▎ 摘　　要

NOVELTY - A heavy metal i.e. mercuric ion in water environment, colorimetric detecting, enriching and separating method involves preparing graphene-gold nanoparticles composites. The grapheme-gold nanoparticle composite is ultrasonically dispersed in water to obtain gold nanoparticle composite standard solution, and storing. Mercury ion standard solution and environmental samples are prepared. Colorimetric determination of the concentration of mercury is performed followed by performing mercury ions in water environment enrichment and separation process and calculating the mercury in sample. USE - Method for colorimetric detecting, enriching and separating heavy metal i.e. mercuric ion in water environment. ADVANTAGE - The method enables detecting, enriching and separating heavy metal in simple, non-toxic and non-polluting manner. DETAILED DESCRIPTION - A heavy metal i.e. mercuric ion in water environment, colorimetric detecting, enriching and separating method involves preparing graphene-gold nanoparticles composites by measuring 8.0 mL concentration of 5.0 mg/mL graphene oxide, placing in a 500 mL beaker, adding deionized water, ultrasonic water bath for 30 minutes, adding 20 mL concentration of 0.05 mmol/l chloroauric acid, stirring for 2 hours, ice-cooling at 0-5 degrees C, dropwise adding 1.0mL concentration of 3% hydrazine hydrate, stirring reaction for 1 hour temperature, heating at 80 degrees C for 8 hours to complete reaction of the graphene oxide graphene, vacuum filtrating, de- washing thoroughly with deionized water, drying at 60 degrees C in vacuum to give brown graphene nano-gold composite. The grapheme-gold nanoparticle composite is ultrasonically dispersed in deionized water to obtain gold nanoparticle composite standard solution, and storing at room temperature. Mercury ion standard solution is prepared by weighing 0.2715 g mercuric chloride, dissolving in deionized water to a concentration of ion standard solution and storing at room temperature. Environmental samples are prepared by taking 1000 ml environmental water samples (such as Pi river water, groundwater and water on campus.), filtering in 5 mu m microporous membrane filter for three times distilled and concentrated to 10.0mL, and storing at room temperature and set aside. Colorimetric determination of the concentration of mercury is performed by adding 10 ml 2.5x 102 g chromogenic agent, 1.0 mL standard solution in flask, adding mixed solution of 1.0 mL phosphate buffer, 1.0 mL concentration to 1.0x 103 mol/L vitamin C solution and 1.0 mL mercury standard samples or environmental samples, and finally adding water to the mark, shaking, taking reagent blank as reference, measuring the absorbance of the solution at wavelength of 545 nm, calculating by analyzing the concentration of mercury ions in the sample, followed by performing mercury ions in water environment enrichment and separation process by taking 100 mL environmental water samples, dropping 5 ml graphene-gold nanoparticle composite standard solution at pH 4.0, mixing phosphate buffer, vitamin C solution after mixing, allowing the sample to stand for 30 minutes complete adsorption of mercury grapheme-gold nano composite material surface, and 0.1 mu m microfiltration membrane filtration and calculating the elemental mercury in the sample.