CN114384175B - Method for detecting TDI content in soil by high performance liquid chromatography - Google Patents
Method for detecting TDI content in soil by high performance liquid chromatography Download PDFInfo
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- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 claims description 79
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/86—Signal analysis
- G01N30/8624—Detection of slopes or peaks; baseline correction
- G01N30/8631—Peaks
- G01N30/8634—Peak quality criteria
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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Abstract
The invention provides a method for detecting TDI content in soil by high performance liquid chromatography, belonging to the technical field of soil detection. The method comprises the following steps: (1) soil pretreatment; (2) high performance liquid chromatography detection; (3) data analysis: taking the mass concentration X of TDI in a standard working solution as an abscissa, the peak area Y of TDI as an ordinate, drawing a standard working curve, quantifying a sample by an external standard method by using the standard working curve, and qualitatively determining the sample by using the retention time of chromatographic peaks appearing in a sample solution; the method for detecting the TDI content in the soil by the high performance liquid chromatography is simple and convenient to operate, high in accuracy, strong in specificity and good in reproducibility, and the method can be used for various soils with large property differences, and has good accuracy and precision in detection results in various batches of soils by strictly controlling the liquid chromatography conditions.
Description
Technical Field
The invention belongs to the technical field of soil detection, and particularly relates to a method for detecting TDI content in soil by high performance liquid chromatography.
Background
Toluene-2, 4-diisocyanate (TDI) is commonly used as a raw material for polyurethane flexible foam, paint, rubber, fiber and adhesive, and has wide application. TDI is inflammable when exposed to open fire and high heat, can react with oxidant, and is violent in reaction with amine, alcohol, alkali and warm water, can cause combustion or explosion, can decompose and generate toxic gas when heated or combusted, has vapor heavier than air, can spread to quite far places at lower places, can catch fire when meeting fire source, and if meeting high heat, the internal pressure of a container is increased, and has the danger of cracking and explosion.
TDI is a volatile toxic substance that can react with human proteins to denature the proteins, thus causing the greatest hazard to the human body. The vapors of TDI have strong tear action and, after inhalation, stimulate the respiratory system, causing dry cough, sore throat, headache, bronchitis and asthma, which seriously lead to death.
Along with the development of social science and technology, the speed of grabbing resources is rapidly increased, and the problem of environmental pollution, namely, pollution which is difficult to reverse due to garbage accumulation caused by industrial emission and urban dense population, is caused. Therefore, environmental protection has become the first problem in the new century. The method has the advantages that various data monitoring needs of the environment are brought, the pollution can be treated in a targeted manner only by monitoring various environmental data in real time, and the pollution source is controlled by adopting an effective means, so that when the soil contains TDI, serious environmental threat can be generated, irreversible damage can be caused to human bodies, the TDI polluted soil is treated, the TDI polluted soil is detected, and no related method for pretreatment and detection of the TDI in the soil exists at present, so that an accurate and efficient detection method is needed to meet the use requirement.
Disclosure of Invention
Aiming at the problems, the invention provides a method for detecting the TDI content in soil by using high performance liquid chromatography, which is simple and convenient to operate and high in accuracy, and the method can be used for various soils with large property differences, and has good accuracy and precision in detection results in various batches of soils.
The technical scheme of the invention is as follows: the method for detecting the TDI content in the soil by using the high performance liquid chromatography comprises the following steps:
(1) Soil pretreatment:
weighing 5.00g of soil sample to be tested, adding 5mL of acetonitrile into the soil sample, uniformly mixing, carrying out ultrasonic extraction for 1min, centrifuging for 10min at a rotating speed of 6000r/min, taking 1mL of supernatant, passing through a 0.22um filter membrane to obtain a sample solution, and loading the sample solution to be tested;
(2) High performance liquid chromatography detection:
a. preparation of standard solution: accurately weighing TDI standard substances respectively, dissolving the TDI standard substances by using acetonitrile to prepare a standard stock solution of 0.2mg/mL, and diluting the TDI standard substances into a standard working solution by using acetonitrile according to the estimated concentration of TDI in soil when the TDI standard substance is used;
b. detection of standard working solution and sample solution: respectively sucking standard working solution and sample solution by an automatic sampler, injecting into high performance liquid chromatography, separating TDI in the sample by a liquid chromatography column, and detecting by a detector;
(3) Data analysis: and (3) drawing a standard working curve by taking the mass concentration X of TDI in the standard working solution as an abscissa and the peak area Y of TDI as an ordinate, quantifying the sample by an external standard method by using the standard working curve, and qualitatively determining the sample by using the retention time of chromatographic peaks appearing in the sample solution.
