CN103091314B - Rapid detection method for water-soluble azo dyes in foods - Google Patents
Rapid detection method for water-soluble azo dyes in foods Download PDFInfo
- Publication number
- CN103091314B CN103091314B CN201310015506.5A CN201310015506A CN103091314B CN 103091314 B CN103091314 B CN 103091314B CN 201310015506 A CN201310015506 A CN 201310015506A CN 103091314 B CN103091314 B CN 103091314B
- Authority
- CN
- China
- Prior art keywords
- azo dyes
- soluble azo
- color
- quick
- polyamide column
- 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.)
- Expired - Fee Related
Links
Abstract
The invention provides a rapid detection method for water-soluble azo dyes in foods. The method comprises the steps of (A), sample extraction; (B), polyamide column concentration and purification; (C), elution of pigments; and (D) qualitative detection. According to the rapid detection method, the rapid screening can be timely and effectively carried out on suspected samples, the method is independent of large-scale instruments and equipments, and lawbreakers can be harshly attacked within the shortest time; and besides, the rapid detection method further has the advantages of short detection time, wide applicable range, high detection accuracy, low detection limit, strong anti-interference capacity and the like.
Description
Technical field
The present invention relates to field of detection of food safety, particularly relate to soluble azo dyes method for quick in a kind of food.
Background technology
The pigment that domestic approval uses mainly contains natural colouring matter and synthetic dyestuff two class, wherein allows the synthetic dyestuff used to comprise the low toxicity azo dyes such as famille rose, sunset yellow and amaranth.Reasonably use food coloring that food color can be made bright-coloured tempting, make us appetite good, but under the ordering about of interests, the even illegal use industrial dye of illegal retailer's over range abuse synthetic dyestuff, constantly food safety affair such as outburst " tonyred ", " dyeing steamed bun " etc.At present, less to the method for quick forbidding, limit the use of azo dyes and industrial pigment in food both at home and abroad, a lot of pigment uses non-compliant food to be strangled at production field, therefore sets up relevant method for quick to closing necessity.
In prior art, chromatography, spectral absorption scheduling theory Foundation qualitative based on colorability about the research major part of azo dyes Fast Measurement in food, for be fat-soluble azo dyes, detection method mainly comprises:
1) with fat-soluble pigment in the organic solvent extracting sample thiefs such as thiacyclohexane, potassium permanganate oxidation natural colouring matter under acid condition, reducing agent hydroxylamine hydrochloride removing excessive oxidant, and then can keep as positive judgment basis according to organic layer color before and after process;
2) pure water extraction sample pigment, adsorbs under the adsorbent sheet acid condition that polyamide or wool are made, and with the stripping of ammoniacal liquor ethanol after pure water purification, the colour developing web in half made with wood-fibred, according to whether developing the color as the positive foundation judged;
3) after textile sample being carried out reduction treatment with reference to GB/T 17592-2006, methyl tertiary butyl ether extracts decolouring, more at room temperature with nitrous acid diazotising-coupling colour developing, judges according to carrying out the positive with or without color.
For detection method 1), in existing technology (number of patent application 200710027591.1), because acid potassium permanganate has strong oxidizing property, can react to the organic matter extracted from sample, may coloring matter be generated thus cause interference; After table 2 display adds target actual sample reaction treatment there is significant change in organic layer color, is different from table 1 blank and adds target experimental result.Above experimental result may be that three kinds of reasons cause, one is may there is the halfway side reaction of oxidation in oxidizing process to generate coloring matter, change the color of organic layer, two is can not enter organic layer colour developing by oxidized coloring matter in sample, and three is that in organic layer, organic matter is caused lighter before and after mark-on sample treatment by exhaustive oxidation.The method did not both carry out interference confirmatory experiment to fat-soluble natural pigment, did not also carry out contrasting with the false positive rate of instrumental method verifying, more the experimental phenomena of his-and-hers watches 2 does not illustrate its reason.Thus the method is in application process, only according to organic layer before treatment after with or without color as judgment basis may exist false positive erroneous judgement situation, be unfavorable for the whether illegal use fat-soluble pigment of accurate qualitative sample.
