How to quickly detect methanol content! ! !
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We now use specific gravity to detect the content, but the accuracy is relatively poor. We hope to find a fast and accurate detection method. Our methanol concentration is around 30%.
If you have a good instrument, it is best to use an imported instrument with an automatic sampler. Give a method.: 1. Take 1ml sample, add anhydrous sodium sulfate for dehydration, then add 10ML organic solvent, preferably a solvent that can separate from methanol. 2. Prepare 15, 20, 25, 30, 35% methanol standard samples. 3. Follow the procedure in step 1 and then establish a working curve and calculate it based on the peak area.
for reference: Methanol rapid detection reagent in fake wine Methanol is a volatile (boiling point 65°C) liquid with a slight alcohol smell, which is very harmful to the human body. therefore, * * Standard regulations: The methanol content of liquor brewed with grain as raw material shall not exceed 0.04g/100mL. The methanol content of liquor brewed with substitutes such as dried potatoes shall not exceed 0.12g/100mL. Methanol content inspection is a crucial inspection item in alcohol testing. This product uses the color-changing acid method, which can quickly detect methanol. The minimum detection limit reaches 0.01g/100mL. It is suitable for the determination of methanol content in liquor samples, and can effectively monitor on-site liquors where methanol seriously exceeds the standard. Instructions for use: (1) Take a centrifuge tube (1.5mL) and insert it into the centrifuge tube rack. Use a small dropper to take 2 drops of the wine sample to be tested and add it to the centrifuge tube. ； (2) Add 3 drops of indicator A to the centrifuge tube containing the wine sample, cover with the stopper and shake well ； (3) After standing for 5 minutes, open the stopper of the centrifuge tube, add 3 drops of indicator B into it, cover the stopper and shake well until it is colorless and clear. ； (4) Open the centrifuge tube plug, add 22 drops of indicator C (indicator C contains concentrated sulfuric acid, the centrifuge tube will heat up after mixing, please pay attention to safety when operating), cover the plug (no need to shake), and place it on the centrifuge tube rack. ； (5) Observe after 2 minutes * * Please refer to the first standard color comparison plate (physical card) for preliminary interpretation of the results. ； Shake well after observation. When shaking, hold the tip of the centrifuge tube and both ends of the plug with your index finger and thumb, and gently and slowly swing the centrifuge tube horizontally and vertically. Avoid violent vibrations that may cause the liquid in the centrifuge tube to rapidly heat up and cause the centrifuge tube to burst. ； (6) Shake well and let it sit for 3 minutes to observe the * * In this case, refer to the second standard color comparison board (color block card) to interpret the results. If there is any discrepancy with the preliminary results, the color block card results shall prevail. ； (7) At the same time, use methanol negative control solution as a blank control test, that is, replace the wine sample to be tested with 2 drops of negative control solution. The remaining steps are the same as (2) to (6) above. Scope of application: Suitable for rapid detection of methanol content in various liquors. Things to note: 1. If the methanol content of liquor brewed from grain (or substitutes such as dried potatoes) exceeds 0.04g/100mL (or 0.12g/100mL), it will indicate that the liquor is unqualified and cannot be drunk. 2. Liquor that is judged to be unqualified by on-site rapid testing must be sampled and sent to the statutory quality inspection agency for further confirmation. 3. Pay attention to the consistency of the dripping wine sample, standard sample and reagent dosage, as well as the synchronization of the detection steps and detection time. 4. The detection reagent contains strong acidic substances (concentrated sulfuric acid). Necessary protective measures must be taken during operation (such as wearing protective gloves, glasses, etc.) and pay attention to safety. After testing, the mouth of each reagent bottle should be wiped clean with a clean paper towel and the cap tightly closed. Centrifuge tubes and straws can be washed and dried before use. 5. Vertical dripping must be used during the dripping process, that is, the dropper bottle should drip vertically downward, otherwise the test results may be affected. source: http://www.laiter.com.cn/prod_jcsj_jiachun01.htm This post was last edited by brucehan on 2009-2-19 12:56 ]
These two methods can be used as a reference, thank you! ! ! !