CN104596965B - Determination method of concentration of iron ion in algae nutrient - Google Patents
Determination method of concentration of iron ion in algae nutrient Download PDFInfo
- Publication number
- CN104596965B CN104596965B CN201510056756.2A CN201510056756A CN104596965B CN 104596965 B CN104596965 B CN 104596965B CN 201510056756 A CN201510056756 A CN 201510056756A CN 104596965 B CN104596965 B CN 104596965B
- Authority
- CN
- China
- Prior art keywords
- sample
- concentration
- nutritive salt
- algae
- citrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The invention relates to a determination method of iron ions and in particular relates to a determination method of the concentration of iron ion in an algae nutrient. The determination method comprises the following steps: preparing a ferric citrate standard liquid with ferric ion concentration of 6*10＜-3＞mol/L; diluting the standard liquid into diluents with different concentrations, measuring the average absorbance of the diluents at 450nm by utilizing an ultraviolet spectrophotometer, and drawing a standard curve; determining an absorbance value of a sample at 450nm, and calculating the concentration of the ferric ion in the sample according to the standard curve; and subtracting the actually measured concentration of the ferric ion from the initial concentration of the ferric ion in the sample to acquire the concentration of the ferrous ion in the sample. The determination method is capable of quantitatively detecting the contents of ferric citrate and ferrous citrate in a stock solution of the algae nutrient, is simple and rapid and is high in accuracy, wide in detection range and little in middle process without addition of other agents and pretreatment of the sample, so that the test cost is low, and the time is short.
Description
Technical field
The present invention relates to a kind of assay method of iron ion, particularly to a kind of survey of iron concentration in algae nutritive salt
Determine method.
Background technology
Nowadays, algae scientific research and production scale grow stronger day by day, and in industrial production and laboratory cultures, ferro element is always algae
Critical nutrients in class nutritive salt.Different algal species require difference to the price of ferro element, and some algae need ferric iron, and
Other need ferrous iron.Conventional ferro element nutritive salt is mainly the complex compound of citric acid and iron, i.e. ironic citrate or citric acid
Ferrous.Ironic citrate is being prepared and is partly being reduced to ferrous citrate during depositing, and ferrous citrate is being prepared and deposited
During be easily oxidized to ironic citrate, both storage liquid all can form the mixture of ironic citrate and ferrous citrate,
The iron ion of different chemistry prices and variable concentrations then have impact on the normal growth of algae, how correctly to measure algae nutrition
The content of the ironic citrate in salt and ferrous citrate is most important to the culture of algae.
But, propagate artificially or laboratory research in, in algae nutritive salt the content of ironic citrate and ferrous citrate by
Create notable difference in factors such as reagent preparation, compound method and holding conditions.Only has the side of quantitative determination ferro element at present
Method, but the mixture for ironic citrate and ferrous citrate, the method that there is no quantitative determination, do not determine yet ironic citrate with
The method of the ratio of ferrous citrate, causes inconvenience to production and scientific research.
Content of the invention
It is an object of the invention to provide in a kind of algae nutritive salt iron concentration assay method, the method pass through ultraviolet
AAS is real-time, the content of quantitative determination ironic citrate, also can calculate the content of ferrous citrate simultaneously, simple, quick,
Accuracy rate height, detection range width, testing cost are low.
In order to realize above technique effect, the present invention is to be achieved by the steps of：
The assay method of iron concentration in a kind of algae nutritive salt, its step includes：
(1) preparing ferric ion concentration is 6 × 10-3The ironic citrate titer of mol/L, is cooled to 18-25 DEG C；Select
This ferric ion concentration deviation standard is little, and error is little.
(2) the ironic citrate titer in step (1) is diluted to the dilution of variable concentrations, using light absorbs ELIASA
Record absorbance values at 450nm for the ironic citrate dilution, with A450 mean value as ordinate, to should absorbance
Iron concentration be abscissa, draw standard working curve；Select to survey absorbance at 450nm, draw calibration curve, no
Then calibration curve is non-linear.
(3) measure absorbance at 450nm for the algae nutritive salt sample, according to the standard work drawn in step (1)
Curve, calculates the ferric ion concentration in sample；Select to survey absorbance at 450nm, the light absorption value of ironic citrate exists
Between 0.1-0.5, and ferrous citrate light absorption value is 0, can distinguish ironic citrate and ferrous citrate both materials well.
(4) initial concentration of the ferric ion in algae nutritive salt storage liquid sample deducts the actual measurement three in step (2)
Valency iron concentration, is the ferrous ion concentration in algae nutritive salt sample.