For detection method 2), in existing technology (number of patent application 20081002995.9), the polyamide that adsorbent sheet is used or wool yield less, limited to the plate carrying capacity of pigment, be unfavorable for enrichment and colour developing when sample synthetic dyestuff content is low, easily fail to judge.Pigment is after adsorbent sheet enrichment, and the natural colouring matter (as curcumin, Monascus color etc.) that partial adsorbates ability is strong can not reach the object removed completely only according to pure water, finally can affect the positive result judged.
For detection method 3), in existing technology (number of patent application 201110350255.7), the quick colour-developing test operating procedure of textile is complicated, and generally will carry out at 1-5 DEG C due to diazotising-coupling reaction, under room temperature, nitrous acid and diazonium intermediate easily decompose, be unfavorable for follow-up chromogenic reaction, the situation of failing to judge may be there is.
Therefore, there is the interference being easily disturbed thing in existing detection method, poor accuracy, complicated operation, and detection time is grown, need the shortcomings such as complex analyses instrument, and cannot detect fast for soluble azo dyes.
Summary of the invention
For solving problems of the prior art, inventor against expectation finds, the pigment in sample is extracted by ammonia spirit, also purify with the mixed liquor of methyl alcohol and acetic acid through polyamide column enrichment, after the mixed liquor wash-out separating water-soluble azo dyes of ethanol and ammoniacal liquor, then the fast qualitative detection of the soluble azo dyes that decolours by zinc powder and ammonium acetate reduction system, can carry out.In food provided by the invention, soluble azo dyes method for quick is by Site Detection, can carry out the rapid screening of suspicious specimen timely and effectively, not rely on large-scale instrument and equipment, can give lawless person severe strike within the shortest time; In addition, it is short that the present invention also has detection time, applied widely, and detection accuracy is high, and detection limit is low, and background interference is little, the advantages such as antijamming capability is strong.
Soluble azo dyes method for quick in a kind of food, comprises the steps:
A) sample extraction: get testing sample, adds dilute ammonia solution, shakes up in water-bath, gets supernatant after leaving standstill, and adds citric acid and adjusts pH to 5 ~ 7, obtain sample extracting solution in this supernatant;
B) polyamide column enrichment and purification: be transferred in polyamide column by described sample extracting solution, separating filtrate, makes pigment be enriched on polyamide column, and the mixed liquor getting methyl alcohol and acetic acid washs this polyamide column;
C) wash-out of pigment: polyamide column described in the mixed liquor wash-out getting ethanol and ammoniacal liquor, collects eluent, the color of the color of eluent and standard comparison liquid is compared;
D) qualitative detection: if the color of eluent is darker than the color of standard comparison liquid, described eluent equivalent is divided into control group and test set, ammonium acetate solution and 0.09 ~ 0.11g zinc powder of 0.5 ~ 3 mL is added in this test set, after shaking up, filtering, compare with control group, observe this test set color whether to take off, if color fade, then judge that testing result is as the positive.
Adopt technique scheme, the present invention can carry out the rapid screening of suspicious specimen timely and effectively, does not rely on large-scale instrument and equipment, can give lawless person severe strike within the shortest time; In addition, also have detection time short, applied widely, detection accuracy is high, and detection limit is low, and background interference is little, the advantages such as antijamming capability is strong.
Cleaning Principle of the present invention is: soluble azo dyes retains in acid condition and is enriched in polyamide column, under alkali condition, from polyamide column, wash-out is separated, by the synergy of zinc powder and ammonium acetate, there is reduction reaction rapidly at ambient temperature in gained eluent, if color fade, then judge that testing result is as the positive.By enrichment and the purification of polyamide column, effectively can get rid of the interference of the chaff interferences such as natural colouring matter, can be widely used in that the lemon yellow in field quick detection food, sunset yellow, famille rose, light blue, amaranth, temptation are red, the soluble azo dyes such as Acid Orange II, acid scarlet, Methanil Yellow G.
Zinc powder and ammonium acetate act synergistically, and the reaction equation of reduction lemon yellow pigment is as follows:
As a further improvement on the present invention, the pH of described weak aqua ammonia is 9 ~ 10.
As a further improvement on the present invention, described soluble azo dyes comprises that lemon yellow, sunset yellow, famille rose, light blue, amaranth, temptation are red, Acid Orange II, acid scarlet and Methanil Yellow G.
