KF moisture measurement issue! ! !
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When we use KF for moisture measurement, we often fail to obtain any data recently; the times when data can be obtained are few, while those when no data is recorded are many. That is, no results appear after the sample is inserted. We hope that someone who understands this issue can help discuss what might be the cause.
What kind of solution is being used? Is it a mixture, or Solution A and Solution B? Is the liquid expired? Is the electrode contaminated? It can be soaked in chromic acid or nitric acid, and the water is removed using anhydrous ethanol
Feed water in and check whether the instrument responds. Inspect the reagents used to see if they have expired. Check whether the electrode connections are good. If nothing works, then contact the supplier
Instruction Manual for WS--2A Micro Moisture Analyzer http://bbs.hcbbs.com/viewthread.php?tid=236712&highlight=%2B%B2%D4%BA%A3%D2%BB%C1%A3%C9%B0
Thank you so much to the three friends above! ! ! We’re going back to floors 1 and 2 at the same time. We’re using Solution B, which is definitely not expired. Based on what you’ve described, it’s likely that the electrodes are contaminated. This post was last edited by ddc805 on 2009-2-17 20:53]
It might be a problem with the electrodes, or it could be an issue with the Karl Fischer reagent
A small amount of pure water can be weighed and added using a micropipette for analysis. If the water content is low, for example 50 ppm, and the electrode is dirty, it may sometimes be impossible to detect anything.
After soaking the electrode in concentrated nitric acid, we were able to measure the moisture content of liquids, but we still couldn’t measure the moisture content of solid samples! ! !
0.1 microliters of pure water is introduced. If the measured value falls between 90 and 110, it indicates that there is no problem with the amount of moisture present. If the value is much lower or no reading is obtained at all, it’s necessary to first check whether the electrolyte has lost its effectiveness. If the electrolyte is fine, then there is a high possibility that the electrodes are contaminated; it’s best to investigate any faults in the electrodes or hardware, as it’s possible that no electrolytic reaction takes place once water gets in.
To measure solids? What is the solubility? For solids, isn’t the gravimetric method commonly used? Halogen moisture meter, from Mettler; I’ve heard of it but haven’t used it yet. It’s said to be good. Here is a link: http://www.mtchina.com/foremtchina/GBHtml/Category/Category-37.html. This post was last edited by thong0421 on 2009-2-26 at 13:13.]
I suggest that you separate the testing of liquids and solids, that is, buy two KF titrators. We went to the actual factory; there are two types used for testing liquids and for testing solids.
Clean the electrode, change the solution, and then increase the sampling volume. Wish you success.
If the reagents are fine, it’s most likely a problem with the instrument’s platinum electrode; try replacing the electrode. If that doesn’t work, it might be a circuit issue.
I forgot to ask: was the solvent used for the sample chosen appropriately? Also, if the moisture content is below 0.01%, do not use a volumetric Karl Fischer titrator; based on experience, it’s better to use an electrolytic Karl Fischer titrator.
If it is a solid, find a solvent to dissolve it; water may be trapped within the solid, or stirring for a longer period may be necessary. If the sample itself contains little moisture, you can use a standard sample for testing or conduct a comparative analysis.
If it is a solid, find a solvent to dissolve it; water may be trapped within the solid, or stirring for a longer period may be necessary. If the sample itself contains little moisture, you can use a standard sample for testing or conduct a comparative analysis. Or weigh a bit more sample.