Detection method of L-malic acid

Abstract

The invention relates to the technical field of analysis and detection, in particular to a detection method of L-malic acid. The detection method of L-malic acid provided by the invention comprises the following steps: diluting a sample with a diluent, and then carrying out HPLC (High Performance Liquid Chromatography) detection, the diluent is composed of water; chromatographic conditions of the HPLC detection are as follows: a chromatographic column is a C8 reversed-phase chromatographic column; a mobile phase is composed of phosphoric acid, water and methanol, and isocratic elution is carried out. When the method provided by the invention is used for detection, the dosage of the L-malic acid in the reference preparation can be accurately reversely analyzed. The detection result shows that the method can be used for accurately determining the content, and the detection accuracy, sensitivity, repeatability and precision are good.

Description

Technical Field

[0001] The present invention relates to the technical field of analysis and detection, in particular to a method for detecting L-malic acid. Background Art

[0002] L-Malic Acid is a pH regulator commonly used in various oral preparations. The existing detection method is titration, which is suitable for the detection of high concentrations of known L-malic acid, but it is difficult to measure the amount of L-malic acid in oral preparations and has low accuracy. Summary of the invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a detection method capable of accurately detecting the amount of L-malic acid in a concentrated oral solution of magnesium sodium potassium sulfate.

[0004] The method for detecting L-malic acid provided by the present invention comprises diluting the sample with a diluent and then performing HPLC detection;

[0005] The diluent consists of water;

[0006] The chromatographic conditions of the HPLC detection include:

[0007] Chromatographic column: C8 reverse phase column;

[0008] Mobile phase: phosphoric acid, water and methanol, isocratic elution.

[0009] In the chromatographic conditions provided by the present invention, the titration method is changed to the HPLC method, so the sample processing method is changed and the operation process is simplified.

[0010] The chromatographic column used in the present invention is a C8 reverse phase chromatographic column, and the chromatographic column StableBond filler is made by chemically bonding a stereoprotected C8 stationary phase to specially treated high-purity ZORBAX porous silica particles. The chromatographic column has good solvent tolerance and can tolerate solvents with a pH of less than 2. In some embodiments, the chromatographic column is a ZORBAX SB-C8 chromatographic column. In some specific embodiments, the size of the chromatographic column is 4.6×150 mm, 5 μm.

[0011] The experiment of the present invention shows that the selection of the chromatographic column, the column temperature and the selection of the mobile phase have a very significant impact on the accuracy of the sample. In some embodiments, the column temperature of the chromatographic column in the detection method of the present invention is 35°C. In the detection method of the present invention, the flow rate of the mobile phase is 1.0mL / min. The elution time of the mobile phase is 30min.

[0012] In the present invention, in the mobile phase, the volume ratio of phosphoric acid, water and methanol is 0.9:90:10.

[0013] In the detection method described in the present invention, the detector of the HPLC is an ultraviolet detector with a detection wavelength of 214 nm.

[0014] In the detection method described in the present invention, the sample loading amount for HPLC detection is 10ul.

[0015] In the detection method described in the present invention, the diluent is water.

[0016] In the present invention, the sample is a concentrated oral solution of magnesium sodium potassium sulfate with L-malic acid added, and the volume ratio of the sample to the diluent is 1:2;

[0017] The sample is a standard product of L-malic acid, and the mass-volume ratio of the sample to the diluent is 50 mg:50 ml.

[0018] The detection method of L-malic acid provided by the present invention is to dilute the sample with a diluent and then perform HPLC detection; the diluent is composed of water; the chromatographic conditions of the HPLC detection include: the chromatographic column is a C8 reverse phase chromatographic column; the mobile phase is composed of phosphoric acid, water and methanol, and isocratic elution. The method provided by the present invention is used for detection, and the amount of L-malic acid in the reference preparation can be accurately analyzed. The test results show that the method of the present invention can accurately determine its content, and the accuracy, sensitivity, repeatability and precision of the detection are all good. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the chromatogram of L-malic acid in the present invention. DETAILED DESCRIPTION