In described step (2), the ferric ion concentration in ironic citrate dilution is 0,0.6 × 10-3mol/L、1.2×
10-3mol/L、2.4×10-3mol/L、4.8×10-3Mol/L and 6 × 10-3mol/L.
The composition of described algae nutritive salt sample is the mixed liquor of ironic citrate and ferrous citrate.
In described step (1), open-assembly time is less than 3 minutes the ironic citrate titer after preparing in atmosphere.Avoid
Ironic citrate is reduced.
In described step (2), during titer dilution, the dilution of employing is anaerobic distilled water.
In described step (2), mixing in dilution standard liquid can be it is impossible to produce bubble, and Ambient Operating Temperature is less than
25℃.Avoid ironic citrate to be reduced.
In described step (3), before algae nutritive salt sample determination, by sample at 4 DEG C sealing preserve and gas can not be mixed with
Bubble, open-assembly time is less than 3 minutes sample in atmosphere.
The composition of described algae nutritive salt sample is ironic citrate.
The beneficial effect of the invention is：1st, in the algae nutritive salt that the present invention provides, the assay method of iron concentration can be real-time
The content of citric acid iron-based ferrous citrate in liquid stored by quantitative determination algae nutritive salt, simple, quick, and accuracy rate is high, detection
Wide ranges.2nd, this assay method is few due to pilot process, need not add other reagent, and sample need not pre-process, thus compares GB
Method is more nearly actual value, and testing cost is low, the time is short.3rd, this detection method can directly measure ironic citrate, in microalgae field
Use, with strong points, sensitivity is high,
During calculation error, because National Standard Method can not directly measure ironic citrate content, thus measure citric acid with National Standard Method
Ferrous reckoning ironic citrate content, and the direct ironic citrate measuring compares with this method.
Brief description
Fig. 1 is brand-new ironic citrate and ferrous citrate spectrum correlation curve in embodiment 1.
Fig. 2 is ironic citrate canonical plotting in embodiment 1.
Fig. 3 is in embodiment 3, ironic citrate canonical plotting when being detected using National Standard Method.
Specific embodiment
With reference to embodiment, the invention will be further described：
The used equipment of experiment：Uv analyzer UV-1800.
The used reagent of experiment：Citric Acid Mono (C6H8O7·H20), Ferric Ammonium Citrate (C6H10FeNO8), ferrous sulfate
(FeSO4·7H2O), anaerobic distilled water；
National Standard Method reagent：Hydroxylamine hydrochloride (HO-NH2HCl), Phen (C12H8N2·H2O), 1mol/L sodium acetate
(CH3COONa), metallic iron, hydrochloric acid, distilled water.
1st, the preparation of titer
Take citric acid 0.3g, Ferric Ammonium Citrate 0.3g, with the distilled water boiling, citric acid and Ferric Ammonium Citrate are dissolved, mix
It is settled to 100mL after conjunction, be cooled to 18-25 DEG C, ferric ion final concentration of 6 × 10-3The ironic citrate titer of mol/L.
This ironic citrate is now with the current, and after preparing, open-assembly time is less than 3 minutes in atmosphere.
Take citric acid 0.3g, ferrous sulfate (FeSO4·7H2Citric acid is first dissolved by O) 0.17g with the distilled water boiling,
Again ferrous sulfate is dissolved, after mixing, be settled to 100mL, be cooled to 18-25 DEG C, ferrous ion final concentration of 6 × 10-3mol/
The ferrous citrate titer of L.
2nd, the drafting of standard working curve
Take ironic citrate titer and the ferrous citrate titer of the preparation of 3mL above-mentioned steps respectively, use ultraviolet spectrometry light
Degree meter measure absorption spectrum (190nm-750nm), find at 450nm, the light absorption value of ironic citrate between 0.1-0.5, and
Ferrous citrate light absorption value is 0, specifically as shown in figure 1, so choosing A450 is measured value.
Take the centrifuge tube of 6 1.5mL, according to the additional proportion of following table, the citric acid solution preparing variable concentrations is (single
Position：μL)
| 1 | 2 | 3 | 4 | 5 | 6 | |
| Anaerobic distilled water | 1000 | 900 | 800 | 600 | 200 | 0 |
| Titer | 0 | 100 | 200 | 400 | 800 | 1000 |
If dry hole is taken on ELISA Plate, it is separately added into the citric acid solution 200 μ L of each concentration in 1-6 pipe in upper table,
The A450 value in each hole is measured on ELIASA, repeatedly, and calculates the average of A450 in each group # identical holes respectively
Value, and with A450 mean value as ordinate, to should the Ferric Citrate concentration of absorbance be abscissa, draws standard work bent
Line, is shown in Fig. 2.