Further, the liquid chromatography conditions in the step (2) are as follows: chromatographic column: SB-C184.6X105 mm 5um; mobile phase: a is ultrapure water, B is acetonitrile; b=40:60; column temperature: 30 ℃; a detector: the ultraviolet detector has the detection wavelength of 230nm and the reference wavelength of 360nm, and the established detection method has high accuracy, strong specificity and good reproducibility by strictly controlling the liquid chromatography condition, so that the TDI content in the soil can be effectively detected.
Further, in the step (1), the prepared sample solution is subjected to reduced pressure distillation treatment, and the specific treatment process is as follows:
s1, adding the sample solution prepared in the step (1) into a flask, and blowing nitrogen into the flask through a branch pipe for 10-15min until air and water vapor in the flask are removed;
s2, connecting the flask with a fractionation device and a decompression device, vacuumizing to P <1.5KPa, and heating the flask at 70-80 ℃ until the sample solution boils;
s3, setting the reflux ratio to be 1:3 under standard atmospheric pressure, and collecting fractional distillate until the temperature of the top of the fractionating column is 280-290 ℃;
s4: setting the decompression fractionating system to be total reflux, stopping heating, cooling the sample solution in the flask to 40-60 ℃ under the decompression state, and continuously introducing nitrogen into the flask for purging until the normal pressure is reached;
s5, taking down the flask, respectively weighing the separated liquid and residual liquid, and carrying out reduced pressure distillation to re-precipitate the hydrolyzed TDI in the sample solution, so that the loss of TDI can be avoided, the purity in the sample solution is increased, and the reduction of the sensitivity and accuracy of detection due to low concentration of TDI in the sample solution is avoided.
Further, the acetonitrile used in the steps (1) and (2) is subjected to oxidation purification treatment, and the specific treatment process is as follows: first, the molar ratio is taken as 1:1 acetonitrile to be treated and K 2 Cr 2 O 7 The solution was prepared and the acetonitrile was equally divided into 3-5 parts, and then the above K was added in an equal amount to each part of acetonitrile 2 Cr 2 O 7 The solution forms a mixed solution, ultrasonic stirring and heating are carried out, when the temperature reaches 65-70 ℃, the cooling water of a return pipe is opened to enable the solution to return for 10-15min, finally, the components are sampled and analyzed to obtain the purified acetonitrile product, and the acetonitrile product is treated by a strong oxidant K 2 Cr 2 O 7 The solution is mixed with acetonitrile, so that the byproduct acrylonitrile produced in acetonitrile production can be oxidized and removed, the purity of acetonitrile is increased, the reduction of the solubility of TDI due to poor purity of acetonitrile is avoided, the accuracy of the measured TDI content is reduced, and meanwhile, the oxidation position of acetonitrile is also reducedWhen the method is used, the waste water is uniformly divided into multiple components to be treated, so that the oxidation treatment time can be shortened, and the working efficiency can be improved.
Further, the acetonitrile to be treated has an organic component content of 98.6 to 99.3wt%, and the K 2 Cr 2 O 7 The mass concentration of the solution is 4-5%.
Further, in the step a, the preservation method of the standard substance TDI is as follows: under the protection of nitrogen gas, cross heap with standard product TDI and drier package is piled up and is placed in holding the container to place the shade and dry department and store in the light-proof, wherein hold container inner wall subsides and be equipped with the hydrophobic material layer, outer wall subsides are equipped with the light-proof material layer, through placing standard product TDI in the inner wall subsides be equipped with the hydrophobic material layer and outer wall subsides are equipped with the light-proof material layer hold the container in, can avoid light to avoid the light color to become dark or meet the water decomposition, guarantee the quality of TDI, thereby influence measurement accuracy.
