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Determination of Madopar tablet in the levodopa and Benserazide hydrochloride capillary electrophoresis (14919-77-8)
2014-08-04
来源：亚科官网
This paper established a rapid, accurate, and reliable capillary electrophoresis separation and analysis methods of levodopa and Benserazide in Madopar tablet, is expected to be an effective analysis method of the drug quality control.
The 1 part of the experiment
The 1.1 main instruments and reagent
1229 capillary electrophoresis instrument, equipped with a UV detector. The detection wavelength was 214nm (Beijing Institute of Technology); uncoated fused silica capillary column (50 μ m in diameter, 60cm in length, effective length of 50cm, Hebei Yongnian optical fiber factory); the working voltage is 14kV, pressure sampling (high degree 10cm, time 5S) the background electrolyte, pH 8.5 50mmol / L borax buffer solution (O.1mol / L HC1 and O.1mol / L NaOH pH); capillary before using O.1Omol / L NaOH, water and electrophoresis buffer solution followed by flushing 5min, every time after electrophoresis with electrophoresis buffer flushing 5min
Levodopa and Benserazide (hydrochloride) control (Sigma); Madopar tablet (Shanghai Roche Pharmaceutical Ltd, batch number SH 0109), other reagents for analysis of pure water, experiment two quartz distilled water.
1.2 standard solution preparation
Accurate weighing a certain amount of levodopa and Benserazide (hydrochloride), using O.1mol / L HC1 solution of constant volume, the levodopa and Benserazide concentration was 4.0mg / mL and 2.0mg / mL, O.1mol / L diluted with HC1 before use, and the use of O.45 μ m acetate fiber filter
1.3 preparation of sample solution
5 pieces of Madopar tablet into fine powder in a mortar Zhongyan, blending. Weigh accurately about 0.50g powder in 50mL beaker, add 20mL 0.1mol / L HC1, place 4h, during ultrasound 4 times, each time 20min. And then filtering, filtrate with O.1mol / L HC1 volume to 50mL. Before using O.1mol / L HC1 and diluted with O.45 μ m acetate fiber filter
2 results and discussion
2.1 selection of buffer solution
The composition, concentration and pH electrophoresis buffer solution is an important factor affecting electrophoretic separation, buffer solution pH can affect the zeta potential, the electroosmotic flow (EOF) and analyte charged, thereby affecting the migration time and separation of analytes. Buffer concentration influence the solution viscosity coefficient, the diffusion coefficients of the analytes, zeta potential and the capillary surface, not only can affect the resolution and migration time of analytes, and may influence the peak current. The -HC1, -NaH2PO4, borax borax borax system, results show that the best effect, borax -HC1 system. At the same time, respectively, the same and different concentration of buffer solution pH and pH are the same and buffer concentration did not change at the same time the electrophoretic behavior. Experimental results are shown, with pH increased from 7 to 9, buffer solution concentration increased from 10mmol / L to 80mmol / L, levodopa and Benserazide migration time increased, separating degree increase. At the same time, along with the increase of concentration of buffer solution, the Joule heating effect obviously, baseline noise increases, the column efficiency decreased. In a certain velocity analysis of keeping a certain column efficiency and resolution, should choose borax buffer solution of -HC1 8.5 50mmol / L pH.
2.2 effect of separation voltage and injection time
The separation voltage directly affect the migration times and resolution, separation voltage increases, the migration time reduction, separation speed is improved, but the separation voltage is too high will cause the baseline noise increases, influence the separation degree. At the same time, separation voltage increases will make the analyte peak areas to reduce. The separation voltage decreases, the migration time increased, resolution increases, but the separation voltage is too low will result in peak broadening, resulting in decrease in separation efficiency. Experiment 10 ~ 20kV separation voltage, the results with the separation voltage increases, the migration time reduction, separation speed is improved, but the separation degree decreased. Considering the degree of separation and analysis speed of two factors, separation voltage of 14kV. Injection time decided to sample volume, the peak current and peak effect. With increasing sample time, peak current increased, but the sampling time of more than a certain amount peak broadening will become serious, therefore in the guarantee under certain sensitivity should try to choose short sampling time. Experimental sampling time of 2, 5, 6, 8 and 10s, experiments show that with the increase of sampling time, peak height increased gradually. But the sampling time is over 5S peak current increased slowly, peak broadening, column efficiency, this paper select the sampling time of 5S.
2.3 linear range, reproducibility and detection limit
Under the optimized experimental conditions, a series of levodopa and Benserazide standard solution were measured, levodopa and Benserazide concentration and peak height were 0.06 ~ 1.0mg / mL and 0.05 ～ 0.90mg / mL is linear in the range, the regression equation was Y (mV) =41.27x+0.2042 (mg / mL) and Y (mV) =54.73x-0.0337 (mg / mL), the linear correlation coefficients were 0.9974 and 0.9987. Continuous sampling L1 times using a standard mixed solution containing levodopa and Benserazide each 0.50mg / mL, measured levodopa and Benserazide migration time and peak height accuracy were 1.4%, 1.1% and 3.7%, 3.4%. According to the 3 times by the noise the detection limits were 0.021 and 0.017mg / mL.
2.4 sample analysis
The lmL sample solution were taken 5, diluted to 5mL content, according to the optimization of experimental conditions were good determination of Benserazide and levodopa.
3 conclusion
Through the optimization of buffer DH and concentration, separation voltage and injection time on condition of the method of levodopa and Benserazide in Madopar tablet by capillary electrophoresis was established, the actual sample analysis results show that the method is fast, accurate, reliable, is expected to be an effective analysis method of the drug quality control.