As a further improvement on the present invention, described ammonium acetate solution is saturated acetic acid ammonium salt solution; Saturated acetic acid ammonium salt solution is conducive to the carrying out reacted, and forms optimum reaction condition.
As a further improvement on the present invention, described polyamide column adopts the chromatographic column being filled with 0.2 ~ 0.3g Silon, and the particle diameter of described Silon is 200 ~ 300 orders.
As a further improvement on the present invention, in the mixed liquor of described methyl alcohol and acetic acid, the volume ratio of methyl alcohol and acetic acid is 6:4.
As a further improvement on the present invention, in the mixed liquor of described ethanol and ammoniacal liquor, the volume ratio of ethanol and ammoniacal liquor is 7:3, and wherein ammoniacal liquor is mixed with the volume ratio of 2:1 by concentrated ammonia liquor and water and obtained.
As a further improvement on the present invention, the addition of described zinc powder is 0.1g.The addition of zinc powder is most important for the accuracy detected, if addition is too many, due to the color that zinc itself has, can produce color interference, thus affect detection accuracy; If addition very little, then may cause reaction not exclusively, thus affect detection accuracy.
Compared with prior art, the invention has the beneficial effects as follows: the pre-treatment step of the present invention to GB/T5009.35-2003 improves, and adopt zinc powder and ammonium acetate system synergy, fast restore soluble azo dyes under room temperature, not only substantially reduce pre-treatment time and detection time, the rapid screening of suspicious specimen can be carried out timely and effectively, do not rely on large-scale instrument and equipment, lawless person can be given severe strike within the shortest time; In addition, it is short that the present invention also has detection time, applied widely, and the result measured with GB/T5009.35-2003 is consistent, and detection accuracy is high, and detection limit is low, and background interference is little, the advantages such as antijamming capability is strong.
Accompanying drawing explanation
Fig. 1 is halogen meat products positive eluent and qualitative results schematic diagram thereof.
Fig. 2 is eluent and the qualitative results schematic diagram thereof of part mark-on sample, and wherein 1 is carmine, and 2 is light blue, and 3 is amaranth.
Detailed description of the invention
Below in conjunction with drawings and Examples, the present invention is described in further details.
Preparation of reagents method in the embodiment of the present invention is as follows:
Dilute ammonia solution: get a certain amount of distilled water, adds concentrated ammonia liquor and regulates pH value of solution=9 ~ 10;
Citric acid solution: get 20g citric acid solid and be dissolved in 70ml distilled water, be transferred to 100ml volumetric flask, be settled to scale;
The mixed liquor of methyl alcohol and acetic acid: methyl alcohol and acetic acid are with 6:4(v/v) mix and obtain;
In the mixed liquor of ethanol and ammoniacal liquor, the volume ratio of ethanol and ammoniacal liquor is 7:3, and wherein ammoniacal liquor is mixed with the volume ratio of 2:1 by concentrated ammonia liquor and water and obtained;
Saturated acetic acid ammonium salt solution: get a certain amount of ammonium acetate solid, add a small amount of distilled water, supersonic oscillations can not be dissolved to solid;
Polyamide column: the chromatographic column being filled with 0.2-0.3g Silon; Silon grade is planar chromatography use, 200 ~ 300 orders;
Standard comparison liquid series: formed by standard liquid serial dilution, lemon yellow 1.0 mg/kg, sunset yellow 1.0 mg/kg, carmine 1.0 mg/kg, light blue 1.0 mg/kg, amaranth 1.0 mg/kg, lure red 1.0 mg/kg, Acid Orange II 1.0 mg/kg, acid scarlet 1.2 mg/kg, Methanil Yellow G 1.0 mg/kg.
the detection of soluble azo dyes in embodiment one food.
