3,3′-二氨基联苯胺柱前衍生高效液相色谱法测定酒中双乙酰

以3,3′-二氨基联苯胺(DAB)为衍生化试剂,建立了柱前衍生高效液相色谱测定酒中双乙酰含量的分析方法。双乙酰与衍生化试剂DAB在室温条件下反应10 min进行柱前衍生,并采用Shim-pack VP-ODS色谱柱(250mm×4.6 mm,4.6μm)对衍生化产物进行分离分析,以水-甲醇为流动相进行梯度洗脱,流速为0.7 mL/min,并采用配有二极管阵列检测器(DAD)的高效液相色谱仪测定,检测波长为254 nm。该法在双乙酰浓度为0.20~180μmol/L的范围内呈现良好的线性关系,相关系数(R2)为0.999,检出限(S/N=3)为0.09μmol/L,定量限(S/N=10)为0.20μmol/L,日内精密度(RSD)为1.28%(n=6)。实际酒样品的加标回收率为92.0%~103.6%,RSD为0.69%~3.45%(n=3)。该法简便快捷,结果准确,稳定性好,可以用于白酒及红酒中双乙酰含量的测定。

Determination of diacetyl in liquors by high performance liquid chromatography coupled with precolumn derivatization using 3,3'-diaminobenzidine

A method was developed for the determination of diacetyl in liquors by high performance liquid chromatography-ultraviolet (HPLC-UV) coupled with precolumn derivatization using derivatization reagent 3,3'-diaminobenzidine (DAB). Diacetyl reacted with DAB at room temperature for 10 min. Then the separation was carried out on a high performance liquid chromatograph equipped with a diode array detector (DAD). A Shim-pack VP-ODS (250 mm×4.6 mm, 4.6 μ m) column was employed using water-methanol mobile phases for gradient at a flow rate of 0.7 mL/min and detection wavelength of 254 nm. The method showed a good linearity at diacetyl concentrations from 0.20 μ mol/L to 180 μ mol/L with the correlation coefficient (R²) of 0.999. The limit of detection (S/N=3) and limit of quantification (S/N=10) were 0.09 μ mol/L and 0.20 μ mol/L, respectively. The intra-day precision (RSD) was 1.28% (n=6). The method was further evaluated in the analysis of liquor samples with the recoveries ranging from 92.0% to 103.6% and RSDs from 0.69% to 3.45% (n=3). The method is well suitable for the measurement of diacetyl in liquor samples.