CN102156163B - Method for analyzing layered fluorination of diatom sample - Google Patents
Method for analyzing layered fluorination of diatom sample Download PDFInfo
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- CN102156163B CN102156163B CN2010102444367A CN201010244436A CN102156163B CN 102156163 B CN102156163 B CN 102156163B CN 2010102444367 A CN2010102444367 A CN 2010102444367A CN 201010244436 A CN201010244436 A CN 201010244436A CN 102156163 B CN102156163 B CN 102156163B
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- diatom
- diatom sample
- silicon dioxide
- oxygen
- fluoridizing
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Abstract
The invention provides a method for analyzing layered fluorination of a diatom sample, which comprises the following steps of: (1) removing surface oxygen on diatom sample particles; (2) completely fluorinating the diatom sample particles having surface oxygen removed by using a fluorinating agent under a vacuum condition; and (3) converting O2 (Oxygen) generated by the complete fluorination into CO2 (Carbon Dioxide) and carrying out mass spectrum analysis on the CO2 to obtain a delta 18% value of the diatom sample. The method for removing the surface oxygen of the diatom sample comprises the following step of pre-fluorinating the diatom sample particles by using the fluorinating agent under the vacuum condition, wherein in terms of silicon dioxide in the diatom sample particles, the usage of the fluorinating agent used by pre-fluorinating is 40-60 moles relative to 100 moles of silicon dioxide. The analysis method provided by the invention can be used for effectively removing the surface oxygen of the diatom sample particles without need of extra equipment and also largely expanding the application range of a diatom oxygen isotope analytic method while characteristic oxygen isotope information is effectively obtained.
Description
Technical field
The present invention relates to the analytical approach that the layering of a kind of diatom sample is fluoridized.
Background technology
Diatom is that one type of aquatic microbody is biological, and individual morphology is various, and size is between 2-200 μ m, and diatom shell is made up of hydrated SiO 2, belongs to opaline class (opaline silica), also claims biological silicon (biogenic silica), and its molecular composition is (SiO
2NH
2O).After diatom was buried, housing can be stored in the sediment chronically.It is a lot of to influence the environmental factor that the oxygen isotope of diatom forms, and wherein, the factor directly related with the oxygen isotope of housing mainly comprises: the oxygen isotope composition of water body and water temperature and housing were by the influence after burying when housing formed.Therefore, the information of the oxygen isotope of diatom the temperature variation, weather that are writing down water body do wet, the water source changes, the relevant information in precipitation source.In addition, owing to do not have radiological hazard as the oxygen isotope of tracer atom, therefore, oxygen isotope has been widely used in many fields such as industry, agricultural, medical science, pharmacology, biology, geologic chronology, environmental science as tracer atom.
Diatom shell has double-deck chemical constitution, and its inside is the Si-O-Si framework for silicon-oxy tetrahedron, and skin is the Si-OH framework.Internal layer silica Stability Analysis of Structures, oxygen isotope is formed homogeneous, and the oxygen in the layer structure then can freely exchange with extraneous water body at low temperatures.Therefore, obtain diatom shell characteristic oxygen isotope value, then need the top layer oxygen of diatom shell be got rid of.
At present, the method for removing top layer oxygen and obtaining the characteristic oxygen isotope mainly contains 3 kinds: heat-fluoridize mixing method, control isotope exchange method and pyrocarbon reducing process.
(1) heat-fluoridize mixing method: remove through the oxygen of interim high vacuum heating (the maximum temperature section is 1000-1070 ℃) with the hydration layer, sample and BrF then will dewater
5At high temperature react, and the oxygen that displaces is changed into CO
2The confession mass spectrometer is measured.
(2) control isotope exchange method: steam and the commutative component of sample through the known oxygen isotope value are dewatered high-temperature sample (1000 ℃) after (250 ℃) reach balance under the specified temp, and the sample after will dewatering is again fully fluoridized and the oxygen that discharges is processed CO
2, measure oxygen isotope value, through calculating the characteristic oxygen isotope value that obtains diatom shell.
