Method for measuring content of iron element in etimicin sulfate

Abstract

The invention provides a method for determining the content of an iron element in etimicin sulfate, which comprises the following steps: step 1, preparing a diluent; step 2, preparing a test solution; step 3, determination: taking a diluent and the test solution, injecting the diluent and the test solution into an atomic absorption spectrometer to obtain a spectrogram, and calculating the content of the iron element in the test solution according to the spectrogram; wherein the detection conditions of the atomic absorption spectrometer are as follows: flame type: acetylene / air; the gas flow rate of acetylene is 2.0 L / min, and the gas flow rate of air is 13.5 L / min; a manual sampling mode is adopted; the wavelength is 589.0 nm; and the background correction requirement is BC OFF.

Description

Technical Field

[0001] This invention relates to a drug detection method, and more particularly to a method for determining the iron content in etimicin sulfate. Background Technology

[0002] Etimicin sulfate is a chemical substance, with the English name Etimicin Sulfate, CAS number 362045-44-1, molecular weight 1445.58, and molecular formula (C 21 H 43 N5O7)2·5H2SO4, its structural formula is as follows:

[0003]

[0004] Etimicin sulfate is an aminoglycoside semi-synthetic antibiotic, suitable for various infections caused by susceptible Escherichia coli, Klebsiella pneumoniae, Serratia spp., Citrobacter spp., Enterobacter spp., Acinetobacter spp., Proteus spp., Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus.

[0005] To improve product quality and control heavy metal content, a method for determining the iron content in etimicin sulfate was developed.

[0006] The Chinese Pharmacopoeia publishes the principles for determining iron content in drugs. These principles apply to the determination of aluminum, chromium, iron, and barium in traditional Chinese medicines, excluding mineral drugs or preparations containing mineral drugs, and can be used in conjunction with the methods for determining lead, cadmium, arsenic, mercury, and copper (General Rule 2321). The preferred basic method is inductively coupled plasma mass spectrometry (ICP-MS), which involves simultaneous determination of multiple elements (General Rule 0412). Other methods with comparable sensitivity to ICP-MS can also be used.

[0007] GB 5009.90-2016, the national food safety standard, specifies methods for determining the iron content in food, such as flame atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, and inductively coupled plasma mass spectrometry.

[0008] Chinese patent CN103499482A discloses a sample digestion method for determining the iron content in drugs. This invention uses nitric acid with a concentration of 15-40%, and the iron in the drug can be completely digested through soaking and boiling reflux. The digested sample solution can be diluted and then further subjected to atomic absorption spectrophotometry for iron content determination.

[0009] Chinese patent CN102841176A discloses a method for detecting the iron content in the Tibetan medicine composition Zhenlong Xingnao capsules and its preparations, which uses a mercury-free potassium dichromate titration method to detect the iron content in the Tibetan medicine composition Zhenlong Xingnao capsules.

[0010] Based on existing technologies, this invention provides a novel method for determining iron content. Summary of the Invention

[0011] This invention provides a method for determining the iron content in etimicin sulfate, the method comprising the following steps:

[0012] Step 1, Preparation of diluent

[0013] Step 2, Preparation of test solution

[0014] Step 3, determination: Take the diluent and the test solution, inject them into the atomic absorption spectrometer, obtain the spectrum, and calculate the iron content in the test solution based on the spectrum;

[0015] The detection conditions for the atomic absorption spectrometer are as follows:

[0016] Flame type: Acetylene / air

[0017] Gas flow rates: Acetylene 2.0 L / min, Air 13.5 L / min

[0018] Measurement mode: Integration

[0019] Sample introduction mode: Manual

[0020] Wavelength: 589.0nm

[0021] Background correction requirements: BC OFF

[0022] In this invention, the diluent in step 1 is a nitric acid solution, preferably a nitric acid solution with a volume ratio of 5-15%, and most preferably a nitric acid solution with a volume ratio of 10%. In this invention, the preparation of the test sample solution in step 2 involves dissolving etimicin sulfate raw material or a pharmaceutical preparation containing etimicin sulfate using a diluent, and, if necessary, processing it by filtration or centrifugation, to obtain the test sample solution. Preferably, the concentration of the test sample solution in this invention is 0.01-0.1% by weight / volume, and most preferably 0.2%. This invention further provides a method for preparing an iron element standard curve. The method includes accurately weighing 0.5 ml of iron element standard solution, placing it in a 50 ml plastic volumetric flask, diluting it to the mark with the diluent prepared in this invention, and shaking well to obtain a reference standard stock solution; further preparing five test solutions of different concentrations, detecting them using the detection conditions of the atomic absorption spectrometer described in this invention, obtaining spectra, and plotting the correspondence between the spectral data of the spectra and the concentrations of the test solutions using analytical geometry to form a standard curve.

