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Method for detecting diphenylmethane diisocyanate in workplace

A diisocyanate and detection method technology, applied in the direction of measuring devices, instruments, scientific instruments, etc., can solve the problems of low thermal conductivity, limitation, etc., and achieve the effect of improving separation efficiency, improving accuracy and speeding up

Pending Publication Date: 2021-06-29
JIANGSU TAIJIE INSPECTION TECH
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  • Description
  • Claims
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Problems solved by technology

[0003] Diphenylmethane diisocyanate is the main raw material for the manufacture of polyurethane elastomers. Polyurethane products made of diphenylmethane diisocyanate have shown good chemical stability such as high tear strength, low temperature resistance, softness, and low thermal conductivity. It is widely used in the production of polyurethane synthetic leather, artificial leather coating, polyurethane soft foam, rigid foam, etc., especially for building materials. At present, the detection method of diphenylmethane diisocyanate in the workplace has gas chromatography Compared with liquid chromatography, gas chromatography is more acceptable for its good separation ability, high sensitivity, fast analysis speed, and convenient operation. However, the detection of MDI by existing gas chromatography is limited by factors such as measurement range and packed column. , so this patent integrates an analytical method that can accurately quantify diphenylmethane diisocyanate in the workplace

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  • Method for detecting diphenylmethane diisocyanate in workplace
  • Method for detecting diphenylmethane diisocyanate in workplace

Examples

Experimental program
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Embodiment 1

[0023] Embodiment one, with reference to figure 1 , a kind of detection method of diphenylmethane diisocyanate in workplace, detection method comprises the following steps:

[0024] (a) Preparation of standard curve solution: Accurately weigh 0.0500g of 4,4'-diaminodiphenylmethane standard substance in a 25mL volumetric flask, dissolve in toluene to obtain a standard stock solution, and then accurately pipette 2.5mL of 4,4' - Diaminodiphenylmethane standard stock solution in a 10mL volumetric flask, dilute to the 10mL mark with toluene, mix well, and prepare a 0.5μg / mL standard use solution, take five dry centrifuge tubes with stoppers, add 0.08 mL, 0.2mL, 0.4mL, 0.8mL, 2mL standard solution, and then diluted to 2mL with toluene in each of the five stoppered centrifuge tubes to prepare 4,4 '-Diaminodiphenylmethane standard series, then add 30 μL of heptafluorobutyric anhydride to each of the five stoppered centrifuge tubes, shake for 2 minutes, let stand for 5 minutes, add po...

Embodiment 2

[0034] Embodiment two, a kind of detection method of diphenylmethane diisocyanate in workplace, detection method comprises the following steps:

[0035](a) Preparation of standard curve solution: Accurately weigh 0.0500g of 4,4'-diaminodiphenylmethane standard substance in a 25mL volumetric flask, dissolve in toluene to obtain a standard stock solution, and then accurately pipette 2.5mL of 4,4' - Diaminodiphenylmethane standard stock solution in a 10mL volumetric flask, dilute to the 10mL mark with toluene, mix well, and prepare a 0.5μg / mL standard use solution, take five dry centrifuge tubes with stoppers, add 0.04 mL, 0.1mL, 0.2mL, 0.3mL, 1mL standard solution, and then diluted to 2mL with toluene in each of the five stoppered centrifuge tubes to prepare 4,4 '-Diaminodiphenylmethane standard series, then add 30 μL of heptafluorobutyric anhydride to each of the five stoppered centrifuge tubes, shake for 2 minutes, let stand for 5 minutes, add potassium dihydrogen phosphate bu...

Embodiment 3

[0039] Embodiment three, a kind of detection method of diphenylmethane diisocyanate in workplace, detection method comprises the following steps:

[0040] (a) Preparation of standard curve solution: Accurately weigh 0.0500g of 4,4'-diaminodiphenylmethane standard substance in a 25mL volumetric flask, dissolve in toluene to obtain a standard stock solution, and then accurately pipette 2.5mL of 4,4' - Diaminodiphenylmethane standard stock solution in a 10mL volumetric flask, dilute to the 10mL mark with toluene, mix well, and prepare a 0.5μg / mL standard use solution, take five dry centrifuge tubes with stoppers, add 0.16 mL, 0.4mL, 0.8mL, 1.6mL, 2mL standard solution, and then diluted to 2mL with toluene in each of the five stoppered centrifuge tubes to prepare 4,4 '-Diaminodiphenylmethane standard series, then add 35 μL of heptafluorobutyric anhydride to each of the five stoppered centrifuge tubes, shake for 2 minutes, let stand for 5 minutes, add potassium dihydrogen phosphate...

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Abstract

The invention discloses a method for detecting diphenylmethane diisocyanate in a workplace. The method comprises the following steps: preparing a standard curve solution, collecting a sample, preparing a to-be-detected solution and carrying out gas phase detection, respectively detecting the standard solution and the sample preparation solution by using a gas chromatograph, and determining the peak area of a toluene extract in the sample; and determining the nature by retention time, and substituting the peak area into a standard curve for quantification. According to the method, a common capillary column in a laboratory is adopted to replace a standard packed column so that the separation efficiency is improved, and meanwhile, the analysis speed is increased; and the flow of an instrument column adopted by the invention is 1.5 mL / min so that the diphenylmethane diisocyanate can be better separated.

Description

technical field [0001] The invention belongs to the technical field of monitoring harmful substances in workplaces, in particular to a method for detecting diphenylmethane diisocyanate in workplaces. Background technique [0002] Diphenylmethane diisocyanate is abbreviated as "MDI". At room temperature, it is a white to light yellow solid, and it becomes a colorless to slightly yellow liquid after melting. It has a pungent odor when heated, soluble in benzene, toluene, chlorobenzene, nitrobenzene, acetone, ether, ethyl acetate, dioxane, etc. Inhalation of diphenylmethane diisocyanate vapor can cause respiratory irritation, headache, Runny nose, sore throat, wheezing, chest tightness, difficulty breathing, and decreased lung function. High concentration exposure can cause bronchitis, bronchospasm and pulmonary edema, eye contact can cause conjunctival irritation and moderate corneal clouding, skin contact can cause skin irritation, allergies and dermatitis. Ingestion can ca...

Claims

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Application Information

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IPC IPC(8): G01N30/02G01N30/04G01N30/06G01N30/32G01N30/60
CPCG01N30/02G01N30/06G01N30/04G01N30/32G01N30/6078G01N2030/025G01N2030/324G01N2030/042
Inventor 林新艳卢德文曹秋文俞晓明
Owner JIANGSU TAIJIE INSPECTION TECH
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