CN110261418B - Method for accurately determining content of beta-tricalcium phosphate in hydroxyapatite - Google Patents
Method for accurately determining content of beta-tricalcium phosphate in hydroxyapatite Download PDFInfo
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- CN110261418B CN110261418B CN201910627359.4A CN201910627359A CN110261418B CN 110261418 B CN110261418 B CN 110261418B CN 201910627359 A CN201910627359 A CN 201910627359A CN 110261418 B CN110261418 B CN 110261418B
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- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 title claims abstract description 42
- 229910052588 hydroxylapatite Inorganic materials 0.000 title claims abstract description 41
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000001228 spectrum Methods 0.000 claims abstract description 29
- 239000013078 crystal Substances 0.000 claims abstract description 23
- 238000001514 detection method Methods 0.000 claims abstract description 14
- 238000004458 analytical method Methods 0.000 claims abstract description 12
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 238000003991 Rietveld refinement Methods 0.000 claims abstract description 5
- 238000002441 X-ray diffraction Methods 0.000 claims abstract description 5
- 238000004364 calculation method Methods 0.000 claims description 12
- 239000000843 powder Substances 0.000 claims description 5
- 238000004445 quantitative analysis Methods 0.000 claims description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 3
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- 238000011002 quantification Methods 0.000 claims description 3
- 238000007873 sieving Methods 0.000 claims description 2
- 238000007670 refining Methods 0.000 claims 1
- 239000000203 mixture Substances 0.000 abstract description 7
- 238000012545 processing Methods 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 description 6
- 238000011088 calibration curve Methods 0.000 description 4
- 238000007405 data analysis Methods 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- WKBPZYKAUNRMKP-UHFFFAOYSA-N 1-[2-(2,4-dichlorophenyl)pentyl]1,2,4-triazole Chemical compound C=1C=C(Cl)C=C(Cl)C=1C(CCC)CN1C=NC=N1 WKBPZYKAUNRMKP-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004949 mass spectrometry Methods 0.000 description 2
- 229920003196 poly(1,3-dioxolane) Polymers 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 230000004071 biological effect Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000002447 crystallographic data Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000012417 linear regression Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/2055—Analysing diffraction patterns
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- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
A method for accurately determining the content of beta-tricalcium phosphate in hydroxyapatite comprises the steps of carrying out X-ray diffraction measurement on an HA (hydroxyapatite) sample mixed with beta-TCP (beta-TCP) to obtain a diffraction spectrum with high resolution and quality; and (3) constructing effective unit cell parameters and crystal structure models by taking the atomic arrangement structures of the HA crystal and the beta-TCP crystal as templates, and then analyzing each diffraction peak of the diffraction spectrum in a full spectrum range by a Rietveld method by taking the constructed structure models as reference standards to realize the qualitative detection of impurities in the HA and the quantitative detection of the beta-TCP. The invention is based on the correct analysis of the phase composition of the sample and the establishment of reasonable crystal structure of the phase composition, and then takes all diffraction peaks on the diffraction spectrogram as the object of consideration, comprehensively inspects the overall condition of each phase diffraction pattern in the sample to be detected, and carries out data processing by a Rietvelt method to realize high-precision quantitative detection.
Description
Technical Field
The invention relates to a technology in the field of chemical detection, in particular to a method for accurately determining the content of beta-tricalcium phosphate in hydroxyapatite by fitting a full spectrum with an XRD spectrogram.
Background
The artificially synthesized Hydroxyapatite (HA) contains a certain proportion of beta-TCP, and controlling the content of the beta-TCP in the HA is a fundamental means for ensuring the strength and the biological activity, so that an accurate quantitative method for the beta-TCP in the Hydroxyapatite is required. The existing high-performance liquid mass spectrometry requires that a measured object is in a solution state. However, hydroxyapatite is slightly soluble in water, readily soluble in acids and poorly soluble in bases; beta-TCP is insoluble in water, ethanol, etc., and soluble in acid. Similar to HA, after beta-TCP is dissolved in acid, the anion and cation in the solution are Ca respectively2 +And CO3 2-The high performance liquid mass spectrometry cannot distinguish whether calcium ions and carbonate ions come from HA or beta-TCP respectively, and cannot accurately detect the content of the beta-TCP in the HA. Other dissolution solution-based ion detection techniques are also disadvantageous for the detection of beta-TCP in high-purity HA.
