CN102183516A

CN102183516A - Nano gold colorimetric method for simply and cheaply detecting mercury ions

Info

Publication number: CN102183516A
Application number: CN 201110052259
Authority: CN
Inventors: 田丹碧; 杨孝荣; 刘会祥; 徐娟; 唐雪梅
Original assignee: Nanjing Tech University
Current assignee: Nanjing Tech University
Priority date: 2011-03-04
Filing date: 2011-03-04
Publication date: 2011-09-14
Anticipated expiration: 2031-03-04
Also published as: CN102183516B

Abstract

The invention discloses a colorimetric analysis method capable of simply and cheaply detecting mercury ions in aqueous solution. By using the characteristic that the nano gold has high light absorption coefficient, the nano gold is used as a signal element; and by using the characteristics that pyridine can induce nano gold aggregation and can also form a complex together with the mercury ions, the pyridine is used as a specificity identification element. The developed colorimetric analysis method is simple in operation, and cheap and easy to obtain.

Description

A kind of nm of gold colourimetry of detection mercury ion of cheap and simple

Technical field

The invention belongs to the analytical chemistry field, be specifically related to a kind of use nm of gold as signal element, pyridine is as the chemical colorimetry of mercury ion in the detection aqueous solution of specific recognition element.

Background technology

Mercury is a kind of material that environment and human body is had very big harm.Mercury pollution is mainly from the waste water of industrial discharges such as power plant, chlor-alkali, plastics, battery, electronics.Mercury has 3 kinds of valence states, and wherein mercury mainly exists with bivalent form in the water body.The detection of mercury at present mainly depends on analytical instrument, as high performance liquid chromatography, inductively coupled plasma mass spectrometry and atomic absorption spectrum etc.

Nanogold particle is meant the gold grain of particle diameter between 1～100 nanometer.Often be dispersed in the water formed aurosol and use, so claim collaurum or aurosol again with gold grain.In recent years, nanogold particle relies on its unique physicochemical characteristics as a kind of novel material, as high-specific surface area, high surface reaction activity, strong adsorbability etc., all obtains to use widely in fields such as material science, clinical medicine, life sciences.The absorptivity of the gold grain of 13 nanometer diameters is 2.7 * 10 ⁸M ^-1Cm ^-1, than traditional organic chromophores big 3 orders of magnitude.In addition, be dispersed in nm of gold in the solution after assembling mutually, color can become blueness from redness.Therefore, in colorimetric analysis, nm of gold is a kind of desirable color signal element.

Summary of the invention

The purpose of this invention is to provide a kind of colorimetric analysis that is used to detect the cheap and simple of mercury ion.The method is used the specific recognition element of pyridine as mercury ion, and nm of gold is as signal element.

Purpose of the present invention can reach by following measure:

A kind of nm of gold colourimetry of detection mercury ion of cheap and simple comprises the steps:

Adopt the sodium citrate reducing process that gold chloride is reduced, make the claret nano-Au solution.Certain density mercury solution is joined in the nano-Au solution.Because the mercury concentration that adds is very low (less than 1mmol L ^-1), the nm of gold color does not change.After continuing to add certain density pyridine solution in nano-Au solution, a part of pyridine and mercury ion generate complex, and remaining pyridine induced nano golden hair is given birth to and assembled, and causes solution colour to change.Change in color is relevant with the concentration of mercury ion, therefore can be used in the dimercurion that detects in the water body.

Description of drawings

Fig. 1 is the transmission electron microscope picture of (a) 13nm nm of gold; (b) transmission electron microscope picture of 24nm nm of gold; (c) the projection Electronic Speculum figure after the 24nm nm of gold is assembled;

Fig. 2 is (a) nano-Au solution; (b) contain 30 μ mol L ^-1The nano-Au solution of pyridine; (c) contain 30 μ mol L ^-1Pyridine and 30 μ mol L ^-1The uv-vis spectra of the nano-Au solution of mercury ion;

Fig. 3 is for containing mercury ion (a) 0 μ mol L respectively ^-1(b) 0.15 μ mol L ^-1(c) 0.20 μ mol L ^-1(d) 0.40 μ mol L ^-1(e) 0.60 μ mol L ^-1(f) 1.00 μ mol L ^-1(g) 2.00 μ mol L ^-1(h) 2.50 μ mol L ^-1(i) 3.50 μ mol L ^-1The 24nm nano-Au solution in add 30 μ mol L ^-1Uv-vis spectra behind the pyridine;

Fig. 4 is the typical curve of mercury ion.

Embodiment

(1) preparation of nm of gold

Nm of gold adopts sodium citrate reduction gold chloride legal system to get (see figure 1).At first, all glass apparatus all need to use chloroazotic acid to soak to remove reducing substances residual in the glass container.Accurately take by weighing HAuCl ₄.4H ₂O0.0123g adds 100mL water then in the there-necked flask in the 250mL there-necked flask.Vigorous stirring, ebuillition of heated refluxes.Accurately take by weighing 2 hydration sodium citrate 0.2849g in the 25mL volumetric flask.Get a certain amount of sodium citrate solution, add flask after water-bath is heated to 50 ℃ fast.Solution is claret to purple from colourless to light blue more at last after 15 minutes, continues heating and stops heating after 10 minutes, continues to stir cool to room temperature after 10 minutes.The size of nm of gold is relevant with the amount of the sodium citrate of adding.

(2) detection of mercury ion

In nano-Au solution, add certain density mercury ion solution respectively earlier, and then add 30 μ mol L-1 pyridine solutions, detect the uv-vis spectra of solution after 10 minutes, obtain the uv-vis spectra (see figure 3) of variable concentrations mercury ion correspondence.Use absorbance ratio E then ₅₂₅/ E ₇₀₀As ordinate, ion concentration of mercury is drawn the typical curve (see figure 4) of mercury ion as horizontal ordinate.

Claims

1. the nm of gold colourimetry of the detection mercury ion of a cheap and simple is characterized in that its use nm of gold as signal element, and uses the specific recognition element of pyridine as mercury ion.

2. the nm of gold colourimetry of the detection mercury ion of this cheap and simple according to claim 1 is characterized in that its concrete steps are:

Adopt sodium citrate reduction gold chloride to make the claret nano-Au solution, in nano-Au solution, add certain density mercury ion solution respectively earlier, and then add 30 μ mol ^L-1Pyridine solution detects the uv-vis spectra of solution after 10 minutes, obtain the uv-vis spectra of variable concentrations mercury ion correspondence, uses absorbance ratio E then ₅₂₅/ E ₇₀₀As ordinate, ion concentration of mercury is a horizontal ordinate, draws the typical curve of mercury ion.