Further, the drier is anhydrous sodium sulfate, the hydrophobic material is polycarbonate, the light-resistant material is polyethylene, and the TDI is prevented from being deepened or decomposed when meeting light, so that the measurement accuracy is influenced.
Further, in the step (1), before acetonitrile is added into a soil sample to be detected, impurities in the soil are removed, then, the soil is ground for multiple times by utilizing a grinding device, finally, the ground soil is added into a centrifugal machine for centrifugal rotation, and the soil is dried by matching with heating gas, so that the impurity removal, grinding and drying are carried out on the soil, and the accuracy of soil detection is improved.
Further, the filter membrane in the step (1) is a nylon filter membrane, and the detector in the step b is an ultraviolet detector.
Compared with the prior art, the invention has the beneficial effects that:
(1) The method for detecting the TDI content in the soil by the high performance liquid chromatography is simple and convenient to operate, high in accuracy, and high in specificity and good in reproducibility by strictly controlling the liquid chromatography conditions, can be used for various soils with large property differences, and has good accuracy and precision in detection results in various batches of soils.
(2) The method can re-separate the hydrolyzed TDI in the sample solution by distilling the sample solution under reduced pressure, thereby avoiding TDI loss, increasing the purity of the sample solution and avoiding the reduction of the sensitivity and accuracy of detection due to low concentration of TDI in the sample solution.
(3) According to the invention, acetonitrile is subjected to oxidation and purification treatment, so that acrylonitrile which is a byproduct of acetonitrile production can be oxidized and removed, the purity of acetonitrile is increased, the reduction of TDI solubility caused by poor purity of acetonitrile is avoided, the accuracy of the measured TDI content is reduced, and meanwhile, the acetonitrile is uniformly divided into multiple components for treatment during oxidation treatment, so that the oxidation treatment time is shortened, and the working efficiency is improved.
(4) According to the invention, the standard TDI is placed in the container with the hydrophobic material layer adhered on the inner wall and the light-shading material layer adhered on the outer wall, so that light shading and water proofing can be realized, the quality of TDI is ensured, and the light color deepening or water decomposition of the TDI is avoided, thereby influencing the measurement accuracy.
Drawings
FIG. 1 is a TDI chromatogram of the present invention;
fig. 2 is a TDI standard graph of the present invention.
Detailed Description
Example 1
The method for detecting the TDI content in the soil by using the high performance liquid chromatography comprises the following steps:
(1) Soil pretreatment:
weighing 5.00g of soil sample to be tested, adding 5mL of acetonitrile into the soil sample, uniformly mixing, carrying out ultrasonic extraction for 1min, centrifuging for 10min at a rotating speed of 6000r/min, taking 1mL of supernatant, passing through a nylon filter membrane of 0.22um to obtain a sample solution, and loading the sample solution to be tested;
(2) High performance liquid chromatography detection:
a. preparation of standard solution: accurately weighing TDI standard substances respectively, dissolving the TDI standard substances by using acetonitrile to prepare a standard stock solution of 0.2mg/mL, and diluting the TDI standard substances into a standard working solution by using acetonitrile according to the estimated concentration of TDI in soil when the TDI standard substance is used;
b. detection of standard working solution and sample solution: the automatic sampler is used for respectively sucking standard working solution and sample solution, injecting the standard working solution and the sample solution into a high performance liquid chromatograph, separating TDI in the sample by a liquid chromatographic column, detecting by an ultraviolet detector, and obtaining a TDI chromatogram, wherein the horizontal coordinate is time, the vertical coordinate is response signal, the target substance TDI shows a peak at 7.821 minutes, the front irregular peak is a solvent peak and an interference peak, the retention time of the chromatogram is 7.821 minutes, and the peak area is 40.13 mAU.