Sample thief 3.0g, adds dilute ammonia solution 15mL, shakes up in warm water water-bath, gets supernatant after leaving standstill, and adds citric acid solution and adjusts pH to 5.8, obtain sample extracting solution in this supernatant; Be transferred in polyamide column by described sample extracting solution, separating filtrate, make pigment be enriched on polyamide column, the mixed liquor getting methyl alcohol and acetic acid washs this polyamide column 2 ~ 3 times, each 3mL; The polyamide column of the mixed liquor wash-out getting ethanol and ammoniacal liquor again after the mixed liquor washing of methyl alcohol and acetic acid 2 ~ 3 times, each 2mL, collects eluent; Described eluent equivalent is divided into control group and test set, in this test set, adds saturated acetic acid ammonium salt solution and the 0.1g zinc powder of 1mL, after shaking up 10 ~ 20 seconds, filter, compare with control group, observe this test set color and whether take off, if color fade, then judge that testing result is as the positive.If the color of eluent is more shallow than the color of standard comparison liquid, then testing result is invalid.
Above-mentioned sample comprises Flour product, halogen meat products, bean-curd product three class, totally 85 samples, the detection method provided by the present embodiment detects, and result shows: detect positive 8 parts, positive rate is 9.4%, and it is as shown in table 1 that all kinds of Sample Positive detects statistics.Fig. 1 is halogen meat products positive eluent and qualitative results schematic diagram thereof.As can be seen from Figure 1, colour generation eluent (left side) is after zinc powder and ammonium acetate reduction, and the color fade of solution, detects result for positive.
the detection limit of soluble azo dyes in embodiment two food.
Get Flour product sample, add the lemon yellow standard liquid of different volumes respectively and shake up, after detecting by the detection method in embodiment one, by dense acetic acid adjust ph to neutral, distilled water is settled to 10mL, observes the solution colour depth, filters, detect mark-on solution actual concentrations by GB 5009.35-2003, do blank sample contrast simultaneously.
Sunset yellow, famille rose, light blue, amaranth, red, Acid Orange II, acid scarlet, Methanil Yellow G the detection limit experiment of temptation operate with lemon yellow.Mark-on solution theory concentration and the actual detectable concentration after this method process are in table 2.
Fig. 2 is eluent and the qualitative results schematic diagram thereof of part mark-on sample, and wherein 1 is carmine, and 2 is light blue, and 3 is amaranth.According to the shade degree of Fig. 2 mark-on solution, consider that zinc powder and ammonium acetate solution are adding existence absorption and diluting effect in solution processes, the qualitative detection limit of Flour product, halogen meat, bean-curd product is defined as by the present invention: lemon yellow 1.0 mg/kg, sunset yellow 1.0 mg/kg, carmine 1.0 mg/kg, light blue 1.0 mg/kg, amaranth 1.0 mg/kg, lures red 1.0 mg/kg, Acid Orange II 1.0 mg/kg, acid scarlet 1.2 mg/kg, Methanil Yellow G 1.0 mg/kg.
Standard comparison liquid refers to the pigment standard liquid of detection limit concentration preparation.Because the present invention is the qualitative method that view-based access control model judges, the eluent more shallow for color need determine whether under detection limit of the present invention by standard comparison liquid, reduces the erroneous judgement that may produce because of the adsorption bleaching of zinc powder.The color of eluent is darker than corresponding standard comparison liquid color, is " if color fade, then judging that testing result is as the positive " whether effective prerequisite of this conclusion.If the color of eluent is more shallow than corresponding standard comparison liquid color, then testing result is invalid.
embodiment three sample detects positive coincidence rate.
Detected by the GB/T5009.35-2003 mensuration of synthetic coloring matter " in the food " by embodiment one 85 sample, the testing result of testing result and the inventive method compared, calculate positive coincidence rate, result is as shown in table 3.As shown in Table 3, the inventive method in the accuracy of positive rate with national standard method there was no significant difference.
embodiment four natural colouring matter is to the interference of the inventive method.
With riboflavin, curcumin, Monascus color three kinds of natural colouring matters for subjects, get its standard liquid 0.50ml respectively in 10ml colorimetric cylinder, add water and be settled to scale, the detection method in embodiment one detects, and experimental result is as shown in table 4.As known from Table 4, by methanol-acetic acid eluant solution in the experimental procedure that riboflavin, curcumin, Monascus color purify at polyamide column, interference effect can not be there is to the qualitative of acid azopigment.
