Detection method for simultaneously measuring three kinds of isocyanates by using precolumn derivatization-gas chromatography-mass spectrography

A gas chromatography and pre-column derivatization technology, which is used in the field of product detection and analysis, can solve problems such as ineffective application detection, and achieve the effects of cheap equipment, high test accuracy and high purity.

Active Publication Date: 2015-05-06
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The object of the present invention is to provide a method for simultaneous determination of 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI) and diphenylmethane diisocyanate (2,6-TDI) in leather, artificial leather and textiles. The detection method of isocyanate

Method used

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  • Detection method for simultaneously measuring three kinds of isocyanates by using precolumn derivatization-gas chromatography-mass spectrography
  • Detection method for simultaneously measuring three kinds of isocyanates by using precolumn derivatization-gas chromatography-mass spectrography
  • Detection method for simultaneously measuring three kinds of isocyanates by using precolumn derivatization-gas chromatography-mass spectrography

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Selection and optimization of gas chromatography-mass spectrometry parameters

[0043] In order to obtain suitable gas chromatography-mass spectrometry parameters, selection and optimization of experimental conditions and instrument parameters: Japan Shimadzu GC-MS-QP2010 gas chromatography-mass spectrometer, equipped with an automatic sampler;

[0044] (1) Selection of chromatographic column

[0045] Considering that DB-5ms (30m×0.25mm×0.25μm) has the largest amount of use in each testing center, it is found through experiments that the chromatographic peak shape under this chromatographic column is symmetrical and correspondingly high, so this chromatographic column is preferred as the experimental chromatographic column, Other chromatographic columns with comparable performance can also be selected;

[0046] (2) Optimization of the inlet temperature

[0047] Select different inlet temperatures and observe the change of the chromatographic peak area of ​​each target...

Embodiment 2

[0058] Determination of 2,4-TDI, 2,6-TDI and MDI Content in Leather Samples

[0059] (1) Sample preparation

[0060] Take a leather sample, cut it into pieces with a side length of 2mm~4mm, and mix well;

[0061] (2) Extraction and reaction of samples

[0062] Accurately weigh 1.0g of the above-mentioned leather sample (accurate to 0.0001g) and place it in a 50mL glass conical flask, add 20mL of acetone to mix well, close the lid tightly, place it in an ultrasonic cleaner for extraction for 30min, filter out the solvent, and then add 20mL Acetone, repeat the extraction once, combine the extracts in a 100mL rotary evaporator, and slowly evaporate to dryness with a rotary evaporator in a 30°C water bath;

[0063] (3) Derivatization reaction

[0064] Accurately pipette 10mL of the residue in the acidic aqueous reaction rotary steamer, vortex for 3min, pipette 2mL of the reacted test solution into a 10mL test tube, add sodium hydroxide solution to neutralize the excess acid, mi...

Embodiment 3

[0090] Establishment of 2,4-TDA, 2,6-TDA or MDA linear relationship in the detection of leather, artificial leather and textiles

[0091] Using the method in Example 2, use the standard solution of 2,4-TDA, 2,6-TDA or MDA diluted with blank matrix solution for GC-MS analysis, the prepared concentrations are: 1 mg / L, 2 mg / L , 5mg / L, 10 mg / L, the determination results were analyzed by the workstation software, the determination linear range was 1~10mg / L, and the detection limit LOD was 1mg / L. Taking leather as an example, the standard curve diagram obtained is shown in Figure 6~8 , the abscissa in the figure indicates the concentration (mg / L), and the ordinate indicates the peak area of ​​the total ratio. For actual samples, the measured bottom line LOQ is less than 2 μg / mL. Under the experimental conditions determined by this method, the linear equations and correlation coefficients of other matrices are shown in Table 3 (where Y is the peak area, X is the concentration of th...

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Abstract

The invention provides a detection method for simultaneously measuring residual toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI) and diphenylmethane diisocyanate (MDI) in the product by using precolumn derivatization-gas chromatography-mass spectrography. The method comprises the following specific steps: performing ultrasonic extraction on a sample, performing rotary evaporation and concentration on the extracting solution, reacting in an acidic aqueous solution, neutralizing with an alkali liquor, extracting by using an organic solvent, performing organic phase derivatization, removing excessive derivatization reagents with a buffer solution, taking the organic phase as a to-be-measured solution after solution separation, measuring and confirming by using a gas chromatography-mass spectrometer, carrying out a blank experiment, quantifying by using an external standard method, measuring the target compound in the sample solution, and the like. According to the method, the measurement parameters and test steps of the gas chromatography-mass spectrography are reasonably selected, the content of 2,4-TDI, 2,6-TDI and MDI in leather, artificial leather and textiles can be simultaneously measured by adopting selective ion scanning detection and external standard method quantification, and the results are simultaneously obtained by virtue of one-step pretreatment. The method has the characteristics of high precision, high interference resistance and low detection limit.

Description

technical field [0001] The invention relates to the field of product detection and analysis, in particular to a detection method for simultaneous determination of three isocyanates (2,4-TDI, 2,6-TDI and MDI) remaining in products by pre-column derivatization-gas chromatography-mass spectrometry. Background technique [0002] Polyisocyanate monomers are important raw materials for the production of polyurethane coatings. At present, polyisocyanate monomers commonly used in industry include toluene 2,4-diisocyanate (2,4-TDI) (CAS: 584-84-9), toluene 2 ,6-diisocyanate (2,6-TDI) (CAS: 91-08-7), diphenylmethane diisocyanate (MDI) (CAS: 26447-40-5), hexamethylene diisocyanate (HDI) ( CAS: 822-06-0) and isophorone diisocyanate (IPDI) (CAS: 4098-71-9), among which TDI is the most used. The use of isocyanate monomers can improve the performance of polyurethane coatings, but it also endangers the health of people exposed to such compounds. Isocyanate compounds are one of the main che...

Claims

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Application Information

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IPC IPC(8): G01N30/88
Inventor 林炜桑军张晓镭王春华解书冬
Owner SICHUAN UNIV
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