A mesoporous silicon material co-modified with mercapto and amino groups and its preparation method and application

Abstract

The invention relates to a sulfydryl-amidogen modified bifunctional mesoporous silicon material synthesized by a copolycondensation method. The material can simultaneously adsorb two types of inorganic arsenic forms, namely pentavalent arsenic (As (V)) and trivalent arsenic (As (III)) under the condition of weak acid. The prepared material is put in a syringe filter and is fixed by virtue of a filter membrane so as to be made into a simple solid-phase extraction head. When solid-phase extraction is carried out, a sample solution passes through the extraction head, and the two types of inorganic arsenics in the solution are adsorbed by the material at the time; then a strategy of stage elution is adopted: the adsorbed As (V) is eluted with dilute nitric acid and collected to determine, then the adsorbed As (III) is eluted with a nitric acid / potassium iodate solution and collected to be measured, and therefore the contents of As (V) and As (III) in the sample solution are obtained. Compared with other solid-phase extraction methods, the method has the advantage that the sample only needs once extraction so that the contents of As (V) and As (III) can be respectively obtained. In addition, a device is simple and convenient, and the sample pretreatment is easily and fast completed.

Description

technical field [0001] The present invention relates to a rapid separation method of inorganic arsenic forms, more specifically to a solid-phase extraction device constructed of a mesoporous silicon material co-modified with mercapto and amino groups and a syringe needle filter for the rapid separation and enrichment of inorganic arsenic forms . Background technique [0002] Arsenic is a widely existing trace element. Arsenic pollution mainly comes from mining, metallurgy, chemical pharmaceuticals, decolorizers in the glass industry, various insecticides, rodenticides, arsenate drugs, chemical fertilizers, hard Alloys, leather and pesticides, etc. The World Health Organization (WHO) limit for arsenic in drinking water is 10 μg / L, which is lower than the detection limit of most existing trace element detectors. In addition, studies have shown that the toxicological behavior of arsenic is closely related to its existing form. For humans, inorganic arsenic is significantly mo...

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Problems solved by technology

[0003] Insufficiency of the existing solid-phase adsorption materials for the analysis of inorganic arsenic species: the existing adsorption materials can only selectively adsorb one kind of inorganic arsenic due to their single action group, but have no effect on the other arsenic species

Although this speciation analysis strategy has been widely accepted, it still has some problems: First, the subtraction calculation for the analysis components with very low content often brings large errors, which cannot reflect the real content ; Second, two measurements are required for one sample, which makes the operation troublesome; third, the oxidation or reduction operation before extraction is easy to introduce interference

[0004] The deficiency of existing solid-phase extraction device: existing solid-phase extraction device usually is that material is filled in a section of empty tube (as glass tube, polytetrafluoroethylene tube, or stainless steel tube etc.), needs in the tube during filling process Both ends of the glass wool are stuffed to fix the material

This preparation method has the following problems: first, the column pressure of the formed solid phase extraction column is very high, especially when using a smaller packing material and a higher flow rate; second, because the consistency of the packed glass wool cannot be guaranteed , leading to poor reproducibility of the prepared solid phase extraction column

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