(3) pyrocarbon reducing process: the device through a highly-specialised is accomplished; Sample is placed in the high vacuum reaction cabin that all process with the high purity carbon glass material inside; Be furnished with the inductance heat riser out of my cabin, remove commutative oxygen (this phase temperature is the highest at 1050 ℃), significantly be warming up to 1550-1750 ℃ then through the multistage carbon reduction reaction; Diatom shell and carbon reaction generate CO, need not change into CO
2, and the oxygen isotope of directly testing CO.
The subject matter that above-mentioned three kinds of methods exist is that the requirement height to equipment has limited the application of diatom oxygen isotope analysis method.
Summary of the invention
The objective of the invention is the shortcoming high that exist for the analytical approach that overcomes existing diatom sample, a kind of analytical approach of novel diatom sample is provided equipment requirements.
The invention provides the analytical approach that the layering of a kind of diatom sample is fluoridized, this method comprises:
(1) the top layer oxygen of said diatom sample particle is got rid of; (2) under vacuum condition, the diatom sample particle of having removed top layer oxygen is fluoridized fully with fluorization agent; (3) will fluoridize the O of generation fully
2Change into CO
2, and with CO
2Carry out mass spectrophotometry, to obtain the δ of diatom sample
18O ‰ value; Wherein, The method that the top layer oxygen of said diatom sample is got rid of comprises: under vacuum condition, with fluorization agent the diatom sample particle is fluoridized in advance, in the silicon dioxide in the diatom sample particle; With respect to 100 moles silicon dioxide, the consumption of fluoridizing used fluorization agent in advance is the 40-60 mole.
The oxygen isotope analysis method of diatom sample provided by the invention can be got rid of the top layer oxygen of diatom sample particle effectively; And need not additional apparatus; Under the situation that obtains characteristic oxygen isotope information effectively, also expanded the range of application of diatom oxygen isotope analysis method widely.
Embodiment
The invention provides the analytical approach that the layering of a kind of diatom sample is fluoridized, this method comprises:
(1) the top layer oxygen of said diatom sample particle is got rid of; (2) under vacuum condition, the diatom sample particle of having removed top layer oxygen is fluoridized fully with fluorization agent; (3) will fluoridize the O of generation fully
2Change into CO
2, and with CO
2Carry out mass spectrophotometry, to obtain the δ of diatom sample
18O ‰ value; Wherein, The method that the top layer oxygen of said diatom sample is got rid of comprises: under vacuum condition, with fluorization agent the diatom sample particle is fluoridized in advance, in the silicon dioxide in the diatom sample particle; With respect to 100 moles silicon dioxide, the consumption of fluoridizing used fluorization agent in advance is the 40-60 mole.
According to the present invention, term " δ
18O ‰ value " calculate through following formula:
Wherein, SA representes sample, and ST representes standard model.
Among the present invention, the kind of said standard model is conventionally known to one of skill in the art, for example, can use GBW04405 (quartz) as standard model, δ
18The calculating of O ‰ value is calculated with SMOW (Standard Mean Ocean Water) international standard.
In a kind of preferred implementation of the present invention, in preparatory fluorination process, in the silicon dioxide in the diatom sample particle, with respect to 100 moles silicon dioxide, the consumption of said fluorization agent can be the 45-55 mole.
Said condition of fluoridizing in advance can in very large range change; As long as can make the top layer silicon dioxide complete reaction of fluoridizing used fluorization agent and diatom particle in advance; Under the preferable case, said condition of fluoridizing in advance can comprise: temperature is 500-600 ℃, and the time is 1-3 hour.
Be meant under the said vacuum condition before introducing diatom particle and fluorization agent; With the gas emptying in the reactor to get rid of of the influence of assorted oxygen to analysis result; The pressure limit of said vacuum condition can in very large range change; As long as the gas that can exert an influence to analysis result in the emptying reactor under the preferable case, is evacuated to about 1-5 * 10 with the pressure in the reactor
-3Handkerchief.
According to the present invention; Saidly fluoridize fully, the consumption of fluorization agent can in very large range change, as long as the silicon dioxide in the diatom sample particle is fluoridized fully; For example; In the silicon dioxide in the diatom sample particle of having removed top layer oxygen, with respect to 100 moles silicon dioxide, the consumption of fluorization agent can be the 200-2500 mole; Preferably, with respect to 100 moles silicon dioxide, the consumption of fluorization agent is the 1000-2000 mole.
