CN101532987B

CN101532987B - Method for measuring chlorotoluron content

Info

Publication number: CN101532987B
Application number: CN2009101139792A
Authority: CN
Inventors: 李建平; 蒋复阳; 魏小平
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2009-04-11
Filing date: 2009-04-11
Publication date: 2012-02-15
Anticipated expiration: 2029-04-11
Also published as: CN101532987A

Abstract

The invention discloses a method for measuring chlorotoluron content. Obvious electrochemical signals are present on a platinum electrode surface in potassium ferricyanide solution. When molecule chlorotoluron to be measured reacts with chlorotoluron molecular engram, the electrochemical signals on the K3 [Fe(CN)6] platinum electrode change, thus an electrochemical analysis method for measuring chlorotoluron content is established. The solution to be measured is scanned using cyclic voltammetry and the scanning voltage is -0.2V to 0.6V and the linear relationship between chlorotoluron contentin concentration range of 3*10<-7>mol/L-1.5*10<-6>mol/L and peak current value I is good. The method conquers the defects of the prior technique such as very complex and has high sensitivity and good detection effect for chlorotoluron of 10<-7> mol/L.

Description

A kind of method of measuring chlorotoluron content

Technical field

The present invention relates to a kind of method of measuring chlorotoluron content, particularly a kind of electrochemical sensor of molecular imprinting fast measuring trace chlortoluron that utilizes is used for food chlortoluron Determination on content.

Background technology

Chlortoluron be a kind of on agricultural widely used substituted urea class selectivity inner sucting conduction type herbicide, mainly absorb, and the blade face action of contace poison arranged through plant roots; It is the photosynthesis electron transfer inhibitor; Because its degradation speed is slow, the residence time is long, so often be present in surface water, underground water and the crops; And their residual very low in environment, therefore research is significant to the detection method that chlortoluron has high selectivity.Molecular engram is that a kind of that development in recent years is got up has optionally synthetic method of polymers to microsphere.Along with relevant engram technology deepens continuously what study aspect the Pesticides Testing, related pesticide species is tending towards variation.The trace sensor of having reported is useful on the detection of tens kinds of agricultural chemicals such as atrazine, desmetryn, glyphosate, parathion, chloromycetin, but the research of chlortoluron molecular engram sensitive membrane sensor does not appear in the newspapers.

Summary of the invention

The object of the present invention is to provide a kind of sensor highly sensitive, that selectivity is good that utilizes, to 10 ^-7The chlortoluron of mol/L carries out method for measuring.

Conceive as follows: discover K ₃[Fe (CN) ₆] can be used as ion probe, when the chlortoluron molecular engram film forms and the chlortoluron molecular action time in platinum electrode surface, its electrochemical signals generation marked change on platinum electrode can be used for detecting the content of chlortoluron within the specific limits.

The present invention relates to molecular imprinting.When testing molecule chlortoluron and chlortoluron molecular engram film are had an effect, K ₃[Fe (CN) ₆] electrochemical signals on platinum electrode changes, the concentration of peak current and chlortoluron is linear within the specific limits.

Concrete steps are following:

(1) processing of platinum electrode:

Platinum electrode successively with the alumina powder polishing of 1.0～0.05 μ m, is washed at salpeter solution, absolute ethyl alcohol, the pure bubbly water of volumetric concentration 50% successively, taken out back supersound washing 5min.

(2) preparation of molecular engram film:

Take by weighing 0.028～0.112g N, the N-methylene-bisacrylamide, the chlortoluron solution of adding 20～80mL 0.03mol/L, the adding concentration expressed in percentage by volume is 98% methacrylic acid 5～20 μ L, ultrasonic 10min.Hold over night makes its fully effect each other.Add 30～120 μ L ammonium persulfates (0.5mol/L), initiated polymerization immerses platinum electrode in the polymerization liquid, takes out behind the 10min and dries.

(3) detection method:

Get the small beaker of a 15mL, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, drip 3 * 10 ^-4Mol/L chlortoluron solution 30 μ L.Select for use the cyclic voltammetry in the CHI660 type electrochemical workstation solution to be measured to be scanned scanning voltage-0.2～0.6V.

(4) mensuration of chlorotoluron content

Get a 15mL small beaker, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, drip the solution to be measured 50 μ L that contain chlortoluron.Select for use the cyclic voltammetry in the CHI660 type electrochemical workstation that solution to be measured is scanned, scanning voltage-0.2～0.6V reads peak point current i, according to i=0.37798C-0.78127, calculates the amount of contained chlortoluron in the solution to be measured.

