Quartz crystal microbalance (QCM) ethyl paraoxon flow detection device

Abstract

The invention relates to a quartz crystal microbalance (QCM) ethyl paraoxon flow detection device which comprises a specific QCM sensor and a reference QCM sensor which are arranged in a flow detection pool, wherein output ends of the two sensors are sequentially connected with an input end of a differential frequency circuit through an oscillating circuit and a shaping circuit; and the output end of the differential frequency circuit communicates with an upper computer through a frequency measurement and communication circuit. The device is high in sensitivity, high in degree of automation, simple in structure and convenient to operate; according to introduction of the reference QCM sensor, the influence of liquid viscosity, density and other factors on the detection result is eliminated, and the interference resistance is improved; and through utilizing the high specific adsorption capacity of the specific QCM sensor on the ethyl paraoxon, the device is hardly interfered by other similar substances, and therefore, the selectivity is improved.

Description

technical field [0001] The invention relates to the field of pesticide concentration detection in liquid, in particular to a quartz crystal microbalance ethyl paraoxon flow detection device. Background technique [0002] Pesticides are indispensable in modern agricultural production. At present, organophosphorus pesticides with low toxicity and high efficiency are the most widely used. Among organophosphorus pesticides, ethyl paraoxon is the most typical. Quartz crystal microbalance (QCM) is an instrument based on the piezoelectric effect of quartz crystal to measure the quality change of its electrode surface. It is widely used due to its advantages of high sensitivity, low cost, simple operation and low detection limit to nanograms. For the detection of adsorbable trace substances, such as greenhouse gases, air environment, pesticide residues, etc. [0003] Existing QCM detection devices are mainly for gas-phase substances. When applied to the detection of substances in l...

AI Technical Summary

Problems solved by technology

Most of the existing processing methods are to seal one side of the QCM crystal oscillator electrode with a rubber sleeve and add a reference item, which has disadvantages such as difficult operation, limited interference removal ability, and easy introduction of new interference.

At the same time, the frequency measurement in the existing detection process mostly relies on precision instruments, and the detection cost is high

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