CN1806880A - Solid phase micro-extraction device based on nanometer fiber - Google Patents

Abstract

The nanofiber-based solid-phase microextractor relates to a device that uses a solid adsorbent to enrich and extract samples, perform sample pretreatment and sample injection, and the device includes a syringe (1), a conical extraction tube (2), a nano Fiber filter medium (3); the front end of the syringe (1) and the rear opening of the conical extraction tube (2) can be closely matched and easily separated, and the conical extraction tube (2) is filled with a nanofiber filter medium ( 3), the front end of the conical extraction tube (2) has a small hole. A sampling needle (4) is also provided at the front end of the conical extraction tube (2), and the rear end opening of the sampling needle (4) can be closely matched with and easily separated from the front end of the conical extraction tube (2). The sample injection needle of the invention can directly inject the eluent into the sample inlets of various analytical instruments for analysis, and has the characteristics of short sample processing time, less solvent used and wide application range.

Description

Nanofiber-Based Solid-Phase Microextractors

technical field

The invention relates to a device for enriching and extracting samples by using a solid adsorbent, performing sample pretreatment and sample introduction, especially a device for micro and trace samples applied to complicated medical and biological samples, environmental samples, poisons and pollutants The sampling device for rapid enrichment and pre-purification treatment.

Background technique

Modern analysis technology is developing towards fast, micro, trace, multi-component, and high selectivity. Various new types of precision instruments emerge in an endless stream, and higher and higher requirements are put forward for the sample pretreatment process. However, 60% or more of the analysis operation time is spent on sample pretreatment, and most of the experimental errors come from the sample pretreatment process. Solid phase extraction (SPE) is an effective means of separation and purification of trace or trace substances. Most of the current commercial extraction columns use granular packing (about 30-60 μm) in liquid chromatography, and the column materials are mostly plastic. (Usually polypropylene), glass and stainless steel, with porous filter discs at both ends, and the total weight of the inner filler is 0.1-1g. When using a column solid-phase extraction device, the analyte is generally eluted and collected in a minimum volume (several milliliters) of organic solvent through steps such as activation, adsorption and extraction of the sample, and elution, and then blown off with nitrogen and concentrated to a higher concentration. Small volume for analysis. Compared with the traditional solution extraction method, the amount of SPE organic solvent is reduced. Subsequently, solid phase microextraction (SPME) technology was developed on the basis of SPE. SPME technology does not use or uses a small amount of organic solvents, which can effectively avoid environmental pollution problems. Its core component is a fibrous extraction head (length 1-2cm, diameter about 100μm). The principle of SPME is that when the extraction head is inserted into a gas or liquid sample, the analyte is adsorbed between the surface coating of the extraction head and the sample. Or when the distribution is balanced, the analyte adsorption amount in the coating is linearly related to the analyte concentration in the sample, and quantitative analysis can be performed. This technology belongs to incomplete extraction, and the sample enrichment capacity is limited, so conditions such as extraction time, temperature, and fiber coating position must be strictly controlled.

Contents of the invention

Technical problem: the purpose of the present invention is to provide a nanofiber-based solid-phase microextractor, which can overcome the single adsorbent, low enrichment efficiency, long processing time, limited application range, and still need in the prior art. There are disadvantages such as a considerable volume of organic solvent and the need to dry the solvent step, and the cost is relatively low.

Technical solution: The micro-extractor of the present invention includes a syringe, a conical extraction tube, and a nanofiber filter medium; the front end of the syringe and the rear opening of the conical extraction tube can be closely matched and easily separated, and the conical extraction tube is filled with Nanofiber filter media with a small hole at the front of the conical extraction tube.

A sampling needle is also provided at the front end of the conical extraction tube, and the rear end opening of the sampling needle can be closely matched with and easily separated from the front end of the conical extraction tube.

The nanofiber filter medium is nanofibers mixed with organic, inorganic or organic and inorganic materials, and functional nanofibers chemically modified by specific functional groups of the above-mentioned types of nanofibers as carriers. The diameter of the nanofiber is 10-1000nm, and the surface of the fiber is smooth or porous.