Said condition of fluoridizing fully can in very large range change; As long as can make the silicon dioxide complete reaction of fluoridizing fully in used fluorization agent and the diatom particle; Under the preferable case, said condition of fluoridizing fully can comprise: temperature is 500-600 ℃, and the time is 3-5 hour.
Among the present invention, be BrF with said fluorization agent
5Be example, the said reaction equation of fluoridizing is:
SiO
2+2BrF
5＝2BrF
3+SiF
4+O
2↑。
Among the present invention; Said fluoridizing in advance with fluoridizing fully can carry out also can in different reactors, carrying out in same reactor; In a kind of preferred implementation of the present invention; Said fluoridizing in advance with fluoridizing in same reactor fully carries out, and method provided by the invention also comprises: before after fluoridizing end in advance, fluoridizing fully, with the O that fluoridizes generation in advance
2Emptying is to avoid fluoridizing in advance the O of generation
2Final mass spectrophotometry is exerted an influence.
Among the present invention, the kind of said fluorization agent is as well known to those skilled in the art, and for example, said fluorization agent can be BrF
5, F
2And IF
5In one or more.
According to the present invention, the purity of said diatom sample particle can be for more than the 90 weight %, and the mean particle diameter of diatom sample particle can be 40-100 μ m.The preparation method who satisfies the diatom sample particle of this purity and mean particle diameter is conventionally known to one of skill in the art.
For example, the preparation method of said diatom sample particle can comprise:
(1) removes organic matter with oxydol; And separate organic fragment with hydro-extractor, concrete step can for: diatom is placed in the beaker, adds concentration and be the oxydol of 10-35 weight % and be heated to 50-80 ℃ and remove organic; In beaker, present suspension; And beaker bottom no longer includes grey black when deposition, sediment is moved into centrifuge tube carry out centrifugally, obtains diatom deposition (organic fragment suspension); Said centrifugal condition can comprise: centrifugal rotation speed is 1500-2500 rev/min, and the centrifugal time is 5-10 minute;
(2) remove carbonate with hydrochloric acid; Concrete steps can for: the HCl that adds concentration in the diatom deposition that obtains centrifugal and be 10-15 weight % handled 20-40 minute; Add 2-5 deionized water doubly; The centrifugal afterwards diatom deposition that obtains, said centrifugal condition can comprise: centrifugal rotation speed is 1500-5000 rev/min, the centrifugal time is 5-10 minute:
(3) using the aperture is the sieve of 100 μ m, and removing mean particle diameter is the above large granular impurities of 100 μ m; And the diatom sample particle that sieves joined carry out flotation in the zinc bromide solution, the diatom particle is because the big natural subsidence downwards of particle, and trickle particle then is suspended in the solution top, treats to remove suspending liquid after the complete sedimentation of diatom particle.Repeated multiple times can be removed fines fraction, and the diatom particle of sedimentation was dried 5-20 minute under 100-200 ℃ condition, and obtaining purity is the above diatom sample particles of 90 weight %.
According to the present invention, detect the δ of diatom sample
18The method of the mass spectrophotometry of O ‰ value is conventionally known to one of skill in the art, for example, the MAT252 type mass spectrometer that uses German Finnigan Mat company to produce, the operation instruction that provides according to manufacturer detects the δ of diatom sample
18O ‰ value.Except as otherwise noted, used reagent is and is purchased product in this detection.
