A kind of spun gold galvanochemistry microelectrode and preparation method thereof and applicationTechnical field
The present invention relates to a kind of spun gold galvanochemistry microelectrode and make, and detection for arsenic from underwater with it.Specially refer to a kind of design and method for making of simple and easy microelectrode sensor component.
Background technology
Arsenic Contamination in Groundwater problem is the environmental problem that become international, and is detrimental to health, and long-term drinking high-arsenic underground water can cause multiple chronic disease, such as melanose, and skin lesion and various cutaneum carcinoma and lung cancer etc.Therefore, Arsenic Contamination in Groundwater is called " harm of maximum in mankind's history " by the World Health Organization (WHO).Arsenic from underwater analytical approach mainly relies on Atomic absorption or atom fluorescent luminosity method, induced plasma-mass spectrometry, and electro-spray ionization-mass spectrum, gas chromatography-mass spectrography, the methods such as HPLC-MS are carried out qualitative and quantitative analysis.These spectrum or mass spectrometric analysis method have very high sensitivity and accuracy, but also come with some shortcomings part: i) common high precision spectrum or mass spectrometer is larger, are not suitable for real time monitoring application; Ii) to links such as the collection of sample, pre-service and preservations, require stricter.Arsenic morphology is very easily subject to ambient environmental conditions (as Redox Condition, pH, Fe (II/III), organism, microbial activities) change and transforming, thereby the collection of water sample and preservation condition are had to higher requirement, deal with improperly and can cause that analysis result and actual conditions produce deviation; Iii) most of instrumentation process is comparatively complicated, and experimenter's operating experience is had relatively high expectations; Iv) operating cost of instrument is higher.Therefore, need the arsenic from underwater on-the site analysis method that development has the features such as Stability and dependability is high, cost is low, simple to operate badly.
Electrochemical analysis method is to be hopeful most to realize one of method of the on-the site analysis of arsenic from underwater, and it has the features such as highly sensitive, low-cost low, simple to operate.Yet Electrochemical Detection working electrode used is many at present encapsulates with teflon in hot environment, its technique is difficult in the same way, realizes application popular, universality.And conventional electrodes is subject to interference and the pollution of complex environment in the application of complex environment (as underground water) as electrochemical sensing detection means, the deficiencies such as stable difference, thus can not improve reliable, believable detection analysis result.
Summary of the invention
The object of this invention is to provide a kind of easy electrochemical metal microelectrode, by simple and gentle process conditions, realize the encapsulation of microelectrode is made, simplified existing circumscribed technology.This microelectrode can be applicable to the detection of arsenic from underwater, has advantages of that sane, effective, accurate and anti-complex environment disturbs, and the universality that can be electrochemical sensor is effectively promoted.
A kind of spun gold galvanochemistry microelectrode of the present invention, comprises an insulating electrode cover, and one end of described insulating electrode cover is connected with copper conductor, and the other end is connected with Herba Anoectochili roxburghii, and described copper conductor is connected by being placed in the electrocondution slurry of insulating electrode cover with Herba Anoectochili roxburghii.
Described insulating electrode cover can be for taper be as taper shape, square taper etc., and its cone tip part inserts Herba Anoectochili roxburghii.
The cone tip of described taper insulating electrode rod scribbles fluid sealant; Described fluid sealant is as being epoxy resin, phenolics, organic siliconresin or unsaturated polyester resin etc.
The described Herba Anoectochili roxburghii length that leans out cone tip seal glue is no more than 5 millimeters and is advisable.
Described insulating electrode cover is the hollow cone structure of acid and alkali-resistance material, and its material can be the insulating material such as polypropylene based polymers, glass or teflon.
Described electrocondution slurry can be conductive silver paste etc.
The method for making of spun gold galvanochemistry microelectrode of the present invention, first one end of Herba Anoectochili roxburghii is inserted to the cone tip part of taper insulating electrode cover, the tip seal of with fluid sealant, taper insulating electrode being overlapped again, normal temperature cure fluid sealant, then injecting conductive silver paste makes one end of overlapping the copper conductor of other end insertion from insulating electrode pass through the adhesion of electrocondution slurry phase with the Herba Anoectochili roxburghii termination that is inserted into taper insulating electrode cover, curing conductive slurry, prunes Herba Anoectochili roxburghii and makes the Herba Anoectochili roxburghii length that leans out taper insulating electrode cover tip seal glue be no more than 5 millimeters.
Finally, can be placed in fixed cover (as pp pipeline) by making complete spun gold galvanochemistry microelectrode, in order to Electrochemical Detection, use.
Described Herba Anoectochili roxburghii diameter 5-20 micron is advisable.