In the current pharmaceutical industry standard YY0305-1998, the strongest diffraction peaks (at 2 θ ═ 31.8 ° and 31.0 °) of HA and β -TCP are used as measurement objects, several samples with known content are mixed, and a calibration curve is prepared by a linear regression method for the measurement results. The method has the advantages that only one diffraction peak of each phase is selected for measurement, and the test is influenced by the preferred orientation and the grain size of the crystal, so that the accuracy of the measurement result is not high. Other methods such as reference intensity method (RIR), K value method and the like are also based on unimodal estimation, and the accuracy of the measurement result is not ideal.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method for accurately measuring the content of beta-tricalcium phosphate in hydroxyapatite, which is a high-precision quantitative method for comprehensively investigating the overall condition of each phase diffraction pattern in a measured sample by taking all diffraction peaks on a diffraction spectrogram as a consideration object based on the correct analysis of the phase composition of the sample and the construction of a reasonable crystal structure of phase components and carrying out data processing by a Rietvelt method.
The invention is realized by the following technical scheme:
the method obtains a high-resolution diffraction spectrum by carrying out X-ray diffraction measurement on an HA sample mixed with beta-TCP; and (3) constructing effective unit cell parameters and crystal structure models by taking the atomic arrangement structures of the HA crystal and the beta-TCP crystal as templates, and then analyzing each diffraction peak of the diffraction spectrum in a full spectrum range by a Rietveld method by taking the constructed structure models as reference standards to realize the qualitative detection of impurities in the HA and the quantitative detection of the beta-TCP.
The unit cell parameters are as follows: three crystal axes a, b, c and their included angles α, β, γ describe the size and shape of the HA or β -TCP unit cell.
The crystal structure model includes but is not limited to: atomic arrangement, atomic coordinates and atomic occupancy in HA or β -TCP.
The sample is preferably ground by an agate bowl and then sieved by a 250-mesh sieve.
The X-ray diffraction measurement adopts but is not limited to a diffractometer sample stage, the sample is placed into the diffractometer to perform theta/theta coupling scanning after being loaded, the sample rotates at the speed of 50 revolutions per minute during scanning, the 2 theta scanning starting angle is not higher than 10 degrees, the stopping angle is not lower than 90 degrees, the step length is 0.02 degree, and 2.5-degree cable-stayed slits are respectively arranged in front of and behind the diffractometer sample stage.
The Rietveld method analysis refers to that: and (3) performing optimal approximate fitting on the calculated diffraction peak shape and the actually measured diffraction peak shape by correcting the parameters of the atomic structure model on the powder diffraction spectrogram by adopting a least square method.
The qualitative detection is as follows: and (4) judging the components of the sample phase and whether impurities exist in the sample phase by introducing the diffraction spectrogram into phase search/matching analysis software.
The quantitative detection means that: performing full spectrum fitting quantitative analysis on the diffraction spectrogram with high resolution quality, constructing an analysis calculation model by using the crystal structure of HA in a hexagonal system and a P63/m space group and the crystal structure of beta-TCP in a monoclinic system and an R-3m space group, and calculating by using software which can refine powder diffraction spectrum, such as TOPAS or PDXL and the like to obtain the mass percent of HA and beta-TCP in the sample.
Technical effects
Compared with the existing RIR method that the analysis limit of the beta-TCP is 1%, the analysis limit of the beta-TCP is lower and can reach 0.5%, and the minimum quantitative limit can reach 1% of the beta-TCP. The invention does not need to use a standard sample and do not need to make a calibration curve, thereby avoiding purchasing or preparing the standard sample and a series of experiments related to the calibration curve and saving the cost of capital and time.
