Detection method for ethlenethiourea in plastic products

A detection method and technology of ethyl thiourea, applied in the detection field of ethylene thiourea, can solve the problems of low accuracy of quantitative analysis and long detection time, and achieve the effect of good linear relationship and high accuracy

Active Publication Date: 2015-04-08
广电计量检测集团股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, the detection of ethylene thiourea mainly adopts gas chromatography analysis method, which has the problems of long detection time, qualitative and quantitative analysis, especially quantitative analysis and detection accuracy is not high, especially for plastic products, due to contact Therefore, a fast and accurate detection method for analyzing the content of ethylene thiourea in plastic products is needed to achieve the purpose of controlling the use of ethylene thiourea

Method used

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  • Detection method for ethlenethiourea in plastic products
  • Detection method for ethlenethiourea in plastic products
  • Detection method for ethlenethiourea in plastic products

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] 1. Pretreatment of samples

[0060] S1: Take a sample from the clean part of the plastic sample, cut it into pieces below 2mm×2mm×2mm, weigh 1g±0.1g (accurate to 0.1mg) of the sample into a 60ml glass reaction bottle, add 10ml of methanol, extract for 1h, repeat the above Operate once, combine the extracts twice, mix well, concentrate with a rotary evaporator to a small amount, then slowly blow nitrogen to dryness, then use methanol to make the volume to 1ml, and finally filter the sample through a 0.45um microporous membrane, Obtain the sample to be tested.

[0061] S2: Accurately weigh 0.01015g of ethylene thiourea standard product with a 100,000 graded analytical balance, add it to a 10ml volumetric flask, dissolve it in methanol to make a standard stock solution of 1000mg / L, and then dilute it step by step to 0.01 mg / L, 0.02mg / L, 0.05 mg / L, 0.1 mg / L, 0.2 mg / L, 0.5 mg / L, 1 mg / L standard working solutions.

[0062] 2. The sample to be tested and the standard working...

Embodiment 2

[0090] Example 2: Detection limit determination

[0091] Figure 4 It is the diode array diagram and the mass spectrogram of the 0.01mg / L ethylenethiourea standard substance that is the concentration of embodiment 2 of the present invention;

[0092] The standard samples with different concentrations were detected and analyzed by Figure 4 It can be concluded that the detection limit (3 times the signal-to-noise ratio) of ethylenethiourea can reach 0.01mg / L. The limit for each compound in the REACH regulation is 1000 mg / kg. It can be seen that this method can fully meet the restriction requirements of the REACH regulation for ethylene thiourea.

Embodiment 3

[0093] Example 3: Precision experiment

[0094] According to the detection method provided by the present invention, the standard sample of ethylene thiourea with an intermediate concentration point of 0.1 mg / L is taken and measured continuously for 7 times, and the relative standard deviation is less than 4%, and the precision is good. The results are shown in Table 3.

[0095] Table 3 Precision test of ethylene thiourea

[0096] test count Ethylenethiourea 1 0.096 2 0.094 3 0.090 4 0.088 5 0.093 6 0.092 7 0.099 average value 0.093 Relative deviation 0.0037 relative standard deviation / % 3.94

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Abstract

The invention discloses a detection method for ethlenethiourea in plastic products. The detection method comprises pre-treating a sample, detecting by using an ultra-high performance liquid chromatography, diode array and mass spectrometry combined instrument, determining the nature through a diode array spectrogram and a mass spectrogram, and determining the quantity by employing an external standard method according to the absorbance peak area at the maximum absorption wavelength of the diode array spectrogram or the SIR ion response value peak area of the mass spectrogram. An extremely good chromatographic peak of a to-be detected sample can be obtained within 3 min according to the above method, extremely good separation effect can be obtained, the linearity in the concentration scope of 0.01-10 mg / L is good, the linearity dependent coefficients of the two detectors are both larger than 0.9995, the detection limit reaches 0.01 mg / L, the RSD (relative standard deviation) obtained through a repeatability experiment is less than 4%, and the added-standard recovery rate is 90%-110%. The method is simple, rapid, accurate and reliable, and satisfied detection requirements of REACH regulation on ethlenethiourea.

Description

technical field [0001] The invention relates to the technical field of detection of ethylene thiourea, in particular to a detection method of ethylene thiourea in plastic products. Background technique [0002] Ethylenethiourea, chemical formula C 3 h 6 N 2 S, an imidazoline vulcanization accelerator, the pure product is white needle crystal, insoluble in ethyl acetate, gasoline, carbon tetrachloride, toluene, slightly soluble in acetone, soluble in water, methanol and ethanol, with weak Ammonia smell. Ethylene thiourea has been widely used in the curing of neoprene and other rubbers, and is also used in small quantities in the production of pesticides. [0003] Because the products cured by ethylene thiourea have high tensile strength, small permanent compression deformation and short time consumption, they have been widely used in neoprene rubber, chlorosulfonated polyethylene rubber, chlorohydrin rubber, polyacrylate Rubber vulcanization (mainly neoprene products suc...

Claims

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Application Information

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IPC IPC(8): G01N30/02G01N30/06
Inventor 王华李支薇任祥祥王海鸣
Owner 广电计量检测集团股份有限公司
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