Analysis method of medium and short chain inulin based on acid hydrolysis

[0038] Example 1:

[0039] A method for analyzing short- and medium-chain inulin based on acid hydrolysis, including the following steps:

[0040] 1. Preparation of fructose standard solution: configure fructose standard (purity 99%) into a gradient solution of 0.20-0.60 mg / mL to be tested. Draw a standard curve with the concentration of fructose as the abscissa and the peak area of ​​the liquid phase as the ordinate.

[0041] 2. Acid hydrolysis of inulin: Weigh 4.5 mg of short- and medium-chain inulin extract into an ampoule, add 3 mL of trifluoroacetic acid TFA with a concentration of 1 mol / L, seal it with a blowtorch, and react at 90°C for 60 minutes to hydrolyze the sample complete.

[0042] 3. Deacidification of the hydrolyzed solution: transfer the hydrolyzed sample solution to a micro-rotating flask, add 20 mL of methanol, and rotate it for 20 minutes at 40°C and a speed of 250r / min to remove the residual trifluoroacetic acid in the hydrolysate. After the solution is evapo

[0044] Example 2:

[0045] A method for analyzing short- and medium-chain inulin based on acid hydrolysis, including the following steps:

[0046] 1. Preparation of fructose standard solution: same as Example 1.

[0047] 2. Acid hydrolysis of inulin: Weigh 4.5 mg of short- and medium-chain inulin extract into an ampoule, add 3 mL of trifluoroacetic acid TFA with a concentration of 0.5 mol / L, seal with a blowtorch, and react at 90°C for 60 minutes to make the sample The hydrolysis is complete.

[0048] 3. Deacidification of the hydrolyzed solution: transfer the hydrolyzed sample solution to a micro-rotating flask, add 15 mL of methanol, and spin-evaporate for 10 minutes at 40°C and a rotation speed of 200r / min to remove the residual trifluoroacetic acid in the hydrolysate. After the solution is evaporated to dryness, add 10mL of water to reconstitute it, and store at 4℃;

[0049] 4. HPLC-ELSD detection: same as Example 1.

[0050] Example 3:

[0051] A method for analyzing short- and medium-chain inulin based on acid hydrolysis, including the following steps:

[0052] 1. Preparation of fructose standard solution: same as Example 1.

[0053] 2. Acid hydrolysis of inulin: Weigh 4.5 mg of short- and medium-chain inulin extract into an ampoule, add 3 mL of trifluoroacetic acid TFA with a concentration of 1.5 mol / L, seal with a blowtorch, and react at 90°C for 60 minutes to make the sample The hydrolysis is complete.

[0054] 3. Deacidification of the hydrolyzed solution: transfer the hydrolyzed sample solution to a micro-rotating flask, add 30 mL of methanol, and rotate it for 30 minutes at 40°C and a speed of 300r / min to remove the residual trifluoroacetic acid in the hydrolysate. After the solution is evaporated to dryness, add 10mL of water to reconstitute it, and store at 4℃;

[0055] 4. HPLC-ELSD detection: same as Example 1.