CN106483157A - The determination method of total chlorine in a kind of doctor solution - Google Patents
The determination method of total chlorine in a kind of doctor solution Download PDFInfo
- Publication number
- CN106483157A CN106483157A CN201610881791.2A CN201610881791A CN106483157A CN 106483157 A CN106483157 A CN 106483157A CN 201610881791 A CN201610881791 A CN 201610881791A CN 106483157 A CN106483157 A CN 106483157A
- Authority
- CN
- China
- Prior art keywords
- doctor solution
- chloride
- standard specimen
- sample
- total chlorine
- 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.)
- Granted
Links
Classifications
-
- 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
- G01N23/22—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 measuring secondary emission from the material
- G01N23/223—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 measuring secondary emission from the material by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The present invention relates in a kind of doctor solution total chlorine determination method, doctor solution is pre-processed using physical method, prepares sample；Using the fluorescence intensity of the chloride series standard specimen of xrf analysis instrument measure, the chloride content that sets up in chloride series standard specimen and the corresponding relation of fluorescence intensity, the calibration curve of chloride serial standard specimen is drawn, and thus calculates the content of total chlorine in doctor solution.The inventive method is on the basis of pre-processing to doctor solution, eliminate interference of the complicated ions to measurement result in colourity, turbidity, suspension, doctor solution, using the content of total chlorine in fluorescence spectrum method for measuring doctor solution sample, have the advantages that reproducible, accuracy high, workable, determine quick.
Description
Technical field
The present invention relates in a kind of doctor solution total chlorine determination method, belong to petroleum chemical industry detection technique field, especially relate to
And a kind of method that utilization X fluorescence spectrum method determines chloride content.
Background technology
High sulfur Gas Fields are mixed with the medicaments such as foam inhibiting agent, corrosion inhibiter during production natural gas, containing free water and solid
Impurity, while produce natural gas to contain the acidic components such as hydrogen sulfide, carbon dioxide and organic sulfur.Unstripped gas needs to purify, and uses
Doctor solution carries out depickling process, absorbs the acidic materials such as hydrogen sulfide in unstripped gas, carbon dioxide.
Salt is generated after doctor solution and acidic components reaction, mainly have oxalates, formates, thiosulfate etc..Desulfurization
Liquid is by molten sulphur agent, antisludging agent and the pipe in unstripped gas due to carrying during drilling well, underground work, gas production, pipelined etc.
The various impurity effects such as product after line corrosion are degraded, and cause that doctor solution colourity is higher, turbidity is bigger than normal, suspension content liter
Height, causes the composition of doctor solution sufficiently complex, it is impossible to chlorinity in Accurate Determining doctor solution.Chlorine element in doctor solution is derived from
Unstripped gas, and have cumulative effect, exist with various ways such as chlorion, free chlorine, combined chlorine and organochlorines, various forms of
Chlorine element can produce HCl and Cl by conversion, muriatic hydrolysis under suitable condition2, desulphurization plant burn into can be caused
Reduce desulfurized effect.Want the harm for controlling such case to cause, first have to carry out accurately the content of chlorine element in doctor solution
Measure, in doctor solution, chlorinity is an important index.
Determine in national standard and professional standard at present chloride ion content in water body method have following several：
(1) Moire technique：Containing Cl-Neutrality or weakly alkaline solution in, with K2CrO4Make indicator, use AgNO3Standard is molten
Drop determines Cl-.As the solubility of AgCl compares Ag2CrO4Little, according to fractional precipitation principle, realize separating out AgCl white in solution
Precipitation.After AgCl quantitative deposition is complete, slightly excessive Ag+With K2CrO4Generate bolarious Ag2CrO4Precipitation, so as to indicate end
The arrival of point.
