CN103196898B - Method for determining trace levamisole by bipyridine ruthenium electrochemiluminescence method - Google Patents

Abstract

The invention discloses a method for measuring trace levamisole by electrochemiluminescence method using bipyridine ruthenium. A platinum electrode was used as the working electrode, and a method for the determination of trace levamisole was established by using the principle that the luminescence enhancement of ruthenium bipyridyl (Ru(bpy) ₃ ²⁺ ) contained in levamisole was enhanced by the tertiary amino group contained in levamisole. The scanning potential is 0.2V-1.3V, the high voltage of the photomultiplier tube is 800 V, and the magnification is 4 levels. In the 12 mmol/L borax base solution with pH=9.0, the concentration of levamisole is in the range of 2×10 ^-10 ~ 1×10 ^-7 mol/L, and the luminescence enhancement of lgC and ruthenium has a good linear relationship, and the detection limit is 1.76×10 ^-11 mol/L. The invention is sensitive, convenient, and has good selectivity, and is easy to automate the detection of low-concentration levamisole.

Description

Method for Determination of Trace Levamisole by Bipyridylruthenium Electrochemiluminescence

technical field

The invention relates to a method for determining trace levamisole by using bipyridine ruthenium electrochemiluminescence method.

Background technique

Because of its high quality, low price, and broad-spectrum antibacterial activity, levamisole is one of the commonly used anthelmintics in veterinary and human medicines. Drug residues of levamisole can be detected in blood and urine. The United States Pharmacopoeia has regulations on the maximum drug residue of levamisole. Therefore, it is necessary to improve the sensitivity on the previous basis to study a detection method with high selectivity for levamisole. Electrochemiluminescence is a highly sensitive and selective trace analysis method. It has been reported that the methods for the determination of levamisole have disadvantages such as low sensitivity, complicated sample processing, expensive instruments or narrow practical application range.

Contents of the invention

The purpose of the present invention is to provide a kind of high sensitivity, high selectivity, wide linear range, simple instrument, good reproducibility, the method for measuring trace levamisole with bipyridyl ruthenium electrochemiluminescence method that is easy to control.

The idea is as follows: using bipyridyl ruthenium as the electrochemiluminescent reagent, bipyridyl ruthenium has good water solubility, stable chemical properties, redox reversibility, high luminous efficiency, wide application pH range, electrochemical regeneration and long excited state lifetime And other characteristics are widely used in electrochemiluminescence (ECL) research; bipyridyl ruthenium has weak luminescence under its oxidation potential. The structure of levamisole contains a tertiary amino group, which can effectively enhance the luminescence intensity of ruthenium bipyridyl under its oxidation potential; in this way, the content of levamisole can be directly detected by the change of luminescence intensity of ruthenium bipyridyl solution after adding levamisole.

The invention utilizes the electrochemiluminescence method, levamisole enhances the luminescence intensity of bipyridyl ruthenium, and the levamisole concentration has a good linear relationship with the luminescence enhancement of bipyridyl ruthenium in the range of 2×10 ^-10 to 1×10 ^-7 mol/L.

Specific steps are as follows:

(1) Treatment of platinum electrodes:

The platinum electrode was surface polished with 1.0 μm, 0.3 μm and 0.05 μm alumina powder in turn, then soaked and washed in nitric acid (50% by volume), absolute ethanol and pure water, and ultrasonically washed for 5 minute.

(2) Detection method:

Put the platinum electrode treated in step (1) into the detection system containing 2.0×10 ^-10 ~ 1.0×10 ^-7 mol/L levamisole standard solution, and directly measure the luminescence intensity; the detection system is: 350 μL containing 5 mmol/L bipyridyl ruthenium in 12 mmol/L borax buffer solution, pH=9.0 of borax buffer solution; use MPI-A electrochemiluminescence detector for electrochemiluminescence detection, scanning potential 0.2 ~ 1.3V, photomultiplier tube The high voltage is 800 V, and the magnification is 4 levels.

(3) Drawing of standard working curve:

Add 12 mmol/L borax buffer solution containing 2.0×10 ^-10 ~ 1.0×10 ^-7 mol/L levamisole and 5 mmol/L bipyridyl ruthenium into the detection cell with a volume of 350 μL, borax buffer pH=9.0, electrochemiluminescence detection; when levamisole is in the range of 2×10 ^-10 ~1×10 ^-7 mol/L, lgC has a good linear relationship with the luminescence peak enhancement (∆ I ), and its linear regression equation It is: ∆ I =269.684lg C -20.616, linear correlation coefficient r =0.9977.

The invention overcomes the disadvantages of low detection sensitivity, complex sample processing, expensive instruments or narrow practical application range in the prior art, better improves sensitivity and selectivity, and is easy to automate the detection of low-concentration levamisole.