Wherein, the liquid chromatography conditions are as follows: chromatographic column: SB-C18.6X105 mm 5um; mobile phase: a is ultrapure water, B is acetonitrile; b=40:60; column temperature: 30 ℃; a detector: the ultraviolet detector has the detection wavelength of 230nm and the reference wavelength of 360nm, and the established detection method has high accuracy, strong specificity and good reproducibility by strictly controlling the liquid chromatography condition, so that the TDI content in the soil can be effectively detected;
(3) Data analysis: the standard working curve is drawn by taking the mass concentration X of TDI in the standard working solution as an abscissa and the peak area Y of the TDI as an ordinate, and as shown in fig. 2, the relation between the peak area Y of the TDI and the abscissa X is as follows: y=mx+b, m and b are constants, m is 19.39527, b is-1.76900, when a sample with unknown concentration is subjected to liquid chromatography, the liquid chromatography gives a peak area, and then the concentration of TDI in the sample can be calculated according to the formula and the peak area; the external standard method is used for quantifying the sample by using a standard working curve, and the sample is characterized by using the retention time of chromatographic peaks appearing in the sample solution.
Example 2
This embodiment is substantially the same as embodiment 1 except that:
in the step (1), the prepared sample solution is subjected to reduced pressure distillation treatment, and the specific treatment process comprises the following steps:
s1, adding the sample solution prepared in the step (1) into a flask, and blowing nitrogen into the flask through a branch pipe for 13min until air and water vapor in the flask are removed;
s2, connecting the flask with a fractionation device and a decompression device, vacuumizing to P <1.5KPa, and heating the flask at 75 ℃ until the sample solution boils;
s3, setting the reflux ratio to be 1:3 under standard atmospheric pressure, and collecting fractional distillates until the top temperature of the fractional column is 285 ℃;
s4: setting the decompression fractionating system as total reflux, stopping heating, cooling the sample solution in the flask to 50 ℃ under the decompression state, and continuously introducing nitrogen into the flask for purging until the normal pressure is reached;
s5, taking down the flask, respectively weighing the separated liquid and residual liquid, and carrying out reduced pressure distillation to re-precipitate the hydrolyzed TDI in the sample solution, so that the loss of TDI can be avoided, the purity in the sample solution is increased, and the reduction of the sensitivity and accuracy of detection due to low concentration of TDI in the sample solution is avoided.
Example 3
This embodiment is substantially the same as embodiment 2 except that:
the acetonitrile used in the steps (1) and (2) is subjected to oxidation and purification treatment, and the specific treatment process is as follows: first, the molar ratio is taken as 1:1 acetonitrile to be treated and K 2 Cr 2 O 7 The solution was prepared and acetonitrile was equally divided into 4 parts, and then the above K was added in an equal amount to each part of acetonitrile 2 Cr 2 O 7 The solution forms a mixed solution, ultrasonic stirring and heating are carried out, when the temperature reaches 65 ℃, the cooling water of a return pipe is opened to enable the solution to return for 13min, finally, the components are sampled and analyzed to obtain the purified acetonitrile product, and the acetonitrile product is treated by a strong oxidant K 2 Cr 2 O 7 The solution is mixed with acetonitrile, so that acrylonitrile which is a byproduct of acetonitrile production can be oxidized and removed, the purity of acetonitrile is increased, the reduction of the solubility of TDI (toluene diisocyanate) due to poor purity of acetonitrile is avoided, the accuracy of the measured TDI content is reduced, and meanwhile, the acetonitrile is uniformly divided into multiple components for treatment during oxidation treatment, so that the oxidation treatment time is shortened, and the working efficiency is improved;
the organic component content of the acetonitrile to be treated is 99.3 weight percent, and the K 2 Cr 2 O 7 The mass concentration of the solution was 4%.