(2) Fo Erhadefa：In acid medium, with test solution of the ammonium thiocyanate standard liquid direct titration containing Ag+, sulphur is treated
Complete, the slightly excessive SCN of silver cyanate precipitation-With Fe3+Reaction generates red complex ion, indicates to have reached titration end-point.Using returning
Titration can determine Cl-.Excess nitric acid silver titer, Cl are added-After generating silver nitride precipitation, then it is surplus to return drop with ammonium thiocyanate
Remaining Ag+.
Method (1), (2) judge chemical equivalent point by color, it is adaptable to which the water quality such as recirculated water, cooling water, surface water is turbid
The less sample determination of degree less, hydrogen sulfide of relatively low, colourity etc. impurity interference, be not suitable for determining containing a large amount of hydrogen sulfide and its
The water quality of its impurity.Therefore the method cannot be used for determining the chlorinity in doctor solution.
(3) automatic potentiometric titration：With silver electrode as electrode is responded, with chlorion in silver nitrate solution titration water, wait and work as
During point, potential break is produced, terminal current potential is determined with this, this terminal potential value locked on instrument, by curve equation meter
The content of chlorion in sample is calculated, so as to complete automatically analyzing for sample.
(4) chromatography of ions：The chlorion in sample is carried out adsorbing, is separated by anion separation column, by producing
Peak height and the contrasting detection of peak area and calibration curve go out the concrete content of the chlorion contained in sample.
Method (3), (4) can only be detected for there is chlorine element present in water in the form of an ion, without combined chlorine
Detectability with organochlorine.Chromatography of ions has strict demand to impurity content, and content of organics is less than 10%, more than this
Standard, chromatographic column will be contaminated；In doctor solution, content of organics is typically 40% or so, it is impossible to meet the requirement of analysis.
Content of the invention
The purpose of the present invention is intended to the defect for overcoming above-mentioned prior art to affect certainty of measurement due to doctor solution complicated component,
The assay method that a kind of utilization X fluorescence spectrum method determines chloride content in high sulfur-containing natural gas doctor solution is provided.
After the present invention is excited by x-ray bombardment based on chlorine element, the fluorescence with specific wavelength is produced, is divided using X-fluorescence
Analyzer measure doctor solution sample and the fluorescence intensity of chloride series standard specimen, the chloride content that sets up in chloride series standard specimen and fluorescence
The corresponding relation of intensity, draws the calibration curve of chloride series standard specimen, and thus calculates the content of total chlorine in doctor solution.
The present invention is realized by following steps：
1 sample preparation
1.1 remove oarse-grained suspension in doctor solution sample using filtration method；
1.2 suspensions for removing doctor solution sample small particles using centrifugal process；
1.3 remove the hydrogen sulfide in doctor solution sample using heating；
1.4 carry out homogenize process using ultrasound bath heating to doctor solution sample；
1.5 are placed in the doctor solution sample after homogenize process in the closed container of light-permeable；
2 Specification Curve of Increasings
2.1 using desulfurizing agent stoste and the chloride series standard specimen of chloride chemistry preparation of reagents, and the chloride series standard specimen is by containing
The desulfurizing agent solution composition of variable concentrations chlorine；
2.2 choice experiment conditions：The parameters such as detector voltage, excitation voltage, excitation current, minimum vacuum degree are set；
2.3 utilize X- fluorescent spectrometry, determine the fluorescence intensity of chloride series standard specimen, set up total in chloride series standard specimen
Chlorinity and the corresponding relation of fluorescence intensity, draw the calibration curve of chloride series standard specimen；
The measure of 3 samples
3.1 utilize X- fluorescent spectrometry, determine the fluorescence of total chlorine in the doctor solution sample being placed in light-permeable closed container
Intensity；
3.2 calibration curves for utilizing chloride series standard specimen, calculate the content of total chlorine in doctor solution sample.
The inventive method eliminates colourity, turbidity, suspension, doctor solution multiple on the basis of pre-processing to doctor solution
Interference of the heteroion to measurement result, using the chloride content in fluorescence spectrum method for measuring doctor solution sample, with reproducible,
Accuracy is high, determine quick, workable advantage.