Embodiment 1
(1) the diatom sample particle (Jilin diatomite ore, purity are 95 weight %, and mean particle diameter is 80 μ m) with 10mg places reactor (volume is 24 milliliters), and (pressure is 5 * 10 in that reactor is vacuumized
-3Handkerchief), in reactor, introduce the BrF of 0.07 mM
5(in the diatom sample of 10mg, the molar weight of silicon dioxide is about 0.16 mM), react 1 hour down to remove top layer oxygen at 550 ℃, reaction after finishing is got rid of product, and (pressure is 5 * 10 to recover vacuum
-3Handkerchief);
(2) with the BrF of 1.25 mMs
5Be incorporated in the reactor, reacted 3 hours down at 550 ℃, the diatom sample particle is fluoridized fully with the diatom sample particle of having removed top layer oxygen;
(3) with the O that fluoridizes generation in the step (2)
2Isolate, and be transferred in the carbon stove and be converted into CO
2, afterwards, with CO
2Be incorporated in the MAT252 type mass spectrometer that German Finnigan Mat company produces and carry out mass spectrophotometry; Use GBW04405 (quartz) as standard model; According to SMOW (Standard Mean Ocean Water) standard, calculate the δ of diatom sample according to following formula
18O ‰ value:
Wherein, SA representes sample, and ST representes standard model, and the result is as shown in table 1.
Comparative Examples 1
According to fluoridizing and detect the δ of diatom sample fully with embodiment 1 identical condition
18O ‰ value, difference are the diatom sample not to be fluoridized to remove top layer oxygen in advance, and the result is as shown in table 1.
Embodiment 2
(1) the diatom sample particle (Jilin diatomite ore, purity are 95 weight %, and mean particle diameter is 60 μ m) with 10mg places reactor (volume is 24 milliliters), and (pressure is 2 * 10 in that reactor is vacuumized
-3Handkerchief), in reactor, introduce the F of 0.086 mM
2(in the diatom sample of 10mg, the molar weight of silicon dioxide is about 0.16 mM), react 1 hour down to remove top layer oxygen at 550 ℃, reaction after finishing is got rid of product, and (pressure is 5 * 10 to recover vacuum
-3Handkerchief);
(2) with the F of 2.34 mMs
2Be incorporated in the reactor, reacted 4 hours down at 500 ℃, the diatom sample particle is fluoridized fully with the diatom sample particle of having removed top layer oxygen;
(3) with the O that fluoridizes generation in the step (2)
2Isolate, and be transferred in the carbon stove and be converted into CO
2, afterwards, with CO
2Be incorporated in the MAT252 type mass spectrometer that German Finnigan Mat company produces and carry out mass spectrophotometry; Use GBW04405 (quartz) as standard model; According to SMOW (Standard Mean Ocean Water) standard, calculate the δ of diatom sample according to following formula
18O ‰ value:
Wherein, SA representes sample, and ST representes standard model, and the result is as shown in table 1.
Embodiment 3
(1) the diatom sample particle (Jilin diatomite ore, purity are 95 weight %, and mean particle diameter is 40 μ m) with 10mg places reactor (volume is 24 milliliters), and (pressure is 2 * 10 in that reactor is vacuumized
-3Handkerchief), in reactor, introduce the IF of 0.08 mM
5(in the diatom sample of 10mg, the molar weight of silicon dioxide is about 0.16 mM), react 2 hours down to remove top layer oxygen at 600 ℃, reaction after finishing is got rid of product, and (pressure is 2 * 10 to recover vacuum
-3Handkerchief);
(2) with the IF of 1.92 mMs
5Be incorporated in the reactor, reacted 5 hours down at 600 ℃, the diatom sample particle is fluoridized fully with the diatom sample particle of having removed top layer oxygen;
(3) with the O that fluoridizes generation in the step (2)
2Isolate, and be transferred in the carbon stove and be converted into CO
2, afterwards, with CO
2Be incorporated in the MAT252 type mass spectrometer that German Finnigan Mat company produces and carry out mass spectrophotometry; Use GBW04405 (quartz) as standard model; According to SMOW (Standard Mean Ocean Water) standard, calculate the δ of diatom sample according to following formula
18O ‰ value:
Wherein, SA representes sample, and ST representes standard model, and the result is as shown in table 1.