[0023] In this invention, the determination in step 3 involves injecting the test sample solution using the detection conditions of the atomic absorption spectrometer described in this invention to obtain spectral data, and then converting the spectral data into the iron content of the test sample solution based on its position on the standard curve.

[0024] The advantages of this invention are:

[0025] 1. The test solution is easy to prepare, requires no special digestion equipment, and is highly safe.

[0026] 2. The present invention is easy to operate and has high detection efficiency.

[0027] This invention does not employ existing technology, which has the following drawbacks:

[0028] 1. Existing technologies cannot be directly used for the detection of etimicin sulfate raw material.

[0029] 2. The preparation of the test solution is relatively complex and requires specialized digestion equipment. Attached Figure Description

[0030] Figure 1 A standard curve of the iron standard solution prepared using the method of the present invention under the detection conditions of the atomic absorption spectrometer described in the present invention. Detailed Implementation

[0031] The present invention is further illustrated by the following examples, but these are not intended to limit the invention.

[0032] Example 1

[0033] The iron content in etimicin sulfate was determined by the following method.

[0034] 1. Chromatographic conditions:

[0035]

[0036] 2. Solution preparation:

[0037]

[0038]

[0039] 3. Determination: Take the diluent and the test solution, inject them into the atomic absorption spectrometer, and perform linear regression analysis on the iron concentration and corresponding absorbance of each linear solution to calculate the iron content in the test solution. The results are as follows:

[0040] serial number absorbance Iron (ppm) Test sample 1 13.8952 1.38 Test sample 2 13.2546 1.33

[0041] Example 2

[0042] Preparation of standard curve

[0043]

[0044] The detection was performed using the atomic absorption spectrometer described in this invention, and the results are as follows:

[0045] serial number Concentration (μg / ml) absorbance STD-0 0 0.2061 STD-1 50 2.4428 STD-2 100 5.0864 STD-3 200 10.0967 STD-4 300 14.9428 STD-5 500 24.3949

[0046] Plot a standard curve of the iron standard solution prepared using the method of the present invention under the detection conditions of the atomic absorption spectrometer described in the present invention.

Claims

1. A method for determining the iron content in etimicin sulfate, the method comprising the following steps: Step 1, Preparation of diluent Step 2, Preparation of test solution Step 3, determination: Take the diluent and the test solution, inject them into the atomic absorption spectrometer, obtain the spectrum, and calculate the iron content in the test solution based on the spectrum; The detection conditions for the atomic absorption spectrometer are as follows: Flame type: Acetylene / air Gas flow rates: Acetylene 2.0 L / min, Air 13.5 L / min Measurement mode: Integration Sample introduction mode: Manual Wavelength: 589.0nm Background correction requirement: BC OFF.

2. The method according to claim 1, characterized in that, The diluent mentioned in step 1 is a nitric acid solution.

3. The method according to claim 1, characterized in that, The concentration of the nitric acid solution is 5-15% by volume.

4. The method according to claim 1, characterized in that, The nitric acid solution is a nitric acid solution with a volume ratio of 10%.

5. The method according to claim 1, characterized in that, The preparation of the test solution in step 2 involves dissolving etimicin sulfate raw material or a drug preparation containing etimicin sulfate using a diluent, and if necessary, processing it by filtration or centrifugation, to obtain the test solution.

6. The method according to claim 1, characterized in that, The concentration of the test solution is 0.01-0.1% by weight / volume.

7. The method according to claim 1, characterized in that, The concentration of the test solution is 0.2% by weight / volume.

8. The method according to claim 1, characterized in that, The determination in step 3 involves injecting the test sample solution into the atomic absorption spectrometer described in this invention under the detection conditions to obtain spectral data. The spectral data is then converted into the iron content of the test sample solution based on its position on the standard curve.

9. A method for preparing a standard curve for iron, the method comprising: accurately weighing 0.5 ml of iron standard solution and placing it in a 50 ml plastic volumetric flask; diluting it to the mark with the diluent prepared by the method of claim 4; shaking well to obtain a reference stock solution; further preparing five test solutions of different concentrations; detecting them using the detection conditions of the atomic absorption spectrometer of claim 1 to obtain spectra; and plotting the correspondence between the spectral data of the spectra and the concentrations of the test solutions using analytical geometry to form a standard curve. The five solutions of different concentrations are as follows:

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