Method for detecting grain insectsby use of nuclear magnetic resonance technology

Abstract

The invention belongs to the technical field of grain insect detection, and specifically discloses a method for detecting grain insects by use of nuclear magnetic resonance technology. The method fordetecting the grain insects is as follows: first using insect non-infested stored grain particles as a standard product, performing low-frequency nuclear magnetic resonance testing on the standard product, using a CPMG pulse sequence to determine the spin-spin relaxation time T2 of the standard product; then taking a sample to be tested for low-frequency nuclear magnetic resonance testing, and using the CPMG pulse sequence to determine the spin-spin relaxation time T2 of the sample to be tested; and analyzing data of the spin-spin relaxation time T2 of the standard product and data of the spin-spin relaxation time T2 of the sample to be tested, when the data of the spin-spin relaxation time T2 of the standard product and the data of the spin-spin relaxation time T2 of the sample to be tested are significantly different, insect eggs, larvae or pupaes in the to-be-detected stored grain sample particles can be determined, namely, the to-be-detected stored grain has the insects. The methodfor the grain detecting insects has the advantages of being fast and simple, high in precision and good in repeatability.

Description

technical field [0001] The invention relates to the technical field of grain insect pest detection, in particular to a method for detecting grain insect pest using nuclear magnetic resonance technology. Background technique [0002] Food is the material basis for human survival and an indispensable industrial raw material, and it plays an important role in the national economy. However, in the long-term storage of grain, the stored grain is inevitably affected by environmental factors, which will cause a large number of pests and molds to grow and metabolize toxins, resulting in deterioration of grain quality and endangering food safety and human health. According to the preliminary estimate of the post-harvest grain loss survey by the World Joint Food and Agriculture Organization, the losses caused by stored grain pests account for about 50% of the stored grain losses. Among stored grain pests, moth-eating pests are the most harmful to grain reserves. Borering stored grai...

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Problems solved by technology

Among them, the biophoton emission is to detect the spontaneous photons of the organism. Due to the different biological tissue structures of hidden eggs or larvae, the number of spontaneous photons is also different. Therefore, the detection of the number of biophotons can be used theoretically, but this method High-precision biophoton number detection equipment is required, and environmental interference is difficult to remove, because it is not easy to implement and has poor practicability. It is still in the theoretical research stage

The acoustic method is to detect and identify pests through the sound of pests gnawing on grains. Since this type of sound is extremely weak, a high-precision micro-acoustic sensor is required, and the background noise in the real granary environment is extremely complex, because this type of detection is expensive. , it takes a long time and the detection effect is poor. It is still in the stage of theoretical research and is not practical.

The detection of aggregation pheromones is based on the study of the characteristic volatile substances of specific stored grain pests. Since the aggregation pheromones released by different species of pests are different, there are currently few standard gas samples and the volatile substances of the grain itself have a greater impact , still in the exploratory stage

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