Description of the drawings
The calibration curve of the chloride series standard specimen of Fig. 1.
Specific embodiment
The present invention is described further with MDEA (N- metil-diethanolamine) doctor solution as example.
Embodiment
In the doctor solution of the present invention, the determination method of total chlorine, comprises the following steps：
1 sample preparation
1.1 filter
Using Medium speed filter paper, in slowly filtering doctor solution to conical flask under the stirring of glass bar, doctor solution is filtered
In bulky grain suspension；
1.2 centrifugation
Centrifugally operated is carried out to the doctor solution of step 1.1 using supercentrifuge, filter impact doctor solution turbidity, colourity
Molecule；
1.3 heating
80mL materials in beaker, doctor solution is heated using electricity pottery stove, 80 DEG C of design temperature, leads in closed
Carry out in wind cabinet.During heating operation, experimenter will carry out hydrogen sulfide protection, using gas mask or wear positive-pressure type
Air respiratorresuscitator, while place concentration of hydrogen sulfide detector respectively inside and outside vent cabinet；
1.4 homogeneous
Homogenize process are carried out to the doctor solution after step 1.3 process using ultrasound bath；
The preparation of 1.5 samples
Select circular sample pond, internal diameter 36mm.The doctor solution after homogenizing is pipetted to sample cell with suction pipe or liquid-transfering gun
To graduation mark, the height of graduation mark to specimen cup bottom is more than 15mm, polyester film in tiling, the sample of formation enclosed package shaping
Product, observe sample film, and the analysis face of sample can not have pore, precipitate.Overlay film work be necessarily required to accomplish smooth, do not have
Dust, without fold, guarantee not affect light path to irradiate；
2 Specification Curve of Increasings
The preparation of 2.1 standard liquids
2.1.1 the preparation of solvent：The desulfurization solvent of selection is formulated with distilled water by desulfurizing agent MDEA, and proportioning is MDEA
: distilled water=1: 1；
2.1.2 the composition of conventional chloride standard liquid solute is selected：NaCl∶CaCl2∶MgCl2=70%: 20%: 10%；
2.1.3 chloride series standard liquid is prepared：
6 chloride series standard specimens are prepared, its chloride content is respectively 0ppm, 100ppm, 250ppm, 500ppm,
1000ppm, 2000ppm；
2.2 choice experiment conditions：Detector voltage 2.01KV, excitation voltage 50KV, excitation current 1.0mA, operating temperature
40 DEG C, analysis time 300S, minimum vacuum degree 10；
2.3 draw calibration curve：Using X- fluorescence analyser, measure 6 chloride series standard specimens from low to high in order, lead to
The fluorescence intensity of chloride series standard specimen and the standard value of chloride series standard specimen is crossed, with intensity as ordinate, is fitted shown in Fig. 1
Chloride series standard specimen calibration curve, coefficient R=0.9999, regression equation are y=5.5249x；
1 calibration curve measurement result of table
| Sample | Standard value (mg/L) | Intensity cps | Measured value (mg/L) | Deviation (mg/L) |
| 1# | 0 | 0.5667 | 0.87 | 0.87 |
| 2# | 100 | 19.5867 | 106.54 | 6.54 |
| 3# | 250 | 46.7467 | 257.43 | 7.43 |
| 4# | 500 | 91.5734 | 506.46 | 6.46 |
| 5# | 1000 | 180.9900 | 1003.17 | 3.17 |
| 6# | 2000 | 361.4534 | 2005.80 | 5.80 |
The measure of 3 samples
Select the experiment condition described in 2.2 to be measured doctor solution sample prepared by step 1 using fluorescent spectrometry, survey
The fluorescence intensity that makes；Using the calibration curve of chloride series standard specimen shown in Fig. 1, the content of total chlorine in doctor solution sample is calculated；
The 4 analysis method degrees of accuracy are detected
The recovery of standard addition of 4.1 doctor solution samples
