How much do you know about polarimeter considerations?

How much do you know about polarimeter considerations? Polarimeter is an instrument for measuring the optical rotation of optically active substances
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By measuring the optical rotation of the sample, the concentration, content and purity of the substance can be determined by analysis
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So, do you know what to pay attention to when using a polarimeter? The following editors have compiled the corresponding matters for you, hoping to help you
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Polarimeter Notes 1.
Before the measurement, the polarimeter and the sample should be placed in a constant temperature room with a temperature of 20℃±0.
5℃ or a constant temperature room with a specified temperature.
A constant temperature water bath can also be used to keep the sample room or sample test tube at a constant temperature for more than 1 hour, especially for some optical rotations that have a great influence on temperature.
Sexual substances are especially important
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2.
Before turning on the power, check whether there are foreign objects in the sample room, whether the sodium light source switch is in the specified position, whether the indicator switch is in the off position, and whether the instrument is placed in a suitable position.
After the sodium light lamp is turned on, the instrument should not be moved.

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3.
After the sodium lamp is turned on, the normal glow time is at least 20min, and the light can be stable.
During the measurement, the sodium lamp should use DC power supply as much as possible to make the light stable
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If there is a polarity switch, the polarity should be changed frequently after shutdown to prolong the service life of the sodium lamp
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　　4.
Before the measurement, when the polarimeter is set to zero, repeatedly press the re-measure switch to make the analyzer deviate from the optical zero position to the left or right, respectively
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The repeatability and stability of the instrument can be checked by observing the stopping points of the left and right retests
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If the error exceeds the specification, the instrument should be repaired before use
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　　5.
Put the measuring tube containing distilled water or blank solvent into the sample chamber.
If there are air bubbles in the measuring tube, the bubbles should be floated on the convex neck first, and the glass at both ends of the clear surface should be wiped dry with a soft cloth
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During the measurement, the position and direction of the measuring tube should be fixed as much as possible, and the marking should be made to reduce the error of the stress of the measuring tube and the cover glass
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　　6.
When the same optically active substance is measured with different solvents or at different pH values, due to the different conditions of association, solvation and dissociation, the specific rotation changes and even the optical rotation direction, so the specified solvent is used
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　　7.
If the solution that is cloudy or contains small particles cannot be measured, the solution should be centrifuged or filtered first, and the initial filtrate should be discarded for measurement
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Some material solutions whose optical rotation changes greatly after exposure to light should be protected from light
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Some placement time has a great influence on the optical rotation, and the readings are also measured within the specified time
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　　8.
When measuring the blank zero point or measuring the stop point of the test solution, the readings should be read three times, and the average value should be taken
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For strict determination, the zero point should be calibrated with a blank solvent before each determination.
After the determination, the reagent should be used to check whether the zero point has changed.
If the zero point changes greatly, the determination should be re-measured
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　　9.
At the end of the measurement, the measurement tube should be washed and dried and put back in its original place
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The instrument should be placed in a dry place to avoid dust, and a little desiccant can be placed in the sample room to prevent moisture
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The above is the understanding of the key points to pay attention to the polarimeter.
I believe that everyone has a corresponding understanding of this after reading it.
After understanding the relevant points, it will not affect the accuracy of the test.
I hope it will be helpful to everyone
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