A high performance liquid chromatographic method was developed for the simultaneous separation and determination of vanillin and o-vanillin.Influences of mobile phase composition and column temperature on the separation were investigated.Under the condition of 5% acetic acid-acetonitrile(60∶40,by volume) as mobile phase at a flow rate of 1.0 mL/min and 25 ℃,the vanillin and o-vanillin were separated in less than 5 min.The calibration curves of vanillin and o-vanillin showed good linearities in the range of 10-240 mg/L with both correlation coefficients of 0.999 7.The limits of detection(S/N=3) for vanillin and o-vanillin were 0.06 mg/L and 0.02 mg/L,respectively.The average recoveries at three spiked levels were in the range of 99%-102% with relative standard deviations of 0.2%-0.6%.The method was successfully used for the determination of vanillin and o-vanillin in real samples with satisfactory results.

The study on chiral drugs has become one of new directions of new drugs research internationally.Analysis of chiral drugs,with increasing in importance in pharmaceutical research,is now a hot and difficult topic in international analysis science.Chiral ligand-exchange chromatography(CLEC)is one of the most popular methods to direct separation of enantiomers.This paper presents a review of the application research of CLEC in chiral separation of drug enantiomers and a discussion of the developments prospect of this technique.

A high performance capillary electrophoresis (HPCE) method has been established for the analysis of lactofen. The separation was carried out on a fused-silica uncoated capillary column(42 cm×50 μm i.d.). The analysis was completed in less than 6 min in 50 mmol/L borox-150 mmol/L sodium dihydrogen phosphate buffer(pH 9.5) at 15 kV of separation voltage and 281 nm of detection wavelength. A good linearity was obtained for lactofen in the range from 10 to 240 mg/L with correlation coefficient was 0.9997. The limits of detection(LOD) and quantification (LOQ) were 0.8 mg/L(S/N 3) and 2.0 mg/L(S/N 10),respectively. The average recoveries were in the range of 98.2-99.0%,and relative standard deviations(RSDs) were between 0.59 and 2.6%.

A method for the simultaneous separation and determination of vanillin and o-vanillin by capillary zone electrophoresis (CZE) was developed. The influences of type, concentration and pH of running buffer, and applied voltage on separation were investigated. Under the conditions of 50 mmol/L borax-150 mmol/L disodium hydrogen phosphate (pH 7.5) and applied voltage of 15 kV, the vanillin and o-vanillin were separated in 6 min. The method was proved to be robust through verification of accuracy, precision and linearity. The calibration curves of vanillin and o-vanillin showed good linearity in the range of 10-240 mg/L, and the correlation coefficients were 0.999 9 and 0.999 7, respectively. The limits of detection for vanillin and o-vanillin were 1.0 mg/L (S/N = 3). The average recoveries at three spiked levels were 99.4%-101.2% with acceptable relative standard deviations of 0.19%-0.73%. The method has been successfully used for the determination of vanillin and o-vanillin in real samples, and the assay results are satisfactory.

The compositions of Cu(Ⅱ) and L-His binary complex and Cu(Ⅱ)-L-His and chiral drug ternary complex were determined by UV spectrophotomtry.The UV spectral property of complex was also studied.The effects of different pH of solution on the stability of complex were investigated.The ratios of composition of Cu(Ⅱ) and L-His binary complex and Cu(Ⅱ)-L-His and chiral drug ternary complex were 1:2 and 1:1:1,respectively.The complex was more stable under basic condition.The enantiomers of pantoprazole were separated with a resolution of 1.4 by high performance liquid chromatography with Cu(Ⅱ)-L-His as chiral additive on a conventional C18 column.

3-methoxy-4-hydroxybenzyl ethanol acid was synthesized with guaiacol and glyoxylic acid and it was prepared for vanillin by electrochemical oxidation method.The ratio of raw materials,the method of feeding in materials,the reaction temperature,reaction time,and the concentration of alkali were studied in condensation reaction.Current strength,electrolysis time,and alkali concentration were studied in electrochemical reaction.The optimum experimental conditions were confirmed.Condensation reaction yield reached 85 %.Electrochemical oxidation reaction yield was 92 %,and total yield was 78 %.Structure of the product was characterized by using IR and 1H-NMR.

The separation of enatiomers in chiral drugs is an important subject of research in pharmaceutical field.Because enantiomers have similar physio-chemical properties,their separation is very difficult.Capillary electrophoresis(CE)has been widely applied to the enantioseparation of chiral drugs owing to its high efficiency,rapid analysis,and low buffer and sample consumption,etc.The capillary zone electrophoresis(CZE)is the most commonly used separation mode.This paper briefly reviews the applicatins of CZE for the enatioseparation of chiral drugs.The development of CZE in this field is discussed.