高效液相色谱法同时测定果蔬汁中脱氢乙酸与纳他霉素及其降解规律研究

Simultaneous determination of dehydroacetic and natamycin in juice by high performance liquid chromatography and their degradation rule

中文关键词:  脱氢乙酸  纳他霉素  高效液相色谱法  降解规律

英文关键词:dehydroacetic  natamycin  high performance liquid chromatography  degradation rule

中文摘要:

      目的 建立高效液相色谱法(high performance liquid chromatography, HPLC)同时测定果蔬汁中的脱氢乙酸与纳他霉素。方法 样品采用超声提取, 以乙腈与0.1%甲酸-水溶液为流动相进行梯度洗脱, 经过C18色谱柱分离, 采用二极管阵列检测器检测, 检测波长为310 nm和305 nm, 以外标法定量。结果 脱氢乙酸与纳他霉素在0.01~20 μg/mL浓度范围内线性关系良好(r2=0.99987), 定量限分别为1.0 mg/kg和0.5 mg/kg, 均小于等于国标方法定量限。脱氢乙酸与纳他霉素分别在5、10和50 mg/kg及0.5、1和5 mg/kg 3个水平加标回收率分别为92.44%~95.02%和91.20%~103.49%, 实验室内部变异系数分别为0.28%~0.43%和0.78%~10.44%。与国标方法对比, 在置信度为95%时的显著性检验结果较好。研究脱氢乙酸和纳他霉素的降解规律发现, 脱氢乙酸自身降解较慢, 且受到样品基质影响较小; 而纳他霉素自身降解较快, 且受到样品基质影响较大。结论 本方法准确可靠, 精密度良好, 可用于果蔬汁样品中脱氢乙酸与纳他霉素的同时测定。

英文摘要:

      Objective To establish a method for simultaneous determination of dehydroacetic and natamycin in juice by high performance liquid chromatography (HPLC). Methods The samples were extracted by ultrasonic, separated by C18 chromatographic column with acetonitrile and 0.1% formic acid solution as mobile phase for gradient elution, detected by diode array detector at the wavelength of 310 nm and 305 nm, and quantitative determined by external standard method. Results The dehydroacetic and natamycin had good linear relationships in the range of 0.01~20 μg/mL (r2=0.99987), and the limits of quantitation were 1.0 mg/kg and 0.5 mg/kg respectively, which were less than or equal to the limits of quantitation of national standard method. The recoveries of dehydroacetic spiked at 3 levels of 5, 10 and 50 mg/kg and natamycin spiked at 3 levels of 0.5, 1 and 5 mg/kg were 92.44%~95.02% and 91.20%~103.49% respectively, with the coefficients of variation of 0.28%~0.43% and 0.78%~10.44%, respectively. The significance test result of the method and the national standard method was good, when the confidence level was 95%. The degradation research found that the degradation of dehydroacetic was slow, which was less affected by the sample matrix, and the degradation of natamycin was faster, which was greatly affected by the sample matrix. Conclusion The established method is accurate, reliable and with good precision, which is suitable for simultaneous determination of dehydroacetic and natamycin in juice sample.