Spun gold galvanochemistry microelectrode of the present invention can be used as working electrode in electrochemical analysis method for the detection of water arsenic.The present invention can encapsulate by common epoxy resin, can pp pipeline as shell, thereby obtain can be used for detecting the spun gold microelectrode of arsenic from underwater, and there is good stability, accuracy of detection is high, antijamming capability is strong.
Beneficial effect of the present invention is:
The detecting element of the spun gold galvanochemistry microelectrode of one, this detection underground water is different from traditional conventional electrodes, adopt spun gold as sensitive material, to improve the anti-interference of electrode itself, can realize the efficient of arsenic in complex environment and accurately detect, significantly improve it and detected effect.
Two, unique easy technique is made and can under gentle condition, be realized the encapsulation to microelectrode, greatly improves its range of application.
Three, designed spun gold microelectrode device volume is less and manufacture craft is simple to operation, thereby can make galvanochemistry effectively be promoted in actual environment analyzing and testing, and is expected to obtain generalization, popular application.
Accompanying drawing explanation
Fig. 1 is spun gold microelectrode structural representation;
Fig. 2 be take the test result of the arsenic that spun gold microelectrode is 10-100ppb to concentration;
Fig. 3 is for adopting the concentration determination result of spun gold galvanochemistry microelectrode test arsenic from underwater.
In figure, 1, copper conductor, 2, taper insulating electrode cover, 3, conductive silver paste, 4, epoxide-resin glue, 5, Herba Anoectochili roxburghii.
Embodiment
Following embodiment is usingd as the explaination to the technology of the present invention content for further illustrating of content of the present invention; but flesh and blood of the present invention is not limited in described in following embodiment, those of ordinary skill in the art can and should know any simple change or replacement based on connotation of the present invention all should belong to protection domain of the presently claimed invention.
As shown in Figure 1, a kind of spun gold galvanochemistry microelectrode of the present invention, comprise a taper insulating electrode cover 2, the cone tip part of taper insulating electrode cover 2 is connected with copper conductor 1, its other end is connected with Herba Anoectochili roxburghii 5, and copper conductor 1 is mutually bonding by the electrocondution slurry 3 being placed in taper insulating electrode cover 2 with Herba Anoectochili roxburghii 5; The cone tip of taper insulating electrode cover 2 scribbles epoxide-resin glue 4.
Make spun gold galvanochemistry microelectrode, and it is as follows to adopt the electrode of making to carry out the detection example of arsenic in water:
embodiment 1
The making of spun gold galvanochemistry microelectrode of the present invention.First by 1.5 centimetres of length, the Herba Anoectochili roxburghii 5 that diameter is 12.7 microns inserts taper hollow polypropylene pipe 2, approximately 0.5 centimetre of exposed partial-length outside the mouth of pipe; With epoxide-resin glue, by taper hollow polypropylene pipe tip seal, make at normal temperatures its natural drying solidifying; Utilize conductive silver paste 3 by copper conductor 1 and Herba Anoectochili roxburghii 5 adhesions, then dry, so that electrocondution slurry solidifies, stablize; Cut off that part is exposed overlaps most advanced and sophisticated spun gold at taper insulating electrode, retain lean out epoxide-resin glue spun gold length between 1 millimeter to 2 millimeters.Finally by making complete spun gold galvanochemistry microelectrode, be placed in fixed cover, in order to using.
The electrochemical analysis condition of this example: adopt galvanochemistry square wave anodic stripping voltammetry to analyze arsenic, end liquid: N2h42HCl(2g/L), accumulating potential :-0.35V, enrichment time: 90s, equilibration time: 20s.In liquid at the bottom of 10mL, drip successively trivalent arsenic standard solution, solution concentration increases progressively from 10ppb to 100ppb, and result shows that the present invention has good linear response to arsenic, and sensitivity is 0.472 nA/ppb (R2=0.998), detect and be limited to 5.01ppb.Test result is shown in Fig. 2.
embodiment 2
Adopt the concentration of spun gold galvanochemistry microelectrode test arsenic from underwater.Adopt galvanochemistry square wave anodic stripping voltammetry to analyze, scaling method is standard addition method.End liquid: N2h42HCl(4g/L), accumulating potential :-0.35V, enrichment time: 90s, equilibration time: 20s.By 5mL underground water and 5mL N2h4at the bottom of 2HCl, liquid mixes, accumulating potential :-0.35V, enrichment time: 90s, equilibration time: 20s.Drip successively trivalent arsenic standard solution, solution concentration increases progressively from 10ppb to 100ppb, and by current-responsive, the concentration that detects arsenic from underwater is 102.12ppb (adopting inductivity coupled plasma mass spectrometry test result is 105ppb).Test result as shown in Figure 3.