In sum, the inventive method can meet the quick detection of soluble azo dyes in food, has detection time short, applied widely, the result measured with GB/T5009.35-2003 is consistent, and detection accuracy is high, detection limit is low, and background interference is little, the advantages such as antijamming capability is strong.If be positive through the inventive method inspection, then this sample is just very likely illegal uses the soluble azo dyes forbidden or limit the use of.
Above content is in conjunction with concrete preferred embodiment further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, some simple deduction or replace can also be made, all should be considered as belonging to protection scope of the present invention.
Claims (7)
1. a soluble azo dyes method for quick in food, is characterized in that: comprise the steps:
A) sample extraction: get testing sample, adds the dilute ammonia solution that pH is 9-10, shakes up in water-bath, gets supernatant after leaving standstill, and adds citric acid and adjusts pH to 5-7, obtain sample extracting solution in this supernatant;
B) polyamide column enrichment and purification: be transferred in polyamide column by described sample extracting solution, separating filtrate, makes pigment be enriched on polyamide column, and the mixed liquor getting methyl alcohol and acetic acid washs this polyamide column;
C) wash-out of pigment: polyamide column described in the mixed liquor wash-out getting ethanol and ammoniacal liquor, collects eluent, the color of the color of eluent and standard comparison liquid is compared;
D) qualitative detection: if the color of eluent is darker than the color of standard comparison liquid, described eluent equivalent is divided into control group and test set, ammonium acetate solution and the 0.09-0.11g zinc powder of 0.5-3 ml is added in this test set, after shaking up, filtering, compare with control group, observe this test set color whether to take off, if color fade, then judge that testing result is as the positive.
2. soluble azo dyes method for quick in food according to claim 1, is characterized in that: described soluble azo dyes comprises that lemon yellow, sunset yellow, famille rose, light blue, amaranth, temptation are red, Acid Orange II, acid scarlet and Methanil Yellow G.
3. soluble azo dyes method for quick in food according to claim 1, is characterized in that: described ammonium acetate solution is saturated acetic acid ammonium salt solution.
4. soluble azo dyes method for quick in food according to claim 1, is characterized in that: described polyamide column adopts the chromatographic column being filled with 0.2-0.3g Silon, and the particle diameter of described Silon is 200-300 order.
5. soluble azo dyes method for quick in food according to any one of claim 1 to 4, is characterized in that: in the mixed liquor of described methyl alcohol and acetic acid, and the volume ratio of methyl alcohol and acetic acid is 6:4.
6. soluble azo dyes method for quick in food according to any one of claim 1 to 4, it is characterized in that: in the mixed liquor of described ethanol and ammoniacal liquor, the volume ratio of ethanol and ammoniacal liquor is 7:3, and wherein ammoniacal liquor is mixed with the volume ratio of 2:1 by concentrated ammonia liquor and water and obtained.
7. soluble azo dyes method for quick in the food according to any one of claim 1, is characterized in that: the addition of described zinc powder is 0.1g.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310015506.5A CN103091314B (en) | 2013-01-16 | 2013-01-16 | Rapid detection method for water-soluble azo dyes in foods |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310015506.5A CN103091314B (en) | 2013-01-16 | 2013-01-16 | Rapid detection method for water-soluble azo dyes in foods |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103091314A CN103091314A (en) | 2013-05-08 |
| CN103091314B true CN103091314B (en) | 2015-03-25 |
Family
ID=48204148
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310015506.5A Expired - Fee Related CN103091314B (en) | 2013-01-16 | 2013-01-16 | Rapid detection method for water-soluble azo dyes in foods |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103091314B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104655752B (en) * | 2015-02-10 | 2018-07-03 | 广西中烟工业有限责任公司 | The assay method of Acid Brilliant Scarlet GR in a kind of paper food packaging materials |
| CN105115965A (en) * | 2015-07-27 | 2015-12-02 | 南昌大学 | Soft drink synthetic pigment fast detection method and kit |
