Magnetic-nano-composite-based dispersive solid-phase extraction-chromatographic detection method of malachite green (MG) and crystal violet (CV) in water sample

Abstract

The invention relates to a magnetic-nano-composite-based dispersive solid-phase extraction-chromatographic detection method of malachite green (MG) and crystal violet (CV) in a water sample. MG and CV are two common triphenylmethane cationic dyes, and are effective antifungal and antiparasitic agents in aquiculture. However, when the dyes enter the human body, the metabolites have high residue level, and have carcinogenicity, teratogenesis, mutagenesis and other toxicities, thereby causing great hazards to the human body. Therefore, the development of a simple and sensitive method for detecting MG and CV is very necessary. The Fe3O4 / GO (graphene oxide) nano composite simultaneously has larger specific area and paramagnetism, and can well enrich the target substances in the sample and be separated from the substrate under the action of a magnetic field. After the Fe3O4 / GO nano composite is separated, a small amount of eluting agent is added for desorption, thereby achieving the goal of concentrating the sample; and HPLC (high performance liquid chromatography)-VIS is adopted to separate and detect the mixed target substance. The method has higher sensitivity; and the detection limits for MG and CV can respectively reach 0.18 and 0.19 mu g L<-1>. The method is convenient and quick, can perform solid-liquid-phase separation only by using a magnet, and avoids the operation steps of salt ion addition and centrifugation. The enrichment factor can reach 60 times or above, so the method is convenient for popularization and application.

Description

technical field

[0001] The invention relates to a method for preparing magnetic nanocomposites for dispersive solid-phase microextraction, and simultaneously using high-performance liquid chromatography to detect organic pollutants malachite green (MG) and crystal violet (CV) in water samples. It belongs to the environmental Water sample analysis technical field. Background technique

[0002] Malachite green (MG) is used as an additive mainly to keep fish alive and fresh, but after entering the human body, its metabolites have high residues and toxicity such as carcinogenic, teratogenic, and mutagenic, which are extremely harmful to the human body. Crystal Violet (CV) belongs to triphenylmethane cationic dyes, in addition to being widely used in textile, printing and dyeing and ink industries, it can also be used to dye paper, toys and some plastic products. A large amount of wastewater generated during production and use is dark in color, and its structure contains benzene...

Examples

Embodiment 1

[0016] Add 0.05mL successively to the colorimetric tube with a concentration of 2.68mg mL -1 Fe 3 o 4 / GO nanocomposite, 0.02mL10mg L -1 MG and CV mixed standard solution, ammonium acetate buffer at pH 6.0 or water sample (filter the water sample with a 0.45 μm filter membrane and adjust the pH to 6.0) 19.93 mL, react at room temperature for 15 min. The solution after the reaction was subjected to solid-liquid phase separation with a magnet, and the supernatant was discarded. Magnetic solids were ultrasonically eluted with 200 μL of acetonitrile / glacial acetic acid (V:V=4:1) eluent, separated by a magnet, filtered through a 0.45 μm filter, and 20 μL of the solution was taken for absorbance measurement on a high performance liquid chromatograph (The detection wavelength is at 600nm), according to the absorbance of the water sample and the standard series, calculate the content of MG and CV in the water sample.

Embodiment 2

[0018] Add 0.1mL successively to the colorimetric tube with a concentration of 2.68mg mL -1 Fe 3 o 4 / GO nanocomposite, 0.02mL10mgL -1 MG and CV mixed standard solution, ammonium acetate buffer at pH 5.0 or water sample (filter the water sample with a 0.45 μm filter membrane and adjust the pH to 5.0) 19.88mL, react at room temperature for 15min. After the reaction solution was separated into solid and liquid phases with a magnet, the supernatant was discarded, and the magnetic solid was eluted ultrasonically with 200 μL of acetonitrile / glacial acetic acid (V:V=4:1) eluent, separated by a magnet, and filtered through 0.45 μm. After the head is filtered, take 20 μL of the solution for absorbance measurement on a high performance liquid chromatograph (detection wavelength is 600nm), and calculate the content of MG and CV in the water sample according to the absorbance of the water sample and the standard series.

technical field

[0001] The invention relates to a method for preparing magnetic nanocomposites for dispersive solid-phase microextraction, and simultaneously using high-performance liquid chromatography to detect organic pollutants malachite green (MG) and crystal violet (CV) in water samples. It belongs to the environmental Water sample analysis technical field. Background technique

[0002] Malachite green (MG) is used as an additive mainly to keep fish alive and fresh, but after entering the human body, its metabolites have high residues and toxicity such as carcinogenic, teratogenic, and mutagenic, which are extremely harmful to the human body. Crystal Violet (CV) belongs to triphenylmethane cationic dyes, in addition to being widely used in textile, printing and dyeing and ink industries, it can also be used to dye paper, toys and some plastic products. A large amount of wastewater generated during production and use is dark in color, and its structure contains benzene...

Examples

Embodiment 1

[0016] Add 0.05mL successively to the colorimetric tube with a concentration of 2.68mg mL -1 Fe 3 o 4 / GO nanocomposite, 0.02mL10mg L -1 MG and CV mixed standard solution, ammonium acetate buffer at pH 6.0 or water sample (filter the water sample with a 0.45 μm filter membrane and adjust the pH to 6.0) 19.93 mL, react at room temperature for 15 min. The solution after the reaction was subjected to solid-liquid phase separation with a magnet, and the supernatant was discarded. Magnetic solids were ultrasonically eluted with 200 μL of acetonitrile / glacial acetic acid (V:V=4:1) eluent, separated by a magnet, filtered through a 0.45 μm filter, and 20 μL of the solution was taken for absorbance measurement on a high performance liquid chromatograph (The detection wavelength is at 600nm), according to the absorbance of the water sample and the standard series, calculate the content of MG and CV in the water sample.

Embodiment 2

[0018] Add 0.1mL successively to the colorimetric tube with a concentration of 2.68mg mL -1 Fe 3 o 4 / GO nanocomposite, 0.02mL10mgL -1 MG and CV mixed standard solution, ammonium acetate buffer at pH 5.0 or water sample (filter the water sample with a 0.45 μm filter membrane and adjust the pH to 5.0) 19.88mL, react at room temperature for 15min. After the reaction solution was separated into solid and liquid phases with a magnet, the supernatant was discarded, and the magnetic solid was eluted ultrasonically with 200 μL of acetonitrile / glacial acetic acid (V:V=4:1) eluent, separated by a magnet, and filtered through 0.45 μm. After the head is filtered, take 20 μL of the solution for absorbance measurement on a high performance liquid chromatograph (detection wavelength is 600nm), and calculate the content of MG and CV in the water sample according to the absorbance of the water sample and the standard series.

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