Be separately added into different amounts of chloride in doctor solution, determine the content of total chlorine in doctor solution sample, and calculate plus
The mark rate of recovery, is as a result shown in as table 2.The rate of recovery of total chlorine illustrate that measurement result is reliable and stable, complexity between 95%～105%
Ion measurement result is not made a significant impact, method is accurately credible；
The recovery of standard addition of 2 doctor solution sample of table
| Sample ID | 1# | 2# | 3# |
| Measured value mg/L | 98.6 | 488.7 | 293.4 |
| Theoretical value mg/L | 100.2 | 499.7 | 300.9 |
| The rate of recovery, % | 98.3 | 97.8 | 97.5 |
The repeatability measure of 4.2 doctor solution samples
3 groups of testing sample, replication 5 times is selected, standard deviation is less than 3%, repeatability is preferably.Measurement result such as table 3
Shown：
3 replica test measurement data table of table
| Sample ID | 4# | 5# | 6# |
| 1 measurement result, mg/L | 963.8 | 236.56 | 5035 |
| 2 measurement results, mg/L | 965.46 | 235.84 | 5126 |
| 3 measurement results, mg/L | 979.64 | 237.28 | 5047 |
| 4 measurement results, mg/L | 985.55 | 237.11 | 5004 |
| 5 measurement results, mg/L | 969.45 | 235.98 | 5053 |
| Average, mg/L | 972.782 | 236.554 | 5051.2 |
| Relative standard deviation, % | 0.86651 | 0.24471 | 0.990301 |
Contrast between 4.3 different measuring methods
Alterative titration method and the chromatography of ions are contrasted with this method respectively
(1) selection standard sample is contrasted with X- fluorescence chlorine analytic approach using titration and the chromatography of ions, determines knot
Fruit is as shown in table 4：
Measurement result contrast table of the different analysis method of table 4 to chloride series standard specimen
The sample of selective sweetening liquid is contrasted with X- fluorescence chlorine analytic approach using titration and the chromatography of ions, determines knot
Fruit as shown in table 5, is significantly less than X- fluorescence chlorine assay value for doctor solution sample using titration, and there is repeatability
Poor problem, test data do not have reliability.
Different measurement result contrast tables of the analysis method to doctor solution sample of table 5
Claims (2)
1. in a kind of doctor solution total chlorine determination method, it is characterised in that：Doctor solution sample and chloride is determined using xrf analysis instrument
The fluorescence intensity of serial standard specimen, the chloride content that sets up in chloride series standard specimen and the corresponding relation of fluorescence intensity, draw chloride
The calibration curve of serial standard specimen, determines the content of total chlorine in doctor solution.
2. in a kind of doctor solution according to claim 1 total chlorine determination method, it is characterized in that：Comprise the following steps：
First step sample preparation：
(1) oarse-grained suspension in doctor solution sample is removed using filtration method；
(2) suspension of doctor solution sample small particles is removed using centrifugal process；
(3) trace hydrogen sulfide in doctor solution sample is removed using heating；
(4) homogenize process are carried out to doctor solution sample using ultrasound bath heating；
(5) the doctor solution sample after homogenize process is placed in the closed container of light-permeable；
Second step Specification Curve of Increasing：
(1) using desulfurizing agent stoste and the chloride series standard specimen of chloride chemistry preparation of reagents, the chloride series standard specimen is by containing difference
The desulfurizing agent solution composition of concentration chlorine；
(2) choice experiment condition：Detector voltage, excitation voltage, excitation current, minimum vacuum degree parameter are set；
(3) X- fluorescent spectrometry is utilized, the fluorescence intensity of chloride series standard specimen is determined, the total chlorine that sets up in chloride series standard specimen contains