3rd, sample determination
Take each 250mL of algae nutritive salt sample solution of new preparation, this sample is protected in 4 DEG C of sealings.This sample solution
Composition is ferrous citrate, and the theoretical concentration of its ferrous ion is 6 × 10-3Mol/L, tests its trivalent between placing 7 days
Iron ion and ferrous ion concentration change.
When placing 1 day, by algae nutritive salt sample solution on ELISA Plate, measure its A450 value, substitute into standard work bent
Line, calculates Ferric Citrate concentration, show that the concentration of ferric ion is 1.6 × 10-3Mol/L, the concentration of ferrous ion is 4.4
×10-3mol/L.
According to the method described above, ironic citrate when 1 day, 2 days, 3 days, 4 days, 5 days, 6 days and 7 days and citric acid are placed in detection
Ferrous concentration, shown in table 1 specific as follows：
Iron concentration change table in table 1 ferrous citrate storage liquid
As can be seen from Table 1, after placing one week, ferrous citrate is gradually oxidized to ironic citrate.
Embodiment 2
1st, the drafting of calibration curve is with embodiment 1.
2nd, take brand-new and seal each 250mL of ironic citrate titer depositing a week on ELISA Plate, measure A450 value, generation
Enter in calibration curve, calculate Ferric Citrate concentration, result such as table 2 below：
Ironic citrate content in table 2 ironic citrate storage liquid
| Brand-new ironic citrate | 0.4 times of brand-new ironic citrate | Place the ironic citrate of a week |
| 5.9×10-3mol/L | 3.58×10-3mol/L | 4.2×10-3mol/L |
After placing one week, ironic citrate partial reduction is ferrous citrate, so, the concentration of ferrous citrate is 1.7 ×
10-3mol/L.
Embodiment 3
Accuracy rate is verified：Measure ironic citrate according to national standard method (GB7873-87,3).
Principle：Ferric iron hydrochloric acid hydrogen amine Restore All is ferrous iron, then surveys with Phen reacting generating complex
Fixed total iron；Measure divalence iron content using Phen and ferrous iron reacting generating complex.
1st, reagent：10% hydroxylamine hydrochloride solution (is newly joined)；
O-phenanthrolin developer：The 0.15% Phen aqueous solution；
Sodium acetate solution (1mol/L)；
Iron (Fe) standard liquid (0.2 × 10-3mol/L)：Accurately weigh simple metal iron powder or pure iron silk (is first washed away with hydrochloric acid
Oxide on surface), it is dissolved in watery hydrochloric acid, heating for dissolving.
2 Specification Curve of Increasings
2.1 standards systems/5ml
Prepare standards system according to table 3 below
Table 3
| Composition | Fe titer | 10% hydroxylamine hydrochloride | 0.15% Phen | Sodium acetate | Distilled water |
| Mark 1 (ml) | 0 | 0.5 | 1 | 2.5 | 1 |
| Mark 2 (ml) | 0.2 | 0.5 | 1 | 2.5 | 0.8 |
| Mark 3 (ml) | 0.4 | 0.5 | 1 | 2.5 | 0.6 |
| Mark 4 (ml) | 0.6 | 0.5 | 1 | 2.5 | 0.4 |
| Mark 5 (ml) | 0.8 | 0.5 | 1 | 2.5 | 0.2 |
| Mark 6 (ml) | 1 | 0.5 | 1 | 2.5 | 0 |
2.2 ELIASAs measure
Take each 250ul of standards system 1-6 to drip on ELISA Plate respectively, measure A510 and draw calibration curve, as Fig. 3 institute
Show.
Table 4
3 sample determinations
3.1 sample standard liquid
By the ironic citrate titer dilution of brand-new in example 2 so that ferric iron final concentration of 0.2 × 10-3mol/l.
3.2 sample systems/5ml
Prepare according to table 5 below
Table 5
3.3 sample determination
Take 250ul ELISA Plate method or cuvette method to measure A510, substitute into calibration curve, acquired results are as shown in table 6 below：
Table 6
From shown in table 6, National Standard Method is more due to pilot process, and sample pretreatment is difficult to avoid that loss, thus gap is larger.
When this method directly measures ironic citrate content, other reagent need not be added, sample need not pre-process, thus is more nearly reality
Value.
