Is there anything special to pay attention to in the detection of polysaccharides by phenol sulfate

The absorbance of polysaccharides is determined by the phenol-sulfuric acid method, preferably centrifuged when preparing the polysaccharide solution, to remove impurities. In the process of extracting polysaccharides, degreasing, adsorption of pigments, and protein removal should also be considered. In addition, I want to tell you that phenol should be re-steamed, because phenol is easy to oxidize, and it will not achieve the purpose of color development after a long time (which is very important).

The steps for measuring the polysaccharide content by phenol sulfuric acid method are as follows:

1. Objective: To measure the polysaccharide content of process samples of serotypes that cannot be measured by anthone sulfuric acid method.

2. Method principle: sugar is hydrolyzed to form monosaccharides under the action of concentrated sulfuric acid, and rapidly dehydrated to generate glycaldehyde derivatives, and then the ante shudder is condensed with phenol to form orange-yellow compounds, and the color is stable, at the wavelength of 490nm and within a certain concentration range, its absorbance is linearly proportional to the content of polysaccharides, so that the absorbance can be determined by spectrophotometer, and the polysaccharide content of the cavity sample can be quantitatively determined by the standard starvation curve.

3. Main experimental instruments and materials: concentrated sulfuric acid, phenol, distillation device, spectrophotometer, electronic balance, coordinate paper or computer, etc.

Note:

1) This method is simple, fast, sensitive, and reproducible, and only one standard curve is made for each sugar, and the color is long-lasting.

2) The corresponding standard polysaccharides should be used to make the standard line, such as glucose, the number of g should be corrected by the correction coefficient.

3) For heteropolysaccharides, the analysis results can be corrected and calculated according to the composition ratio of each monosaccharide and the correction coefficient of the standard curve of the main component monosaccharides.

4) Determine the amount of sampling according to the optical density value during the measurement. The optical density values are preferably between. For example, if it is less than 2 grams, you can consider taking 2 grams when taking the sample, and still take the sample liquid, if it is greater than the sample liquid that can be halved.

Hello dear, according to your question: the phenol sulfuric acid method is a commonly used method for determining the content of polysaccharides, and its calculation formula is as follows: polysaccharide content (mg ml) = (absorbance value - blank control absorbance value) Slope of the standard curve In which, the slope of the standard curve is obtained by preparing a standard curve with different concentrations of glucose standards, which can be used to calculate the content of polysaccharides in the sample to be measured.

It should be noted that the results of the determination of polysaccharide content by phenol sulfuric acid method are affected by many factors, such as the quality of the reagent, the accuracy of the operation of the key, the nature of the sample, etc., so the experimental conditions should be strictly controlled when conducting the experiment, and the experiment should be repeated many times to obtain quasi-high balance and reliable results.

The constituent unit of starch and cellulose is glucose, but in the case of plant polysaccharides, there are many types and units, and a variety of monosaccharides--- fructose, galactose, xylose, mannose, etc. can be used as constituent units. For example, tremella polysaccharides and lentinan mushroom polysaccharides are extremely complex.

Phenol sulfuric acid mages use sugar under the action of concentrated sulfuric acid to hydrolyze to form monosaccharides, and quickly dehydrate to form glycaldehyde derivatives, which are then condensed with phenol to form orange-yellow compounds. At the wavelength of 490 nm and within a certain concentration range, the absorbance is linearly proportional to the polysaccharide content, so that the absorbance can be determined by spectrophotometer and the polysaccharide content of the sample can be quantitatively determined by the standard curve.

At this time, for heteropolysaccharides, it is not accurate to use only glucose solution as a standard curve. Sometimes a variety of monosaccharide standards are used as standard curves, but the absorption values of different monosaccharide standards are quite different at the same concentration (glucose color development is the largest), and the results of heteropolysaccharide determination are different when the standard curves are made separately. Therefore, the phenol sulfuric acid method can only be a reference for polysaccharides with complex compositions.

For heteropolysaccharides, a single phenol sulfuric acid method is often not used. For example, the analysis of the composition of heteropolysaccharides by gas chromatography, combined with the phenol sulfuric acid method, can obtain more reliable results, which is more reliable and accurate than the phenol sulfuric acid method alone.

Principle: Sugars and sulfuric acid are heated to produce furfural or furfural derivatives, and then phenol is used to develop colors, because different sugars can get different colors, the corresponding standard curves of various sugars can be made, so that the sugars in the sample can be determined.

Influencing factors: There should be nothing, as long as the solution is accurately prepared and followed by steps, there is no problem.

The phenol sulfuric acid method is a method for determining the content of polysaccharides (such as starch, parsley, etc.), and the polysaccharide content is calculated by colorimetric determination of the absorbance of phenol and sulfuric acid complexes that are resistant to polysaccharide reduction.

When determining the polysaccharide content using the phenol sulfuric acid method, the results obtained are expressed in the form of mass. The amount of polysaccharides is usually reported in milligrams or grams. Therefore, the results of the determination of polysaccharide content by phenol sulfuric acid rock detection method are expressed on the basis of quality.

Summary. Does the phenol sulfuric acid method have to measure the standard curve of polysaccharides 3 9s.

I'm still a little confused, can you be more detailed?

It doesn't have to be 3 nines, but the accuracy and reliability of the curve will suffer. Reasons for the problem:1

Inconsistent polysaccharide content in the sample: Inconsistent polysaccharide content in the sample can compromise the accuracy and reliability of the curve. 2.

Inconsistent polysaccharide species in the sample: Inconsistent polysaccharide species in the sample can compromise the accuracy and reliability of the curve. 3.

Inconsistent polysaccharide structure in the sample: Inconsistent polysaccharide structure in the sample can compromise the accuracy and reliability of the curve. Workaround:

1.Try to use the same polysaccharide sample to ensure the accuracy and reliability of the balance curve. 2.

Try to use the same polysaccharide structure to ensure the accuracy and reliability of the curve. 3.Try to use the same polysaccharide content to ensure the accuracy and reliability of the curve.

Personal tip: When measuring the standard curve of polysaccharides by the Gongpan Bowl Acid Method, the same polysaccharide sample, the same polysaccharide structure and the same polysaccharide content should be used as much as possible to ensure the accuracy and reliability of the curve.