Table 1
| The embodiment numbering | Embodiment 1 | Comparative Examples 1 | Embodiment 2 | Embodiment 3 |
| δ 18O ‰ value | 29.01 | 23.90 | 28.83 | 28.75 |
Because influencing the external environment condition on diatom sample top layer is poor
18The environment of O, thus diatom sample δ caused
18The reduction of O ‰ value; And can find out that from the data of last table 1 δ 18O ‰ value of the diatom sample that analytical approach provided by the invention detects is not removed δ 18O ‰ value of the method detection of top layer oxygen in the Comparative Examples 1, can explain thus; Analytical approach provided by the invention can be got rid of the top layer oxygen of diatom sample particle effectively; And need not additional apparatus, sample is fluoridized in advance and is fluoridized fully, can in same reactor, realize at times.Under the situation that obtains characteristic oxygen isotope information effectively, also expanded the range of application of diatom oxygen isotope analysis method widely.
Claims (8)
1. the diatom sample layering analytical approach of fluoridizing, this method comprises: the top layer oxygen of diatom sample particle is got rid of in (1); (2) under vacuum condition, the diatom sample particle of having removed top layer oxygen is fluoridized fully with fluorization agent; (3) will fluoridize the O of generation fully
2Change into CO
2, and with CO
2Carry out mass spectrophotometry, to obtain the δ of diatom sample
18O ‰ value; It is characterized in that; The method that the top layer oxygen of said diatom sample particle is got rid of comprises: under vacuum condition, with fluorization agent the diatom sample particle is fluoridized in advance, in the silicon dioxide in the diatom sample particle; With respect to 100 moles silicon dioxide, the consumption of fluoridizing used fluorization agent in advance is the 40-60 mole; Said condition of fluoridizing in advance comprises: temperature is 500-600 ℃, and the time is 1-3 hour.
2. analytical approach according to claim 1, wherein, in preparatory fluorination process, in the silicon dioxide in the diatom sample particle, with respect to 100 moles silicon dioxide, the consumption of fluorization agent is the 45-55 mole.
3. analytical approach according to claim 1, wherein, this method also comprises: before fluoridizing the end back in advance and fluoridizing fully, with the O that fluoridizes generation in advance
2Emptying.
4. analytical approach according to claim 1, wherein, in complete fluorination process, in the silicon dioxide in the diatom sample particle of having removed top layer oxygen, with respect to 100 moles silicon dioxide, the consumption of fluorization agent is the 200-2500 mole.
5. analytical approach according to claim 4, wherein, in complete fluorination process, in the silicon dioxide in the diatom sample particle of having removed top layer oxygen, with respect to 100 moles silicon dioxide, the consumption of fluorization agent is the 1000-2000 mole.
6. according to claim 1,4 or 5 described analytical approachs, wherein, said condition of fluoridizing fully comprises: temperature is 500-600 ℃, and the time is 3-5 hour.
7. according to claim 1,2,4 or 5 described analytical approachs, wherein, said fluorization agent is BrF
5, F
2And IF
5In one or more.
8. analytical approach according to claim 1, wherein, the purity of said diatom sample is more than the 90 weight %, the mean particle diameter of diatom sample particle is 40-100 μ m.
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|---|---|---|---|
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|---|---|---|---|
| CN2010102444367A CN102156163B (en) | 2010-08-03 | 2010-08-03 | Method for analyzing layered fluorination of diatom sample |
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| CN103675087A (en) * | 2013-12-20 | 2014-03-26 | 中国科学院地质与地球物理研究所 | Analytic method of oxygen isotopes in sulfate radicals |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1071348A (en) * | 1990-09-14 | 1993-04-28 | 帝国化学工业公司 | The method of regeneration of fluorination catalyst |
| CN101065429A (en) * | 2004-09-28 | 2007-10-31 | 高级矿物公司 | New functional additive in polymers |
-
2010
- 2010-08-03 CN CN2010102444367A patent/CN102156163B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1071348A (en) * | 1990-09-14 | 1993-04-28 | 帝国化学工业公司 | The method of regeneration of fluorination catalyst |
| CN101065429A (en) * | 2004-09-28 | 2007-10-31 | 高级矿物公司 | New functional additive in polymers |
Non-Patent Citations (1)
| Title |
|---|
| 汉景泰等.湖泊硅藻氧同位素：一种前景广阔的陆相古气候指标.《QUATERNARY SCIENCES》.2006,第26卷(第4期),634-639. * |
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