Method for detection of metal elements in liquid crystal materials

Abstract

The invention discloses a method for detecting metal elements in liquid crystal materials, which includes the following steps: sample sampling: after splitting the thin film transistor liquid crystal display panel, use a scraper to scrape the liquid crystals on the side of the TFT substrate and the side of the CF substrate respectively, and collect the liquid crystals accurately with a balance Weigh the test sample; sample pretreatment: use solvent dilution method to dilute the test sample 8 to 12 times to obtain the analysis solution; send the analysis solution into an inductively coupled plasma mass spectrometer such as inductively coupled to detect metal elements in liquid crystal materials , quantified by external standard method. The metal element detection method of the liquid crystal material of the invention can quickly and accurately analyze the concentration of the metal element in the liquid crystal.

Description

technical field [0001] The invention relates to the field of detection of display liquid crystal materials, in particular to a method for detecting metal elements of liquid crystal materials. Background technique [0002] Liquid crystal screens are based on liquid crystal materials. Liquid crystals are between solid and liquid. They have the optical characteristics of solid crystals and the flow characteristics of liquids. When the light enters the liquid crystal material, it travels according to the arrangement of the liquid crystal molecules, resulting in a natural deflection phenomenon. At the same time, the electronic structure in the liquid crystal molecules has a strong electronic conjugate movement ability. When the liquid crystal molecules are subjected to an external electric field, they are easily polarized to generate induced dipolarity, which is also the source of the interaction force between liquid crystal molecules. Liquid crystal displays for general electro...

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Problems solved by technology

[0004] Currently, inductively coupled plasma mass spectrometry (ICPMS) is mainly used to detect heavy metal elements in liquid crystals. However, the existing sampling methods, such as solution washing, are quick to sample, but the sampling repeatability is poor. Duration (2 hours); Existing pretreatment methods such as microwave elimination method need to add about 10g of nitric acid during the digestion process. After the digestion is completed, the volume is fixed in a 100ml volumetric flask. The dilution factor of the sample is about 250 times. The concentration of metal elements in the liquid crystal is ppb level, after high-fold dilution, the metal elements in the dilution are likely to be lower than the detection limit of the equipment, the detection ability is greatly reduced and detection impurities are introduced; the advantage of quantitative methods such as standard addition method is that the influence of the matrix can be eliminated, and the disadvantage is that each A series of standard products need to be prepared for each sample, and the amount of samples that can be tested is about 2-5 per day, which cannot meet the large number of testing needs of the project.

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