The volume of the conical filter tube is 10μl-1ml.

The materials of organic nanofibers are polyoxyethylene, polyvinyl alcohol, polyethylene naphthalate, polyaniline, polyacrylic acid, polyacrylonitrile, polystyrene, polymethylmethacrylate, poly-N-isopropylpropylene One of amides, polyvinyl acetate and their derivatives; the material of inorganic nanofibers is one of silicon dioxide, titanium dioxide, and carbon; natural polymers are polysaccharides, polypeptides, cellulose, polylactic acid, and casein and one of its derivatives. Various commonly used chromatographic stationary phases or biologically active substances are coated or bonded on the nanofibers.

Since the chemical structures of different types of polymers are similar to those of some extracted substances, extraction based on the principle of similar miscibility, or due to the specific interaction between modified special functional groups and sample molecules, selective extraction effects can be achieved .

Beneficial effects: due to the huge specific surface area of the nanofiber, only a small amount of adsorbent is used, and the adsorption and extraction efficiency can be greatly improved, while the column pressure is not high. The solid-phase microextractor of this design does not need a filter plate or a filter sheet, and relies on the conical tip of the conical extraction tube to support the united fibers. Using a syringe to pressurize, the sample can be quickly passed through the column, washed and eluted, and the operation Simple and easy. Compared with solid-phase extraction SPE, it uses less solvent, which can basically save the process of evaporating organic solvents and effectively avoid environmental pollution; compared with the existing SPME, it can realize the extraction of all samples, with large extraction capacity and no extraction required The equilibration time does not need to strictly control the extraction and analysis conditions. The preprocessor has the characteristics of high enrichment efficiency, strong purification effect, short sample processing time and wide application range.

Description of drawings

Fig. 1 is a structural schematic diagram of the solid phase microextraction preconditioner of the present invention.

In the above figure, there are: a syringe 1 , a tapered filter tube 2 , a nanofiber filter medium 3 , and a sampling needle 4 .

Detailed ways

The nanofiber-based solid-phase microextraction preconditioner of the present invention comprises syringe 1, conical extraction tube 2, nanofiber filter medium 3; The front end of syringe 1 and the back end opening of conical extraction tube 2 can closely match and facilitate Separated, the conical extraction tube 2 is filled with a nanofiber filter medium 3, and the front end of the conical extraction tube 2 has a small hole. A sampling needle 4 is also provided at the front end of the conical extraction tube 2 , and the rear end opening of the sampling needle 4 can be closely matched with and easily separated from the front end of the conical extraction tube 2 .

Syringe 1 is made of glass or polyethylene, polypropylene and other plastics or other non-toxic, corrosion-resistant, high-strength materials, marked with a dissolution scale, specifications: 25 μl-5ml.

The conical extraction tube 2 is made of plastics such as polyethylene and polypropylene or other non-toxic, corrosion-resistant and strong materials. There are different specifications from 10μl to 1ml, and the inlet end can be closely matched with the outlet end of the syringe 1.

Nanofiber filter medium 3 (extraction medium) is nanofibers mixed with organic, inorganic or organic and inorganic materials, and functional nanofibers chemically modified by specific functional groups of the above-mentioned types of nanofibers as carriers, with a diameter of 10-1000nm and a smooth fiber surface or porous. The extraction medium can be used in combination of one or more than two kinds. The nanofiber filter medium in the conical extraction tube 2 is less than 100 mg.

The material of the injection needle 4 is stainless steel, the shape is flat or pointed, and the tail of the needle can be closely matched with the tip of the conical extraction tube, and can also be easily separated.

The components of the device can be easily separated. Therefore, in addition to loading and eluting the sample by means of syringe pressurization, the sample can also be processed by sucking from the conical tip of the conical extraction tube 2 .

The volume of the conical filter tube is 10μl-1ml.