Example 4
This embodiment is substantially the same as embodiment 3 except that:
in the step a, the preservation method of the standard substance TDI comprises the following steps: under the protection of nitrogen, the standard substance TDI and the drying agent bag are alternately stacked in a container and are placed in a shady and dry place for light-proof storage, wherein a hydrophobic material layer is stuck on the inner wall of the container, a light-proof material layer is stuck on the outer wall of the container, the quality of the TDI is ensured by putting the standard substance TDI on the inner wall of the container and sticking the hydrophobic and waterproof materials, the light color of the TDI is prevented from deepening or decomposing when the TDI is encountered with water, and therefore the measurement accuracy is influenced, and the light-proof material layer is stuck on the outer wall of the container;
the drier is anhydrous sodium sulfate, the hydrophobic material is polycarbonate, the light-resistant material is polyethylene, and the TDI is prevented from being deepened or decomposed when meeting light color or water through water-proof and light-resistant preservation, so that the measurement accuracy is affected.
Example 5
This embodiment is substantially the same as embodiment 4 except that:
in the step (1), before acetonitrile is added into a soil sample to be detected, impurities in the soil are removed, then, the soil is ground for multiple times by utilizing a grinding device, finally, the ground soil is added into a centrifugal machine for centrifugal rotation, and the soil is dried by matching with heating gas, so that the impurity removal and grinding of the soil are realized, and the accuracy of soil detection is improved.
Claims (1)
1. The method for detecting the toluene-2, 4-diisocyanate content in soil by using high performance liquid chromatography is characterized by comprising the following steps of:
(1) Soil pretreatment:
weighing 5.00g of soil sample to be tested, adding 5mL of acetonitrile into the soil sample, uniformly mixing, carrying out ultrasonic extraction for 1min, centrifuging for 10min at a rotating speed of 6000r/min, taking 1mL of supernatant, passing through a 0.22 mu m filter membrane to obtain a sample solution, and loading the sample solution to be tested;
(2) High performance liquid chromatography detection:
a. preparation of standard solution: respectively and accurately weighing standard toluene-2, 4-diisocyanate, dissolving the standard toluene-2, 4-diisocyanate by using acetonitrile to prepare a standard stock solution of 0.2mg/mL, and diluting the standard stock solution into a standard working solution by using acetonitrile according to the estimated concentration of toluene-2, 4-diisocyanate in soil when the standard stock solution is used;
b. detection of standard working solution and sample solution: respectively sucking standard working solution and sample solution by an automatic sampler, injecting into high performance liquid chromatography, separating toluene-2, 4-diisocyanate in the sample by a liquid chromatography column, and detecting by a detector;
(3) Data analysis: taking the mass concentration X of toluene-2, 4-diisocyanate in a standard working solution as an abscissa and the peak area Y of toluene-2, 4-diisocyanate as an ordinate, drawing a standard working curve, quantifying a sample by an external standard method by using the standard working curve, and qualitatively detecting the sample by using the retention time of chromatographic peaks appearing in a sample solution;
in the step (1), the prepared sample solution is subjected to reduced pressure distillation treatment, and the specific treatment process comprises the following steps:
s1, adding the sample solution prepared in the step (1) into a flask, and blowing nitrogen into the flask through a branch pipe for 10-15min until air and water vapor in the flask are removed;
s2, connecting the flask with a fractionation device and a decompression device, vacuumizing to P <1.5KPa, and heating the flask at 70-80 ℃ until the sample solution boils;
s3, setting the reflux ratio to be 1:3 under standard atmospheric pressure, and collecting fractional distillate until the temperature of the top of the fractionating column is 280-290 ℃;