Amount and the corresponding relation of fluorescence intensity, draw the calibration curve of chloride series standard specimen；
The measure of the 3rd step sample：
(1) X- fluorescent spectrometry is utilized, determines the fluorescence intensity of total chlorine in the doctor solution sample being placed in light-permeable closed container；
(2) using the calibration curve of chloride series standard specimen, the content of total chlorine in doctor solution sample is calculated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610881791.2A CN106483157B (en) | 2016-10-09 | 2016-10-09 | Method for measuring total chlorine in desulfurization solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610881791.2A CN106483157B (en) | 2016-10-09 | 2016-10-09 | Method for measuring total chlorine in desulfurization solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106483157A true CN106483157A (en) | 2017-03-08 |
| CN106483157B CN106483157B (en) | 2021-12-28 |
Family
ID=58269358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610881791.2A Active CN106483157B (en) | 2016-10-09 | 2016-10-09 | Method for measuring total chlorine in desulfurization solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106483157B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111103315A (en) * | 2019-12-06 | 2020-05-05 | 北京清析技术研究院 | XRF-based method for rapidly detecting concentration of chloride ions in concrete |
| CN114113174A (en) * | 2021-12-17 | 2022-03-01 | 西南石油大学 | Device and method for testing unblocking effect of sulfur dissolving agent of sulfur deposition rock sample based on X-ray |
| CN114486800A (en) * | 2020-10-27 | 2022-05-13 | 中国石油化工股份有限公司 | Method for measuring content of hydrogen sulfide in liquid sulfur and method for measuring initial content of hydrogen polysulfide in liquid sulfur |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1609596A (en) * | 2004-11-22 | 2005-04-27 | 太原理工大学 | Method for measuring tannin extract content in tannin extract doctor solution |
| CN1844892A (en) * | 2006-03-09 | 2006-10-11 | 太原理工大学 | Process for determining vanadium content in desulfurizing liquid |
| CN103588323A (en) * | 2013-11-15 | 2014-02-19 | 湖南华菱湘潭钢铁有限公司 | Method for recycling sintering desulfurization waste liquid |
| CN104155270A (en) * | 2014-07-18 | 2014-11-19 | 中国海洋大学 | Fluorescent detection method for phenylamine |
| CN104368231A (en) * | 2014-10-10 | 2015-02-25 | 江苏新世纪江南环保股份有限公司 | Method for controlling chlorine / fluorine content in flue gas desulfurization absorption liquid |
| CN104849273A (en) * | 2015-06-04 | 2015-08-19 | 山东钢铁股份有限公司 | Method for rapidly testing thiocyanate ions in coking desulfurization liquid |
-
2016
- 2016-10-09 CN CN201610881791.2A patent/CN106483157B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1609596A (en) * | 2004-11-22 | 2005-04-27 | 太原理工大学 | Method for measuring tannin extract content in tannin extract doctor solution |
| CN1844892A (en) * | 2006-03-09 | 2006-10-11 | 太原理工大学 | Process for determining vanadium content in desulfurizing liquid |
| CN103588323A (en) * | 2013-11-15 | 2014-02-19 | 湖南华菱湘潭钢铁有限公司 | Method for recycling sintering desulfurization waste liquid |
| CN104155270A (en) * | 2014-07-18 | 2014-11-19 | 中国海洋大学 | Fluorescent detection method for phenylamine |
| CN104368231A (en) * | 2014-10-10 | 2015-02-25 | 江苏新世纪江南环保股份有限公司 | Method for controlling chlorine / fluorine content in flue gas desulfurization absorption liquid |
| CN104849273A (en) * | 2015-06-04 | 2015-08-19 | 山东钢铁股份有限公司 | Method for rapidly testing thiocyanate ions in coking desulfurization liquid |
Non-Patent Citations (6)
| Title |
|---|
| 何德捷 等: ""X射线荧光光谱法测定催化剂中铁镍铜"", 《岩矿测试》 * |
| 屠湧涛 等: ""邻-甲联苯胺法测定血浆游离血红蛋白的基质效应及消除方法"", 《检验医学》 * |
| 张辉 等: ""脱硫系统中碱液及污水氯离子含量的测定研究"", 《兰州石化职业技术学院学报》 * |
| 王晓楠 等: ""水中氯化物检测及样品前处理技术研究进展"", 《理化检验-化学分册》 * |
| 轩慎友 等: ""X单波段荧光分析法测定胺液中的氯含量"", 《化工管理》 * |
