System and method for synchronous detection and separation of negative and positive ions based on microchip electrophoresis

Abstract

The invention relates to a system and a method for synchronous detection and separation of negative and positive ions based on microchip electrophoresis. The system comprises a micro-fluidic chip, a high-voltage generation control module, a non-contact conductance detection module and a control module. The micro-fluidic chip comprises a microchip cover plate, an insulating layer and a PCB substrate. A micro pipeline is arranged at the bottom of the microchip cover plate. A detection electrode is etched on the top of the PCB substrate. The micro pipeline comprises a linear first channel and a Y-shaped second channel. A sample reservoir and a sample waste liquid tank are arranged at the two ends of the first channel respectively. The second channel comprises a first connecting part, and a second connecting part and a third connecting part which are symmetrically arranged on the front side and the rear side of the tail end of the first connecting part. A buffer solution reservoir is arranged at the head end of the first connecting part; a positive ion reservoir is arranged at the tail end of the second connecting part; and a negative ion reservoir is arranged at the tail end of the third connecting part. According to the system and the method, synchronous detection and separation of positive and negative ions can be realized by only needing the single inlet sample, the micro pipeline and the non-contact conductance detection module.

Description

technical field [0001] The invention relates to the technical field of microchip electrophoresis, in particular to a system and method for synchronous detection and separation of anions and cations based on microchip electrophoresis. Background technique [0002] In the fields of agriculture, environmental monitoring, clinical medical monitoring, food and drug monitoring, etc., the detection objects are often samples with coexistence of cations and anions, such as soil nutrient detection and PM2.5 monitoring. The bioavailable nutrients that plants can absorb in the soil are mainly K + , NH 4 + 、PO 4 3- Wait for anions and cations. PM2.5 is an important part of environmental quality monitoring, it also contains a variety of anions and cations such as F － , Cl － , NO 2 － , NO 3 － , SO 4 2－ 、K + 、Na + , NH 4 + , Ca 2+ , Mg 2+ Wait. The current detection method is to separate the sample, and then separately detect cations and anions, which makes the detecti...

AI Technical Summary

Problems solved by technology

Among them, capillary electrophoresis technology has many detection and separation methods due to its relatively long development time, but this detection technology has many defects compared with microchip electrophoresis detection technology, such as poor separation efficiency, large sample loss, and high pressure required for electrophoresis. , low system integration

However, due to the short development time and high technical difficulty of microchip electrophoresis technology, only three cases have successfully realized the simultaneous detection of anions and cations. One of them uses bipolar isokinetic electrophoresis technology to realize the simultaneous detection of anions and cations, but the detection takes too long , low precision, the second detection and separation method relies on two sets of sampling systems, and in the case of many types of ions to be measured, it is prone to aliasing and affects the detection results. In the last case, two sets of separation pipes and non- Contact conductivity detector, although the short-term detection of anions and cations is realized, but the system is very complicated and the cost is too high

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