s4: setting the decompression fractionating system to be total reflux, stopping heating, cooling the sample solution in the flask to 40-60 ℃ under the decompression state, and continuously introducing nitrogen into the flask for purging until the normal pressure is reached;
s5, taking down the flask, and weighing the separated liquid and residual liquid respectively;
the acetonitrile used in the steps (1) and (2) is subjected to oxidation and purification treatment, and the specific treatment process is as follows: first, the molar ratio is taken as 1:1 acetonitrile to be treated and K 2 Cr 2 O 7 The solution was prepared and the acetonitrile was equally divided into 3-5 parts, and then the above K was added in an equal amount to each part of acetonitrile 2 Cr 2 O 7 Forming a mixed solution by the solution, stirring and heating by ultrasonic waves, opening cooling water of a return pipe when the temperature reaches 65-70 ℃ to enable the solution to return for 10-15min, and finally, sampling and analyzing components to obtain a purified acetonitrile product;
the organic component content of the acetonitrile to be treated is 98.6-99.3wt%, and the K is 2 Cr 2 O 7 The mass concentration of the solution is 4-5%;
in the step a, the preservation method of the standard toluene-2, 4-diisocyanate comprises the following steps: under the protection of nitrogen, the standard toluene-2, 4-diisocyanate and a drying agent bag are alternately stacked in a container and stored in a shade and dry place, wherein a hydrophobic material layer is stuck on the inner wall of the container, and a light-shielding material layer is stuck on the outer wall of the container;
the drying agent is anhydrous sodium sulfate, the hydrophobic material is polycarbonate, and the light-shielding material is polyethylene;
in the step (1), before acetonitrile is added into a soil sample to be detected, impurities in the soil are removed, then the soil is ground for a plurality of times by using a grinding device, and finally the ground soil is added into a centrifuge for centrifugal rotation and is dried by matching with heating gas;
the liquid chromatography conditions in the step (2) are as follows: chromatographic column: SB-C18.6X105 mm 5 μm; mobile phase: a is ultrapure water, B is acetonitrile; b=40:60; column temperature: 30 ℃; a detector: an ultraviolet detector for detecting 230nm of wavelength and 360nm of reference wavelength;
the filter membrane in the step (1) is a nylon filter membrane, and the detector in the step b is an ultraviolet detector.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215493A (en) * | 2013-06-05 | 2014-12-17 | 中国石油天然气股份有限公司 | Vacuum distillation apparatus and test method for determining content of polycyclic aromatic hydrocarbon in light lubricating oil |
| CN104529821A (en) * | 2014-12-31 | 2015-04-22 | 南通醋酸化工股份有限公司 | Method for removing acrylonitrile in acetonitrile product |
-
2021
- 2021-12-24 CN CN202111596567.6A patent/CN114384175B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215493A (en) * | 2013-06-05 | 2014-12-17 | 中国石油天然气股份有限公司 | Vacuum distillation apparatus and test method for determining content of polycyclic aromatic hydrocarbon in light lubricating oil |
| CN104529821A (en) * | 2014-12-31 | 2015-04-22 | 南通醋酸化工股份有限公司 | Method for removing acrylonitrile in acetonitrile product |
Non-Patent Citations (9)
| Title |
|---|
| Determination of free toluene diisocyanate in polyurethane prepolymers by high-performance liquid chromatography;P. McFadyen 等;Journal of Chromatography A;第123卷;第468-473页 * |
| Improved method for determination of traces of isocyanates in working atmospheres by high performance liquid chromatography;C. Sangö 等;Journal of Liquid Chromatography;第2卷(第6期);第763-774页 * |
| 上海市劳动卫生职业病防治院 等.高分子化合物的毒性和防护.人民卫生出版社,1974,第188-189页. * |
| 东亚地区酸沉降监测网中国分中心.东亚地区酸沉降监测技术指南.中国环境科学出版社,2002,第156页. * |
| 兰婉玲.药用复合硬片中甲苯二异氰酸酯单体残留检测.包装工程.2018,第39卷(第1期),第53-57页. * |
| 曲径 等.食品卫生与安全控制学.化学工业出版社,2006,第227页. * |
| 武海燕 等.装饰装修材料有害物质检测.北京理工大学出版社,2012,第80-81页. * |
| 胡小键 等.LC-MS/MS法直接测定水中甲苯二异氰酸酯.环境卫生学杂志.2016,第6卷(第3期),第234-236+241页. * |
| 高效液相色谱法测定工作场所空气中甲苯二异氰酸酯;张先蕊 等;中国职业医学;第42卷(第6期);第661-663页 * |
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