Method for effectively analyzing microplastics in grease-containing food sample

Abstract

The invention belongs to the technical field of environment detection, and particularly relates to a method for effectively analyzing microplastics in a grease-containing food sample, which comprises the following steps: step 1, taking N g (wet weight) of collected food samples (rice, meat, flour / wheaten food and the like) on aluminum-foil paper, freeze-drying for 12 hours, weighing the dry weight, putting the freeze-dried food samples into a beaker, and putting the beaker into a container; adding possible target substances (500 [mu] m PE, PET, PP and PS), and uniformly mixing; step 2, adding 50mL of digestion solution (HNO3: H2O2 = 4: 1V: V) into the sample, manually oscillating and shaking up for 15s, so that the digestion solution and the food sample are fully contacted and reacted, various incompletely digested oils and fats can be efficiently removed under the condition that the influence on the microplastics and the filter membrane is minimized, the types, abundance and corresponding characteristic forms of the microplastics in the food sample containing the oils and fats can be accurately analyzed, and the accuracy of the microplastics in the food sample containing the oils and fats can be improved. A powerful guarantee is provided for researching the micro-plastic in the food.

Description

technical field [0001] The invention relates to the technical field of environmental detection, in particular to a method for effectively analyzing microplastics in food samples containing oil. Background technique [0002] Microplastics refer to plastic particles with a particle size of less than 5mm, including primary microplastics and secondary microplastics. Primary microplastics refer to tiny plastic particles produced by factories and discharged through rivers and sewage treatment plants, such as microplastics in toothpaste and skin care products; secondary microplastics refer to large-particle plastics that have been exposed to the environment for a long time Plastic particles formed by physical, chemical and biological decomposition. In recent years, global plastic production has increased year by year. Plastic products can be seen everywhere in people's lives. The recycling measures for plastic waste are not perfect, which has led to the increasingly serious proble...

AI Technical Summary

Problems solved by technology

However, the edible oils and fats contained in the food samples that people eat daily are not only large in amount but also in various types. After using the current fast and efficient digestion method, there will still be oils and fats. Microplastics and grease, which not only increase filtration time but also reduce the accuracy of results

In addition, oil can interfere with vision when viewed under a microscope, adding to the difficulty of characterization, especially when extracting microplastics from food samples that contain more oil

[0004] When analyzing microplastics in oil-containing food samples, the existing methods cannot efficiently remove the residual oil after digestion. During density separation and filtration, microplastics may adhere to the walls of the beaker and filter cup with the oil, and it is difficult to use pure water. Rinse onto the filter membrane, and the presence of grease will affect the identification of microplastics in the later stage, thereby affecting the recovery rate and failing to meet the requirements of good QA&QC

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