Description of drawings

Fig. 1 is a luminescence diagram of a platinum electrode according to an embodiment of the present invention in a 12 mmol/L borax buffer solution with a pH of 9 and a bipyridyl ruthenium concentration of 5 mmol/L.

Wherein: a means that the solution does not contain levamisole; b means that the solution contains levamisole.

Fig. 2 is a graph showing the relationship between the content of levamisole and the increase in the peak height of electrochemiluminescence in an embodiment of the present invention.

Detailed ways

Example :

(1) Treatment of platinum electrodes:

The platinum electrode was surface polished with 1.0 μm, 0.3 μm and 0.05 μm alumina powder in turn, then soaked and washed in nitric acid (50% by volume), absolute ethanol and pure water, and ultrasonically washed for 5 minute.

(2) Detection method:

Put the treated platinum electrode into the sample system containing 2.0×10 ^-10 ~ 1.0×10 ^-7 mol/L levamisole standard solution, and directly measure the luminescence intensity. The detection system is: 350 μL of 12 mmol/L borax buffer solution containing 5 mmol/L bipyridyl ruthenium, the pH of the borax buffer solution is 9.0; the electrochemiluminescence detection is performed with an MPI-A electrochemiluminescence detector, and the scanning potential is 0.2 ~ 1.3V, the high voltage of the photomultiplier tube is 800 V, and the amplification factor is 4 levels.

(3) Drawing of standard working curve:

Add 350 μL of borax buffer solution ( ^pH =9.0) containing different concentrations of levamisole and 5 mmol/L bipyridylruthenium into the detection cell for electrochemiluminescence detection ^; In the range of ⁷ mol/L, there is a good linear relationship between lg C and luminescence peak enhancement (∆ I ), the linear regression equation is: ∆ I =269.684lg C -20.616, and the linear correlation coefficient r =0.9977.

(4) Determination of levamisole content in serum samples:

No levamisole was detected in the serum sample provided by the Guilin University of Technology Hospital, so the standard recovery experiment was used; take 2 mL of serum sample, add 2 mL of saturated (NH ₄ ) ₂ SO ₄ solution into a centrifuge tube, and the sample was heated at 7000 rpm Centrifuge for 15 minutes, remove the supernatant and dialyze overnight in phosphate buffer solution (pH=7.4); add 3.0×10 ^-9 mol/L and 7.5×10 ^-10 mol/ L of levamisole, shake well and add it directly into the detection cell, use the MPI-A electrochemiluminescence detector to perform electrochemiluminescence determination of the liquid to be tested, the scanning potential is 0.2 ~ 1.3 V, the high voltage of the photomultiplier tube is 800 V, and the amplified The multiple is 4 grades, and the luminescence peak I is obtained. The concentration C of levamisole is calculated according to the calibration curve, and the recovery rate is calculated. The results are shown in Table 1:

Claims (1)

1. measure a method for trace levamisole with bipyridyl ruthenium electrogenerated chemiluminescence method, it is characterized in that concrete steps are:

(1) process of platinum electrode:

Platinum electrode is carried out surface finish process with the alumina powder of 1.0 μm, 0.3 μm and 0.05 μm successively, then successively at nitric acid, washing by soaking in absolute ethyl alcohol and pure water that concentration of volume percent is 50%, supersound washing 5 minutes after taking out;

(2) detection method:

The platinum electrode that step (1) is handled well is put into containing 2.0 × 10 ^-10~ 1.0 × 10 ^-7in the detection bodies system of the levamisol standard solution of mol/L, directly measure luminous intensity; Detection system is: 350 μ L contain 12 mmol/L borax buffer solution of 5 mmol/L bipyridyl rutheniums, borax buffer solution pH=9.0; Carry out electrochemiluminescdetection detection with MPI-A electrochemiluminescdetection detection instrument, scanning current potential 0.2 ~ 1.3V, photomultiplier high pressure is 800 V, and enlargement factor is 4 grades;

(3) drafting of standard working curve:

Be that adding containing concentration in the detection cell of 350 μ L is 2.0 × 10 at volume ^-10~ 1.0 × 10 ^-7the levamisol of mol/L and 12 mmol/L borax buffer solution of 5 mmol/L bipyridyl rutheniums, borate buffer solution pH=9.0, carries out electrochemiluminescdetection detection; Levamisol is 2 × 10 ^-10~ 1 × 10 ^-7within the scope of mol/L, the logarithm lg of its concentration cstrengthen namely with glow peak iin good linear relationship, its equation of linear regression is: i=269.684lg c-20.616, linearly dependent coefficient r=0.9977.