The present invention has overcome prior art and had too many shortcomings such as complicacy, and is highly sensitive, for 10 ^-7The detection of mol/L chlortoluron is easy to robotization.

Description of drawings

Fig. 1 is the cyclic voltammogram of chlortoluron molecular engram film on the embodiment of the invention platinum electrode.

Fig. 2 is the graph of a relation of embodiment of the invention chlorotoluron content and cyclic voltammetry peak current.

Embodiment

Embodiment:

(1) processing of platinum electrode:

Platinum electrode successively with the alumina powder polishing of 1.0 μ m, 0.3 μ m and 0.05 μ m, is washed at salpeter solution, absolute ethyl alcohol, the pure bubbly water of volumetric concentration 50% successively, taken out back supersound washing 5min.

(2) preparation of molecular engram film:

Take by weighing 0.028g N, the N-methylene-bisacrylamide adds the chlortoluron solution of 20mL 0.03mol/L, adds the methacrylic acid (concentration expressed in percentage by volume is 98%) of 5 μ L, ultrasonic 10min.Hold over night makes its fully effect each other.Add 30 μ L ammonium persulfates (0.5mol/L), initiated polymerization immerses platinum electrode in the polymerization liquid, takes out behind the 10min and dries.

(3) detection method:

Get the small beaker of a 15mL, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, drip 3 * 10 ^-4Mol/L chlortoluron solution 30 μ L.Select for use the cyclic voltammetry in the CHI660 type electrochemical workstation that solution to be measured is scanned, scanning voltage-0.2～0.6V (like Fig. 1).

(4) drafting of standard working curve:

Get the 15mL small beaker, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, add 5 μ L3 * 10 one by one ^-4Mol/L chlortoluron solution, cyclic voltammetry scan.Chlortoluron is 3 * 10 ^-7～1.5 * 10 ^-6Be good linear relationship with peak point current i in the mol/L concentration range: i=0.37798C-0.78127, coefficient R=0.9998, chlorotoluron content and peak current relation are as shown in Figure 2.

(5) actual detected is used:

Get the farmland water sample and measure, but do not detect chlortoluron, reclaim experiment so adopt calibration curve method to carry out mark-on.Get a 15mL small beaker, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, drip the farmland WS 50 μ L that added chlortoluron.Select for use the cyclic voltammetry of CHI660 type electrochemical workstation solution to be measured to be carried out sweep measuring, scanning voltage-0.2～0.6V.Read peak point current I, and with its substitution i=0.37798C-0.78127.Calculate C.Replicate determination three times, calculate recovery rate, the result is as shown in table 1.

Table 1 mark-on recovery test data

Claims

1. method of measuring chlorotoluron content is characterized in that concrete steps are following:

(1) processing of platinum electrode:

Platinum electrode successively with the alumina powder polishing of 1.0～0.05 μ m, is washed at salpeter solution, absolute ethyl alcohol, the pure bubbly water of volumetric concentration 50% successively, taken out back supersound washing 5min;

(2) preparation of molecular engram film:

Take by weighing 0.028～0.112g N, the N-methylene-bisacrylamide, the chlortoluron solution of adding 20～80mL 0.03mol/L, the adding concentration expressed in percentage by volume is 98% methacrylic acid 5～20 μ L, ultrasonic 10min; Hold over night makes its fully effect each other; Add the ammonium persulfate of 30～120 μ L0.5mol/L, initiated polymerization immerses platinum electrode in the polymerization liquid, takes out behind the 10min and dries;

(3) detection method:

Get the small beaker of a 15mL, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, drip 3 * 10 ^-4Mol/L chlortoluron solution 30 μ L; Select for use the cyclic voltammetry in the CHI660 type electrochemical workstation solution to be measured to be scanned scanning voltage-0.2～0.6V;

(4) drafting of standard working curve:

Get the 15mL small beaker, add and contain 3 * 10 of 0.5mol/L KCl ^-4Mol/L K ₃[Fe (CN) ₆] solution 10mL, add 5 μ L 3 * 10 one by one ^-4Mol/L chlortoluron solution, cyclic voltammetry scan; Chlortoluron is 3 * 10 ^-7～1.5 * 10 ^-6Be good linear relationship with peak point current i in the mol/L concentration range: i=0.37798C-0.78127, coefficient R=0.9998.