Method for detecting purity of organic electroluminescent material

Abstract

The invention relates to a method for detecting the purity of an organic electroluminescent material, which comprises the following steps of: firstly, transferring a solvent by adopting a bottleneck liquid separator in pretreatment; secondly, scientifically verifying separation and elution of impurities, so that the detection result is more accurate; then, determining the number of impurities and the maximum absorption wavelength through the 3D spectrum technology, and therefore, it is guaranteed that any impurity with ultraviolet absorption does not fall off in the detection process; and finally, using a variable wavelength technology for replacing a single wavelength technology of an original method, so that each substance in the sample has relatively large response, and misjudgment caused by no absorption of some compounds under a certain single wavelength is avoided. Compared with GB / T37949-2019, the optimized detection method for the compound shown in the formula (1) is simpler and more convenient to operate, and the working efficiency is improved; solvent volatilization is reduced, and pollution to the environment and damage to experimenters are reduced; the risk of cross contamination of the solvent is reduced; the use of consumables such as pipette heads is reduced; and zero waste of the organic solvent can be realized, and meanwhile, the result is more accurate.

Description

technical field [0001] The invention belongs to the technical field of organic compound detection, and in particular relates to a method for detecting the purity of organic electroluminescent materials. Background technique [0002] Organic Light-Emitting Diode (OLED, Organic Light-Emitting Diode), which was discovered in the laboratory by Chinese-American professor Ching W.Tang in 1979, has self-illumination, low energy consumption, and large viewing angle compared to traditional display technologies. and other excellent performances, but at the same time, there are also disadvantages such as short life, poor color purity, and low yield, which limit the application of OLED display technology. [0003] The purity of organic electroluminescent materials has a considerable impact on the life of the device. The first thing to judge whether a material can be used in an OLED device is to look at the purity of the material. Organic electroluminescent materials are repeatedly puri...

AI Technical Summary

Problems solved by technology

Organic electroluminescent materials are repeatedly purified by chemical and physical methods before use. At this time, the purity of the materials generally reaches more than 99%. Due to the detection limit of the instrument, the deviation of the quantitative method itself, and the difficulty of finding material standards, it is difficult to Analysis of Material Purity Using Routine Quantitative Methods

OLED materials obtained by chemical synthesis may still have residues such as moisture, ash, solvents, inorganic elements, inorganic acids, etc. that affect the purity of the material after purification methods such as recrystallization, column passing, and sublimation to remove impurities. These residues can be used separately Karl Fischer, ignition residue, TGA, ICPMS, ion chromatography and other means to monitor, in addition, the remaining organic impurities are generally by-products with similar physical and chemical properties to the main substance or degradation products of the main substance. Such impurities and material purity are detected by high performance liquid chromatography in GB / T 37949-2019, but for this standard method, there are some shortcomings that affect the accuracy of the results

[0004]First of all, it is the pre-processing in this standard method. For the detection work, the biggest factor causing the deviation of the test results is the sample pre-processing. If you want to obtain accurate and reliable data, it is scientific and reasonable. The pretreatment operation is the most important. In GB / T 37949-2019, the pretreatment method of the sample is to first measure a certain amount of solvent in the conical flask, and then use a pipette or pipette gun to measure a small amount as a blank In contrast, the remaining solvent is used to prepare the test sample, so the pretreatment operation will bring the following problems: 1. The solvent is repeatedly measured, and the operation is complicated, which is not conducive to the improvement of work efficiency; 2. The solvent used in organic electroluminescent materials is generally It is highly volatile, and according to the pretreatment method of the standard method, even if a sealed triangular flask is used, it will also volatilize during the measuring and pipetting process, pollute the environment, and damage the health of the experimenter; 3. If the pipette and pipette tip are not clean Or there is dissolution, the solvent has the risk of being cross-contaminated, and false sample blank data will be obtained; 4. For the "remaining solvent used to prepare test samples" in the standard method, whether the sample is weighed and poured in For the remaining solvent, find another container to weigh the sample and then pour the remaining solvent into it. It is not easy to operate, and it will increase the risk of solvent volatilization and cross-contamination

However, in actual operation, it is almost impossible to meet the above conditions at the same time. At this time, if the properties of the main substance and impurities of the sample are not studied in depth, and the detection parameters are not set scientifically, the obtained detection data may be worthless. of

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