| 郝新焕 等: ""高含硫污水氯化物测定方法的改进和优化"", 《石油化工腐蚀与防护》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111103315A (en) * | 2019-12-06 | 2020-05-05 | 北京清析技术研究院 | XRF-based method for rapidly detecting concentration of chloride ions in concrete |
| CN114486800A (en) * | 2020-10-27 | 2022-05-13 | 中国石油化工股份有限公司 | Method for measuring content of hydrogen sulfide in liquid sulfur and method for measuring initial content of hydrogen polysulfide in liquid sulfur |
| CN114486800B (en) * | 2020-10-27 | 2024-04-26 | 中国石油化工股份有限公司 | Method for measuring content of hydrogen sulfide in liquid sulfur and method for measuring initial content of hydrogen polysulfide in liquid sulfur |
| CN114113174A (en) * | 2021-12-17 | 2022-03-01 | 西南石油大学 | Device and method for testing unblocking effect of sulfur dissolving agent of sulfur deposition rock sample based on X-ray |
| CN114113174B (en) * | 2021-12-17 | 2023-11-03 | 西南石油大学 | Sulfur deposition rock sample sulfur dissolving agent blocking removal effect testing device and method based on X-rays |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106483157B (en) | 2021-12-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bloom et al. | The quantitation of aqueous aluminum | |
| JP5925211B2 (en) | Method and apparatus for system parameter determination to reduce crude equipment corrosion | |
| Mohammadi et al. | Applicability of cloud point extraction for the separation trace amount of lead ion in environmental and biological samples prior to determination by flame atomic absorption spectrometry | |
| CN106483157A (en) | The determination method of total chlorine in a kind of doctor solution | |
| US20140373649A1 (en) | Use of detection techniques for contaminant and corrosion control in industrial processes | |
| CN104406943B (en) | Pretreatment method for liquid sample in laser-induced breakdown spectrum detection technology | |
| CN103994994A (en) | Method for analyzing silicon in ferro-vanadium | |
| CN105973824A (en) | Method for detecting heavy metals in wastewater | |
| Yuan et al. | Preconcentration and determination of tin in water samples by using cloud point extraction and graphite furnace atomic absorption spectrometry | |
| CN105784615A (en) | Method for measuring migration volume of trivalent arsenic and pentavalent arsenic in domestic drinking water contact material | |
| CN109580564B (en) | Method for detecting mercury ions in water | |
| CN103234957A (en) | Method for determining concentration of cyanides in environment | |
| CN103852509B (en) | Potentiometric titration analysis method for cyanide | |
| CN113049665B (en) | Apparatus and method for measuring content of sulfur isotope | |
| Snell | Colorimetric analysis | |
| CN113030347A (en) | Pretreatment device and method for determining soluble salt components based on ion chromatography | |
| CN209014454U (en) | Flow Injection Analysis measures the device of volatile phenol in underground water | |
| CN111443056A (en) | Method for measuring mercury content in copper concentrate | |
| Suzuki | Flow analytical systems for the determination of components in seawater | |
| CN113984871B (en) | Method for determining shale soluble organic carbon isotope by using EA-IRMS | |
| Nilsen et al. | The determination of weakly and strongly bound copper, lead and cadmium in Oslofjord samples | |
| Ensafi et al. | Determination of trace amount of carbon disulfide in water by the spectrophotometric reaction-rate method | |
| RU2776411C1 (en) | Method for determining the content of sulfide and polysulfide compounds in sediments in oilfield and oil refining equipment | |
| CN108107015A (en) | A kind of method for measuring Water quality ammonia nitrogen | |
| Jonca et al. | Verification of measurement capabilities of flame atomic spectrometry for the determination of sodium, potassium, magnesium, and calcium in natural fresh water part I. Comparison of recommended methods |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |