is taken as the analysis result. Magnetostrictive System Scaler Magnetostrictive System Scaler,Cavitron Type Scaler,Dentsply Type Scaler,Dental Magneto Scaler Rolence Enterprise Inc. , https://www.rolencedent.com
1. The Karl Fischer method is applicable to the determination of water content in many inorganic and organic compounds.
When doing the sampling and sampling, try to take a representative sample with uniform mixing, and observe the existence of free water at the bottom of the container. When the sample is taken with a syringe, the extraction speed should not be too fast, otherwise there may be air entering the syringe to form a bubble, which causes an injection error. If the sample and the container are found to be opaque before the analysis, or if there are fine water droplets on the wall of the bottle, it must be analyzed by ethylene glycol extraction. The specific method is as follows: adding a third sample to the pre-dried fine-mouth bottle and sealing it, and weighing it to 0.1 g on an industrial analytical balance, and then weighing 2 to 3 times the amount of ethylene glycol to sway 15 After seeding and static stratification, 0,25-1.0 mL of ethylene glycol was taken through a sample layer by a syringe, and the water content was measured, and the original water content of ethylene glycol was also measured. After the analysis is completed, the sample in the bottle is poured off, washed and dried, and weighed to 0.1 g on the balance. According to the difference between the above three weighings, the sample and the amount of ethylene glycol are obtained, and the sample can be obtained. Water content.