Embodiment 4
Ferrous citrate is measured using National Standard Method (GB7873-87,3)
4.1 sample standard liquid
By brand-new in embodiment 1 and the ferrous citrate titer dilution deposited so that ferrous iron final concentration of 0.2 ×
10-3mol/L.
4.2 sample systems/5ml
Prepare according to table 7 below：
Table 7
| Numbering | Deposit number of days (my god) | Sample liquid (ml) | 0.15% Phen (ml) | Sodium acetate (ml) | Distilled water (ml) |
| 1 | 1 | 1 | 1 | 2.5 | 0.5 |
| 2 | 2 | 1 | 1 | 2.5 | 0.5 |
| 3 | 3 | 1 | 1 | 2.5 | 0.5 |
| 4 | 4 | 1 | 1 | 2.5 | 0.5 |
| 5 | 5 | 1 | 1 | 2.5 | 0.5 |
| 6 | 6 | 1 | 1 | 2.5 | 0.5 |
| 7 | 7 | 1 | 1 | 2.5 | 0.5 |
4.3 sample determination
The new algae nutritive salt sample solution prepared in Example 1, takes 250ul ELISA Plate method or cuvette method to measure
A510, substitutes into the National Standard Method calibration curve of example 3 gained, and acquired results are as shown in table 8 below：(unit：10-3mol/L)
Table 8
During calculation error, because National Standard Method can not directly measure ironic citrate content, thus measure citric acid with National Standard Method
Ferrous reckoning ironic citrate content, and the direct ironic citrate measuring compares with this method.
Although totally ferrous measurement result rule compared with this method is identical for National Standard Method, content is relatively low；National Standard Method measures
During brand-new ferrous citrate, due to during oxidation be difficult to control to, occur in that larger error, mean error exceedes
25%.And using more poisonous and harmful reagent, process is loaded down with trivial details wayward.And this method can directly measure ironic citrate,
Microalgae field is with strong points, sensitivity is high.
When measuring ferrous citrate with National Standard Method reluctantly, because operating process is loaded down with trivial details, ferrous during sample pretreatment
Ferric iron will be oxidized to, the more difficult control of practical measurement, error is larger.And this method directly measures in mixture, particularly
In microalgae nutritive salt during ferric iron content, because process is simple, agents useful for same is less, and the time is shorter, and ferrous iron is tied to greatest extent
Fruit avoids aoxidizing, and can be widely applied to high accuracy scientific experiment and production practices.
Claims (7)
1. in a kind of algae nutritive salt iron concentration assay method, its step includes：
(1) preparing ferric ion concentration is 6 × 10-3The ironic citrate titer of mol/L, is cooled to 18-25 DEG C；
(2) the ironic citrate titer in step (1) is diluted to the dilution of variable concentrations, is recorded using light absorbs ELIASA
Absorbance values at 450nm for the ironic citrate dilution, with A450 mean value as ordinate, to should absorbance iron
Ion concentration is abscissa, draws standard working curve；
(3) measure absorbance at 450nm for the algae nutritive salt sample, according to the standard working curve drawn in step (1),
Calculate the ferric ion concentration in sample；
(4) the actual measurement ferric ion that the initial concentration of the ferric ion in algae nutritive salt sample deducts in step (2) is dense
Degree, is the ferrous ion concentration in algae nutritive salt sample.
2. in algae nutritive salt according to claim 1 iron concentration assay method it is characterised in that：Described step
(2), in, the ferric ion concentration in ironic citrate dilution is 0,0.6 × 10-3mol/L、1.2×10-3mol/L、2.4×
10-3mol/L、4.8×10-3Mol/L and 6 × 10-3mol/L.
3. in algae nutritive salt according to claim 1 iron concentration assay method it is characterised in that：Described algae
The composition of nutritive salt sample is the mixed liquor of ironic citrate and ferrous citrate.
4. in algae nutritive salt according to claim 1 iron concentration assay method it is characterised in that：Described step
(1), in, open-assembly time is less than 3 minutes the ironic citrate titer after preparing in atmosphere.
5. in algae nutritive salt according to claim 1 iron concentration assay method it is characterised in that：Described step
(2), in, during titer dilution, the dilution of employing is anaerobic distilled water.
6. in algae nutritive salt according to claim 1 iron concentration assay method it is characterised in that：Described step
(2), in, mixing in dilution standard liquid can be it is impossible to produce bubble, and Ambient Operating Temperature is less than 25 DEG C.