| CN105277552B (en) * | 2015-11-18 | 2018-10-30 | 福州大学 | A kind of device and its application method for azo colouring agent on-line checking |
| CN105588832A (en) * | 2015-12-10 | 2016-05-18 | 厦门华厦学院 | Device and method for rapidly detecting basic orange, acid orange and basic tender yellow |
| CN106841476B (en) * | 2017-04-19 | 2019-10-18 | 广东出入境检验检疫局检验检疫技术中心 | A kind of method and its sample-pretreating method detecting synthetic coloring matter |
| CN107703129B (en) * | 2017-09-08 | 2020-07-03 | 瓮福达州化工有限责任公司 | Method for detecting chromatic aberration of colorant |
| CN108181251B (en) * | 2018-01-12 | 2020-08-18 | 浙江工商大学 | Lemon yellow detection method |
| CN112213437B (en) * | 2020-09-28 | 2021-04-23 | 诺安实力可商品检验（青岛）有限公司 | HPLC (high Performance liquid chromatography) and LC-MS/MS (liquid chromatography-Mass Spectrometry/Mass Spectrometry) detection method for orange B in pet food |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5922530A (en) * | 1994-09-08 | 1999-07-13 | Lifescan, Inc. | Stable coupling dye for photometric determination of analytes |
| CN102507561B (en) * | 2011-11-08 | 2013-03-27 | 山东出入境检验检疫局检验检疫技术中心 | Rapid detection kit and detection method of forbidden azo dyes in dyed textiles |
| CN102636592B (en) * | 2012-05-10 | 2014-02-05 | 重庆出入境检验检疫局检验检疫技术中心 | Method for simultaneous determination of plurality of synthetic pigments in hot pot flavorings |
-
2013
- 2013-01-16 CN CN201310015506.5A patent/CN103091314B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN103091314A (en) | 2013-05-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103091314B (en) | Rapid detection method for water-soluble azo dyes in foods | |
| CN105255481B (en) | A kind of phenanthro- imidazoles coumarin pair fluorophor ratio fluorescent molecular probe and its synthesis and using method for iron ion detection | |
| Schmall et al. | Determination of ascorbic acid by new colorimetric reaction | |
| Pourreza et al. | Indirect cloud point extraction and spectrophotometric determination of nitrite in water and meat products | |
| Kirschbaum et al. | Development and evaluation of an HPLC-DAD method for determination of synthetic food colorants | |
| CN104142321A (en) | Method for fast detecting surface enhancing Raman spectrums of pesticide residues in tea leaves | |
| Shabani et al. | Indirect spectrophotometric determination of ultra trace amounts of selenium based on dispersive liquid–liquid microextraction–solidified floating organic drop | |
| Liu et al. | A colorimetric, ratiometric, and fluorescent cobalt (II) chemosensor based on mixed organic ligands | |
| CN103616380A (en) | Reagent and method for rapidly detecting formaldehyde in foods | |
| CN104007107A (en) | Detection method for trace lead in agricultural products | |
| CN107064401B (en) | A method of it quickly detects simultaneously and illegally adds ten kinds of pigments in beverage | |
| CN107167532A (en) | A kind of method of food additives in use high performance liquid chromatography test food | |
| Zhu et al. | Selective colorimetric and fluorescent quenching determination of uranyl ion via its complexation with curcumin | |
| CN104897665A (en) | One-step color-development screening method for banned azo-dye in dyeing textiles | |
| CN107024461A (en) | A kind of method of the double probe rapid detection of nitrite in food of fluorescence/colorimetric | |
| Clark | Cobalt determination in soils and rocks with 2-nitroso-1-naphthol | |
| Ensafi et al. | Kinetic spectrophotometric determination of low levels of nitrite by catalytic reaction between pyrogallol red and bromate | |
| Nouroozi et al. | Flow injection kinetic spectrophotometric method for the determination of trace amounts of nitrite | |
| CN105628817A (en) | Method for distinguishing natural indigo blue and synthetic indigo blue dyed fabrics | |
| CN106370649A (en) | Method for quickly detecting whether nitrite content of processing meat product exceeds standard or not | |
| Guest | Determination of copper in metallurgical analysis | |
| CN102841090B (en) | Gelatin and detecting method for hexavalent chromium in products thereof | |
| Shpigun et al. | Kinetic separation in flow injection spectrophotometry: simultaneous determination of copper and zinc in a single run | |
| CN100494995C (en) | Leather Cr6+ automatic analysis method | |
| Liu et al. | Simultaneous determination of multicomponents by flow injection analysis: determination of copper and zinc in serum by using zincon as colouring reagent |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150325 Termination date: 20200116 |