Drawings
FIGS. 1a and 1b are graphs of XRD phase retrieval spectrum and full spectrum fit calculation of example 1;
FIGS. 2a and 2b are graphs of XRD phase retrieval spectrum and full spectrum fit calculations for example 2;
FIGS. 3a and 3b are graphs of the XRD phase retrieval spectrum and full spectrum fit calculations for example 3;
fig. 4a and 4b are graphs of XRD phase retrieval spectrum and full spectrum fitting calculation results of example 4.
Detailed Description
Example 1
The embodiment specifically comprises the following steps:
step 1) grinding the HA/beta-TCP mixture by using an agate bowl, and then sieving the mixture by using a 250-mesh sieve;
step 2) weighing 0.5g +/-0.01 g of HA/beta-TCP mixture, filling the mixture into a diffractometer sample stage, enabling the compactness of sample powder to be proper and the surface to be smooth, then placing the sample into the diffractometer for theta/theta coupling scanning, enabling the sample to rotate at the speed of 50 revolutions per minute during scanning, enabling the 2 theta scanning starting angle to be not higher than 10 degrees, the stopping angle to be not lower than 90 degrees, enabling the step length to be 0.02 degree, and respectively placing 2.5-degree rope-pulling slits in front of and behind the diffractometer sample stage;
step 3) after collecting diffraction data, importing a diffraction spectrogram into phase search/matching analysis software, and judging whether the sample phase component is HA/beta-TCP and other impurities except the beta-TCP exist;
and 4) further performing full spectrum fitting quantitative analysis on the spectrogram without other obvious impurity peaks, constructing an analysis calculation model by using the crystal structure of HA in a hexagonal system and a P63/m space group and the crystal structure of beta-TCP in a monoclinic system and an R-3m space group, and calculating by using software with a fine modification function, such as TOPAS or PDXL and the like to obtain the mass percent of HA and beta-TCP of the detected sample.
As shown in FIGS. 1a and 1b, in this example, no other phases than HA and β -TCP were present by measurement and data analysis of sample # 1. Calculation of full spectrum fit was performed using TOPAS software, with a residual factor Rwp of 6.5%, yielding a sample with an HA content of 98.09%.
Example 2
And (4) carrying out determination and data analysis on the sample No. 2. The results of the search software analysis are shown in FIG. 2a, with no other phases present except HA and β -TCP. Calculation of the full spectrum fit using TOPAS software, with a residual factor Rwp of 8.7%, gave a sample HA content of 96.38%, see fig. 2 b.
Example 3
And (4) carrying out determination and data analysis on the sample No. 3. The results of the search software analysis are shown in FIG. 3a, with no other phases present except HA and β -TCP. Calculation of the full spectrum fit using TOPAS software with a residual factor Rwp of 8.5% gave a sample HA content of 95.10%, see figure 3 b.
Example 4
And (4) carrying out determination and data analysis on the sample # 4. The results of the analysis of the search software are shown in fig. 4a, and in addition to HA and β -TCP, a diffraction peak at 12 ° 2 θ indicates the presence of additional phases. The calculation of the full spectrum fit using TOPAS software, with a residual factor Rwp of 23.8% and a diffraction peak at 2 θ of 12 ° did not result in a valid fit to the established model of the HA and β -TCP crystal structures, see fig. 4b, which judged that the sample did contain other impurities, but the ratio of the amounts of HA (93.84%) and β -TCP (6.16%) in the sample was still valid.
Through specific practical experiments, under the working conditions of 40kV and 40mA of Cu targets and in the test environment that an array detector and an incident and receiving light path are respectively provided with 2.5 cable-pulling slits, a spectrum is acquired at the scanning speed of 2 degrees/minute, the full-spectrum fitting calculation is operated, and the obtained experimental data are as follows: HA content values as listed in figures 1-4.
Compared with the prior art, the performance index of the method is improved as follows: the analysis limit and the quantification limit of the beta-TCP contained in the HA are improved, the complicated preparation process of a calibration curve is avoided, and the quantification technology of the HA/beta-TCP is more accurate. The reasonable refinement of the parameters of the HA unit cell is the key to the realization of the invention.