[0020] The present invention provides a method for detecting L-malic acid. Those skilled in the art can refer to the content of this article and appropriately improve the chromatographic parameters to achieve it. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0021] The test materials used in the present invention are all common commercial products and can be purchased on the market. Among them, the oral magnesium sodium potassium sulfate concentrated solution comes from Hubei Wushi Pharmaceutical Co., Ltd., and the L-malic acid reference substance comes from the China Inspection Institute. The ZORBAX SB-C8 chromatographic column comes from Agilent. The present invention is further described below in conjunction with the embodiments:

[0022] Example 1

[0023] 1. Prepare solution

[0024] Test solution: Measure 5 ml of magnesium sodium potassium sulfate oral concentrated solution, place it in a 10 ml volumetric flask, add diluent (water) to dilute to the scale, shake well, and use it as the test solution.

[0025] Reference solution: accurately weigh 50 mg of L-malic acid reference substance and place it in a 50 ml volumetric flask. Add diluent (water) to dissolve and dilute to the scale. Shake well and use it as the reference solution.

[0026] 2. HPLC detection

[0027] Diluent: Water

[0028] Mobile phase: phosphoric acid: water: methanol = 0.9:90:10 (volume ratio)

[0029] Chromatographic column: ZORBAX SB-C8 4.6×150mm, 5μm

[0030] Detection wavelength: 214nm

[0031] Column temperature: 30°C

[0032] Flow rate: 1.0ml / min

[0033] The injection volume was 10ul.

[0034] 2.1 Chromatogram

[0035] Accurately measure 10 μl of the test solution, inject it, and record the chromatogram as shown in Figure 1 .according to Figure 1 , the number of tower plates is 12019.

[0036] 2.2 Repeatability

[0037] Accurately measure 6 portions of 10 μl of the test solution, inject, record the chromatogram, and calculate the results based on the chromatogram:

[0038] sample 1 2 3 4 5 6 RSD Content (g / 176ml) 0.314 0.313 0.315 0.315 0.313 0.314 0.3％ Tailing Factor 1.1 1.1 1.1 1.1 1.1 1.1

[0039] 2.3 System adaptability

[0040] Accurately measure 10 μl of the reference solution, inject reference solution 1 continuously for 5 times, and inject reference solution 2 continuously for 2 times. The recovery rate of the reference solution is 100.2%.

[0041]

[0042] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting L-malic acid, characterized in that: After diluting the sample with a diluent, HPLC detection is performed; The diluent is water; The chromatographic conditions of the HPLC detection include: chromatographic column: C8 reverse phase chromatographic column; Mobile phase: phosphoric acid and methanol, isocratic elution.

2. The detection method according to claim 1, characterized in that: The chromatographic column filler is made by chemically bonding a stereoprotected C8 stationary phase to specially treated high-purity ZORBAX porous silica particles.

3. The detection method according to claim 2, characterized in that: The chromatographic column is a ZORBAX chromatographic column with a size of 4.6×150 mm and 5 μm.

4. The detection method according to any one of claims 1 to 3, characterized in that: The column temperature of the chromatographic column is 35°C.

5. The detection method according to claim 1, characterized in that: In the mobile phase, the volume ratio of phosphoric acid, water and methanol is 0.9:90:

10.

6. The detection method according to claim 1 or 5, characterized in that: The flow rate of the mobile phase is 1.0 ml / min.

7. The detection method according to claim 1, characterized in that: The detector of the HPLC is an ultraviolet detector with a detection wavelength of 214 nm.

8. The detection method according to claim 1, characterized in that: The sample loading amount for the HPLC detection was 10 ul.

9. The detection method according to claim 1, characterized in that: The diluent is water.

10. The detection method according to claim 1 or 9, characterized in that: The sample is a concentrated oral solution of magnesium sodium potassium sulfate with L-malic acid added, and the volume ratio of the sample to the diluent is 1:2; The sample is a standard product of L-malic acid, and the mass-volume ratio of the sample to the diluent is 50 mg:50 ml.

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