The materials of organic nanofibers are polyoxyethylene, polyvinyl alcohol, polyethylene naphthalate, polyaniline, polyacrylic acid, polyacrylonitrile, polystyrene, polymethylmethacrylate, poly-N-isopropylpropylene One of amides, polyvinyl acetate and their derivatives; the material of inorganic nanofibers is one of silicon dioxide, titanium dioxide, and carbon; natural polymers are polysaccharides, polypeptides, cellulose, polylactic acid, and casein and one of its derivatives. Various commonly used chromatographic stationary phases or biologically active substances are coated or bonded on the nanofibers.

Application example

1. Take a solid-phase microextraction column filled with 2 mg of 800-1000nm polystyrene fiber, draw 200 μl of 10 μg/ml trazodone (an antidepressant) aqueous solution (prepared in pH 7.4 phosphate buffer) with a syringe, and inject tube; then draw 200 μl pH7.4 phosphate buffer solution to inject and rinse the extraction tube; draw 50 μl methanol to inject and elute through the extraction tube; inject the eluate into the high-performance liquid chromatography for detection, and calculate the extraction recovery rate. Results The extraction recovery rate reached 99%.

2. Conduct the experiment with the plasma sample that is recognized as the most complicated pretreatment, prepare 10 μg/ml trazodone plasma spiked sample, add the same amount of pH12 phosphate buffer to mix, inject a total of 200 μl into the extraction tube, and then use pH12 phosphate buffer 200 μl of solution was injected to rinse the extraction tube, and 50 μl of methanol was injected into the eluent in the same way, and the eluent was injected into a high-performance liquid chromatograph for detection, and the extraction recovery rate was calculated, and the extraction recovery rate was greater than 90%. Judging from the analysis results, the sample has been processed by solid phase extraction, and a large number of interfering substances in the plasma have been removed. The operation of the device is simple, fast and convenient.

The solid-phase micro-extractor and the injection needle designed by the invention have high enrichment efficiency, simple and rapid operation. It can be used for rapid enrichment and pre-purification treatment of trace and trace samples of complex medical and biological samples, environmental samples, poisons and pollutants.

Claims (7)

1. a solid-phase microextractor based on nanofiber, it is characterized in that this microextractor comprises syringe (1), conical extraction tube (2), nanofiber filter medium (3); The front end of syringe (1) and The back end opening of the conical extraction tube (2) can be closely matched and separated conveniently. The conical extraction tube (2) is filled with nanofiber filter medium (3), and the front end of the conical extraction tube (2) has a Small hole. 2. the solid-phase microextractor based on nanofiber according to claim 1, is characterized in that being also provided with sampling needle (4) at the front end of conical extraction tube (2), the sampling needle (4) The opening at the rear end can closely match with the front end of the conical extraction tube (2) and be separated conveniently. 3. the solid-phase microextractor based on nanofiber according to claim 1, is characterized in that nanofiber filter medium (3) is the nanofiber that organic, inorganic or organic and inorganic material mix, and above-mentioned several types of nanofibers are Functional nanofibers chemically modified by specific functional groups of the carrier, or natural polymers. 4. The nanofiber-based solid-phase microextractor according to claim 3, characterized in that the diameter of the nanofiber is 10-1000nm, and the surface of the fiber is smooth or porous. 5. The nanofiber-based solid-phase microextractor according to claim 1, characterized in that the conical filter tube (2) has a volume of 10 μl-1 ml. 6. the solid-phase microextractor based on nanofiber according to claim 3, is characterized in that the material of described organic nanofiber is polyoxyethylene, polyvinyl alcohol, polyethylene naphthalate, polyaniline, One of polyacrylic acid, polyacrylonitrile, polystyrene, polymethylmethacrylate, polyN-isopropylacrylamide, polyvinyl acetate and its derivatives; the material of inorganic nanofibers is silica, Titanium dioxide, one of carbon; natural polymers are one of polysaccharide, polypeptide, cellulose, polylactic acid, casein and its derivatives. 7. The nanofiber-based solid-phase microextractor according to claim 3 or 6, characterized in that the nanofibers are coated or bonded with various commonly used chromatographic stationary phases or biologically active substances.