The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (1)
1. A method for determining the content of beta-tricalcium phosphate in hydroxyapatite with analysis limit of 0.5 percent and minimum quantification limit of 1 percent is characterized in that a high-resolution diffraction spectrum is obtained by carrying out X-ray diffraction measurement on an HA sample mixed with beta-TCP; taking the atomic arrangement structures of HA crystals and beta-TCP crystals as templates to construct effective unit cell parameters and crystal structure models, and then taking the constructed structure models as reference standards to analyze each diffraction peak of a diffraction spectrum in a Rietveld method in the full spectrum range, so as to realize the qualitative detection of impurities in HA and the quantitative detection of beta-TCP;
the unit cell parameters are as follows: three crystal axes a, b, c describing the size and shape of the HA or β -TCP unit cell and their included angles α, β, γ;
the crystal structure model comprises: atomic arrangement mode, atomic coordinate and atomic occupancy in HA or beta-TCP;
grinding the sample by an agate bowl and then sieving the ground sample by a 250-mesh sieve;
in the X-ray diffraction measurement, a diffractometer sample stage is adopted, the sieved sample powder is placed into the diffractometer to perform theta/theta coupling scanning, the sample rotates at the speed of 50 revolutions per minute during scanning, the 2 theta scanning starting angle is not higher than 10 degrees, the stopping angle is not lower than 90 degrees, the step length is 0.02 degree, and 2.5-degree cable-stayed slits are respectively arranged in front of and behind the diffractometer sample stage;
the Rietveld method analysis refers to that: the method of least square method is adopted to make the calculated diffraction peak shape and the actually measured diffraction peak shape reach the best approximate fitting through the method of correcting the parameters of the atomic structure model;
the qualitative detection is as follows: judging the phase components of the sample and whether impurities exist in the phase components by introducing the diffraction spectrogram into phase search/matching analysis software;
the quantitative detection refers to: and performing full spectrum fitting quantitative analysis on the spectrogram without the impurity peak, constructing an analysis calculation model by using the crystal structure of HA in a hexagonal system and a P63/m space group and the crystal structure of beta-TCP in a monoclinic system and an R-3m space group, and calculating by adopting software capable of refining the powder diffraction spectrum to obtain the mass percent of HA and beta-TCP in the sample.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102497891A (en) * | 2009-06-23 | 2012-06-13 | 盖斯特里希医药公司 | Bone substitute material |
| CN105327390A (en) * | 2015-10-23 | 2016-02-17 | 华南理工大学 | Controllable-phase strontium-doped calcium phosphate powder and preparing method thereof |
| CN108290737A (en) * | 2015-09-25 | 2018-07-17 | 清洁世界技术有限公司 | Produce calcium phosphate compositions |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US8409538B2 (en) * | 2008-12-04 | 2013-04-02 | Skeletal Kinetics Llc | Tricalcium phosphate coarse particle compositions and methods for making the same |
| CN108802075B (en) * | 2018-06-26 | 2023-09-15 | 湘潭大学 | Method for measuring content of each phase in powder zinc impregnation layer |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102497891A (en) * | 2009-06-23 | 2012-06-13 | 盖斯特里希医药公司 | Bone substitute material |
| CN108290737A (en) * | 2015-09-25 | 2018-07-17 | 清洁世界技术有限公司 | Produce calcium phosphate compositions |
| CN105327390A (en) * | 2015-10-23 | 2016-02-17 | 华南理工大学 | Controllable-phase strontium-doped calcium phosphate powder and preparing method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 《Ionic Substitutions in Biphasic Hydroxyapatite and β-Tricalcium Phosphate Mixtures:Structure Analysis by Rietveld Refinement》;Kannan等;《journal of the American ceramic society》;20080131;第91卷(第1期);第1-12页 * |
| 《四川石棉软玉猫眼和蛇纹石猫眼的宝石矿物学及其谱学研究》;卢保奇;《中国博士学位论文全文数据库 基础科学辑》;20070115(第1（2007）期);第28页 * |
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