7. in algae nutritive salt according to claim 1 the assay method of iron concentration it is characterised in that described step
(3) in, before algae nutritive salt sample determination, by sample at 4 DEG C sealing preserve and bubble can not be mixed with, sample is sudden and violent in atmosphere
The dew time is less than 3 minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510056756.2A CN104596965B (en) | 2015-02-03 | 2015-02-03 | Determination method of concentration of iron ion in algae nutrient |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510056756.2A CN104596965B (en) | 2015-02-03 | 2015-02-03 | Determination method of concentration of iron ion in algae nutrient |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104596965A CN104596965A (en) | 2015-05-06 |
| CN104596965B true CN104596965B (en) | 2017-02-22 |
Family
ID=53122886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510056756.2A Active CN104596965B (en) | 2015-02-03 | 2015-02-03 | Determination method of concentration of iron ion in algae nutrient |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104596965B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101782508A (en) * | 2010-02-05 | 2010-07-21 | 中国科学院海洋研究所 | Method for measuring contents of ferrous, ferric iron and total iron in seawater |
| CN103048296A (en) * | 2012-12-19 | 2013-04-17 | 浙江大学 | Method for detecting iron content of chlorella |
| CN103913421A (en) * | 2012-12-28 | 2014-07-09 | 中国科学院沈阳应用生态研究所 | Method for determining water-soluble Fe content of eutrophic lake |
-
2015
- 2015-02-03 CN CN201510056756.2A patent/CN104596965B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101782508A (en) * | 2010-02-05 | 2010-07-21 | 中国科学院海洋研究所 | Method for measuring contents of ferrous, ferric iron and total iron in seawater |
| CN103048296A (en) * | 2012-12-19 | 2013-04-17 | 浙江大学 | Method for detecting iron content of chlorella |
| CN103913421A (en) * | 2012-12-28 | 2014-07-09 | 中国科学院沈阳应用生态研究所 | Method for determining water-soluble Fe content of eutrophic lake |
Non-Patent Citations (1)
| Title |
|---|
| 硅藻土中可溶性铁离子的测定;贾翠莉 等;《啤酒科技》;20021231(第12期);第21-23页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104596965A (en) | 2015-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103323412B (en) | Thiocyanate spectrophotometry method for detecting iron content of high-temperature alloy | |
| CN102375068B (en) | Full-automatic nutrient salt analyzer and analysis method thereof | |
| CN101995383A (en) | Method for measuring copper ion content of solution | |
| CN101334365B (en) | Determination method for chloride ion content of temper rolling liquor for steel plate rolling | |
| CN101846651A (en) | Method for measuring boric acid and borate in cosmetics by microwave digestion -ICP-MS | |
| CN104897766A (en) | Correction method for determination of trace element in sample by isotope dilution mass spectrometry | |
| CN104483280A (en) | Method for rapidly detecting ammonia nitrogen removal rate | |
| CN108107012A (en) | A kind of test reagent combination of total phosphorus in-line analyzer and its method for measuring total phosphorus content in water sample | |
| CN106568816A (en) | Reagent and method for rapidly measuring ammonia nitrogen content of oil refining sewage through electrode method | |
| CN105092496B (en) | The detection method of phosphorus content in a kind of nitridation reinforcing agent | |
| Economou et al. | Determination of boron in water and pharmaceuticals by sequential-injection analysis and fluorimetric detection | |
| CN104614370A (en) | Quick nitrite detection method based on nanogold | |
| CN103645274B (en) | Measure the method for chloride ion content in cold-rolling emulsion | |
| CN108020541A (en) | The method of sulfur content in inductively coupled plasma emission spectrography measure ferrosilicon | |
| CN110174458A (en) | The detection method that lead and total arsenic measure simultaneously in a kind of formulated food additive | |
| Wang et al. | Determination of the speciation of aluminum (III) in natural waters by adsorption stripping voltammetry and complexation with AlIII–solochrome violet RS | |
| CN107664638A (en) | The assay method of W content in a kind of steel | |
| CN103776953A (en) | Determination method of content of cobalt in lithium battery ternary positive electrode material | |
| CN104596965B (en) | Determination method of concentration of iron ion in algae nutrient | |
| CN102539352B (en) | Determination method of cyanogen in thiocyanate | |
| CN102445486A (en) | Analytic method for measuring cobalt element in soft magnetic, elastic and highly elastic alloys | |
| CN109211811B (en) | Detection method of iron blue content | |
| CN108008033A (en) | A kind of method for measuring water nitrite and nitrous acid content | |
| CN103940763A (en) | Method for detection of lead ions in water | |
| CN103940758A (en) | Method for detection of lead ions in water |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |